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3803107

https://en.wikipedia.org/wiki/Temple%20of%20the%20Moon%20%28Peru%29

Temple of the Moon (Peru)

The Temple of the Moon is an Incan ceremonial temple on Huayna Picchu near Machu Picchu, in Peru. The site is made up of stone masonry and an open-face, shallow cave. The temple is arbitrarily named, like many of the sites in Machu Picchu. In the center of the cave is a throne carved out of rock. Beside the throne are steps that lead deeper into the cave. It is thought that the caves were used to hold mummies. The Temple of the Moon dates back 1500 years. It was rediscovered in 1936. It lies below the summit on the north side of Huayna Picchu. Architecture The Temple of the Moon consists of three structural components: an overhanging cave with superb stonework, a very tall double-jamb doorway beyond, and farther beyond, several structures including one that again uses a cave. The stone work in the Temple is said to contain the three planes of the Incan religion to be depicted: the Hanan Pacha (the heavens, or world of above), the Kay Pacha (the earth, or physical life), and the Ukju Pacha (the underworld, or world of below), represented respectively by the condor, the puma, and the snake. The temple also boasts niches and fake doors inserted in the stones, with an enormous by entrance. The premises are rectangular with the rocks of the mountains as walls. Its three doors are 1.60 meters high (in the front) and 1.00 m high (at the sides). Inside, there are six trapezoidal niches. The "temple", strictly speaking, consists of a major platform supporting a building which is raised 5 meters above the ground, with an entrance. Huaca de la Luna (Temple of the Moon), contains 6 levels, built on top of the other during a 200-year span, according to Eyewitness travel guide. Name Most scientists and authors believe that the name of the Temple is arbitrary, as many other names given to sites in Machu Picchu. Guidebook writers Ruth M Wright and Alfredo Valencia Zegarra say that they have found no indication that the lunar ritual played any part in the use of this shrine. Some have speculated that the temple gets its name from the way moonlight radiates inside the cave at night. Purpose The purpose of building of the Temple is not exactly known. Scientists have long known and documented that people lived in caves. Keeping in mind that caves, like springs, were thought to be entrances for gods, they believe the Temple's purpose was to be a place of worship to the Gods. There is a theory that it must have been a royal tomb, place of worship and look-out post. Some believe that this was a place for sacrifices, because the structure has beautiful vaulted niches and empty trapezoids of typical Inca type and in front of the cavern, there is a rock sculpted in the shape of an altar. Others think Temple of the Moon was a ceremonial bathing complex. Access The trail that leads from the summit of Huayna Picchu to the Temple and the Great Cave is very exposed and can be quite slippery. The trail is closed for maintenance and it is unclear when it will reopen. A few spots have a steel handrail cable (a via ferrata), but a fall in many places would have severe results. The trail that leads off from the main Huayna Picchu trail near the saddle is easier and safer, but still presents hazards. Expect at least a 45-minute walk in each direction from this lower trail, and at least an hour from the summit down the alternate trail to the ruins, plus the 45-minute walk back uphill and to the main trail. See also Inca trail Cusco Region References External links Huayna Picchu , Incan Trail Info Huayna Picchu and Temple of the Moon Picture Attractions in Machu Picchu : Wayna Picchu , Inti Punku , Gate of The Sun , Mandor Machu Picchu Architecture Temple of the Moon - Ruin Trips & Tours by Viva Travel Guides 1936 archaeological discoveries Archaeological sites in Peru Inca Ruins in Peru Archaeological sites in Cusco Region Tourist attractions in Cusco Region Religious buildings and structures in Peru Inca Machu Picchu

3810132

https://en.wikipedia.org/wiki/MGM-134%20Midgetman

MGM-134 Midgetman

The MGM-134A Midgetman, also known as the Small Intercontinental Ballistic Missile, was an intercontinental ballistic missile developed by the United States Air Force. The system was mobile and could be set up rapidly, allowing it to move to a new firing location after learning of an enemy missile launch. To attack the weapon, the enemy would have to blanket the area around its last known location with multiple warheads, using up a large percentage of their force for limited gains and no guarantee that all of the missiles would be destroyed. In such a scenario, the U.S. would retain enough of their forces for a successful counterstrike, thereby maintaining a deterrence. Overview The Midgetman grew out of a requirement expressed in the mid-1980s by the U.S. Air Force for a small ICBM which could be deployed on road vehicles. Fixed silos are inherently vulnerable to attack, and with the increasing accuracy of submarine-launched ballistic missiles there was a growing threat that the Soviet Union could launch large numbers of missiles from off the coast, destroying most of the U.S. ICBM force before it could be used (first strike). By producing a mobile missile which could not easily be targeted by enemy forces, and thus survive a first strike attempt, the Air Force hoped to reduce this possibility and maintain the ability to deter (second strike). It was also a response to the Soviet development of SS-24 (rail mobile) and the SS-25 (road mobile) ICBMs. System definition studies for the Small Intercontinental Ballistic Missile commenced in 1984 under an Air Force Program Office located at Norton AFB, CA, with TRW providing system engineering and technical assistance support. Contracts were awarded by the end of 1986 to Martin Marietta, Thiokol, Hercules, Aerojet, Boeing, General Electric, Rockwell and Logicon and authorization to proceed with full scale development of the MGM-134A Midgetman was granted. The first prototype missile was launched in 1989, but tumbled off course and was destroyed over the Pacific Ocean after about 70 seconds. The first successful test flight took place on April 18, 1991. Design In design the XMGM-134A was a three-stage solid-fuelled missile. Like the LGM-118 Peacekeeper it used the cold launch system, in which gas pressure was used to eject the missile from the launch canister. The rocket would only ignite once the missile was free of the launcher. The Midgetman had a range of some . Two warheads were developed for the missile: the W87-1 warhead in a Mark 21 re-entry vehicle with a yield of , and the W61 earth penetrating warhead with a yield of . Carrier vehicle: Hard Mobile Launcher The Midgetman was to be carried by an eight-wheel drive Hard Mobile Launcher (HML) vehicle. Most of these vehicles would normally remain on bases, only being deployed in times of international crisis when nuclear war was considered more likely. The Hard Mobile Launcher was radiation hardened and had a trailer mounted plow to dig the HML into the earth for additional nuclear blast protection. Cancellation With the end of the Cold War in the 1990s the U.S. scaled back its development of new nuclear weapons. The Midgetman program was therefore cancelled in January 1992. The legacy of its lighter graphite-wound solid rocket motor technology lived on in the GEM side boosters used on the Delta rockets, and the Orion stages of the Pegasus air-launched rocket. The Soviet equivalent of this missile was the RSS-40 Kuryer which was tested but cancelled in October 1991. This could have filled the role of the more cost effective Topol M road mobile ICBM. See also Nuclear warfare Nuclear weapon Intercontinental ballistic missile List of missiles References Further reading External links http://www.designation-systems.net/dusrm/m-134.html Interview with Mr. Perle about U.S. - Soviet Arms Control from the Dean Peter Krogh Foreign Affairs Digital Archives Intercontinental ballistic missiles of the United States Abandoned military rocket and missile projects of the United States

3813090

https://en.wikipedia.org/wiki/Ensulizole

Ensulizole

Ensulizole (INN; also known as phenylbenzimidazole sulfonic acid) is a common sunscreen agent. In 1999, the United States Food and Drug Administration regulated that the name ensulizole be used on sunscreen labels in the United States. Ensulizole is primarily a UVB protecting agent providing only minimal UVA protection. The scope of UVB is 290 to 340 nanometers whereas the UVA range is 320 to 400 nanometers. For better UVA protection, it must be paired with avobenzone, titanium dioxide, or zinc oxide; outside of the United States it can also be paired with a UV absorber of the Tinosorb or Mexoryl types. Because ensulizole is water-soluble, it has the characteristic of feeling lighter on skin. As such, it is often used in sunscreen lotions or moisturizers whose aesthetic goal is a non-greasy finish. The free acid is poorly soluble in water, so it is only used as its soluble salts. References External links Thomson MICROMEDEX - Sunscreen Agents (Topical) Phenylbenzimidazole sulfonic acid Benzimidazoles Sulfonic acids Sunscreening agents

3813298

https://en.wikipedia.org/wiki/NK-33

NK-33

The NK-33 and NK-43 are rocket engines designed and built in the late 1960s and early 1970s by the Kuznetsov Design Bureau. The NK designation is derived from the initials of chief designer Nikolay Kuznetsov. The NK-33 was among the most powerful LOX/RP-1 rocket engines when it was built, with a high specific impulse and low structural mass. They were intended for the ill-fated Soviet N1F Moon rocket, which was an upgraded version of the N1. The NK-33A rocket engine is now used on the first stage of the Soyuz-2-1v launch vehicle. When the supply of the NK-33 engines are exhausted, Russia will supply the new RD-193 rocket engine. It used to be the first stage engines of the Antares 100 rocket series, although those engines are rebranded the AJ-26 and the newer Antares 200 and Antares 200+ rocket series uses the RD-181 for the first stage engines, which is a modified RD-191, but shares some properties like a single combustion chamber unlike the two combustion chambers used in the RD-180 of the Atlas V and the four combustion chambers used in the RD-170 of the Energia and Zenit rocket families, and the RD-107, RD-108, RD-117, and RD-118 rocket engines used on all of the variants of the Soyuz rocket. Design The NK-33 series engines are high-pressure, regeneratively cooled oxygen-rich staged combustion cycle bipropellant rocket engines. The turbopumps require subcooled liquid oxygen (LOX) to cool the bearings. These kinds of burners are highly unusual, since their hot, oxygen-rich exhaust tends to attack metal, causing burn-through failures. The United States had not investigated oxygen-rich combustion technologies until the Integrated Powerhead Demonstrator project in the early 2000s. The Soviets, however, perfected the metallurgy behind this method. The nozzle was constructed from corrugated metal, brazed to an outer and inner lining, giving a simple, light, but strong structure. In addition, since the NK-33 uses LOX and RP-1 as propellants, which have similar densities, a single rotating shaft could be used for both turbopumps. The NK-33 engine has among the highest thrust-to-weight ratio of any Earth-launchable rocket engine; only the NPO Energomash RD-253 and SpaceX Merlin 1D engines achieve a higher ratio. The specific impulse of the NK-33 is significantly higher than both of these engines. The NK-43 is similar to the NK-33, but is designed for an upper stage, not a first stage. It has a longer nozzle, optimized for operation at altitude, where there is little to no ambient air pressure. This gives it a higher thrust and specific impulse, but makes it longer and heavier. It has a thrust-to-weight ratio of about 120:1. The predecessors of NK-33 and NK-43 are the earlier NK-15 and NK-15V engines respectively. The oxygen-rich technology lives on in the RD-170/-171 engines, their RD-180, and recently developed RD-191 derivatives, but these engines have no direct connection to the NK-33 except for the oxygen-rich staged combustion cycle technology, the kerosene/RP-1 fuel, and in case of the RD-191 and its variants like the RD-193 and the RD-181, the single combustion chamber instead of the multiple chambers in previous Russian rocket engines. History N-1 The N-1 launcher originally used NK-15 engines for its first stage and a high-altitude modification (NK-15V) in its second stage. After four consecutive launch failures and no successes, the project was cancelled. While other aspects of the vehicle were being modified or redesigned, Kuznetsov improved his contributions into the NK-33 and NK-43 respectively. The 2nd-generation vehicle was to be called the N-1F. By this point the Moon race was long lost, and the Soviet space program was looking to the Energia as its heavy launcher. No N-1F ever reached the launch pad. When the N-1 program was shut down, all work on the project was ordered destroyed. A bureaucrat instead took the engines, worth millions of dollars each, and stored them in a warehouse. Word of the engines eventually spread to the US. Nearly 30 years after they were built, rocket engineers were led to the warehouse. One of the engines was later taken to the US, and the precise specification of the engine was demonstrated on a test stand. Combustion-chamber design The NK-33 closed-cycle technology works by sending the auxiliary engines' exhaust into the main combustion chamber. This made the engine design unique. This technology was believed to be impossible by Western rocket engineers. The fully heated liquid O2 flows through the pre-burner and into the main chamber in this design. The extremely hot oxygen-rich mixture made the engine dangerous: it was known to melt thick castings "like candle wax. One of the controversies in the Kremlin over supplying the engine to the US was that the design of the engine was similar to Russian ICBM engine design. The NK-33's design was used in the later RD-180 engine, which had twice the size of the NK-33. The RD-180 engines were used (as of 2016) to power the Atlas V rocket. This company also acquired a license for the production of new engines. Sale of engines to Aerojet About 60 engines survived in the "Forest of Engines", as described by engineers on a trip to the warehouse. In the mid-1990s, Russia sold 36 engines to Aerojet General for $1.1 million each, shipping them to the company facility in Sacramento CA. During the engine test in Sacramento, the engine hit its specifications. Aerojet has modified and renamed the updated NK-33 to AJ26-58, AJ-26-59 and AJ26-62, and NK-43 to AJ26-60. Kistler K-1 Kistler Aerospace, later called Rocketplane Kistler (RpK), designed their K-1 rocket around three NK-33s and an NK-43. On August 18, 2006, NASA announced that RpK had been chosen to develop Commercial Orbital Transportation Services for the International Space Station. The plan called for demonstration flights between 2008 and 2010. RpK would have received up to $207 million if they met all NASA milestones, but on September 7, 2007, NASA issued a default letter, warning that it would terminate the COTS agreement with Rocketplane Kistler in 30 days because RpK had not met several contract milestones. Antares The initial version of the Orbital Sciences Antares light-to-medium-lift launcher had two modified NK-33 in the first stage, a solid Castor 30-based second stage and an optional solid or hypergolic third stage. The NK-33s were imported from Russia to the United States, modified, and re-designated as Aerojet AJ26s. This involved removing some electrical harnessing, adding U.S. electronics, qualifying it for U.S. propellants, and modifying the steering system. In 2010 stockpiled NK-33 engines were successfully tested for use by the Orbital Sciences Antares light-to-medium-lift launcher. The Antares rocket was successfully launched from NASA's Wallops Flight Facility on April 21, 2013. This marked the first successful launch of the NK-33 heritage engines built in early 1970s. Aerojet agreed to recondition sufficient NK-33s to serve Orbital's 16-flight NASA Commercial Resupply Services contract. Beyond that, it had a stockpile of 23 1960s- and 1970s-era engines. Kuznetsov no longer manufactures the engines, so Orbital sought to buy RD-180 engines. Because NPO Energomash's contract with United Launch Alliance prevented this, Orbital sued ULA, alleging anti-trust violations. Aerojet offered to work with Kuznetsov to restart production of new NK-33 engines, to assure Orbital of an ongoing supply. However, manufacturing defects in the engine's liquid-oxygen turbopump and design flaws in the hydraulic balance assembly and thrust bearings were proposed as two possible causes of the 2014 Antares launch failure. As announced on 5 November 2014, Orbital decided to drop the AJ-26 first stage from the Antares and source an alternative engine. On 17 December 2014, Orbital Sciences announced that it would use the NPO Energomash RD-181 on second-generation Antares launch vehicles and had contracted directly with NPO Energomash for up to 60 RD-181 engines. Two engines are used on the first stage of the Antares 100-series. Current and proposed uses RSC Energia is proposing an "Aurora-L.SK" launch vehicle, which would use an NK-33 to power the first stage and a Blok DM-SL for the second stage. Soyuz-2-1v In the early 2010s the Soyuz launch vehicle family was retrofitted with the NK-33 engine – using the lower weight and greater efficiency to increase payload; the simpler design and use of surplus hardware might actually reduce cost. TsSKB-Progress uses the NK-33 as the first-stage engine of the lightweight version of the Soyuz rocket family, the Soyuz-2-1v. The NK-33A intended for the Soyuz-2-1v was successfully hot-fired on 15 January 2013, following a series of cold-fire and systems tests of the fully assembled Soyuz-1 in 2011–2012. The NK-33 powered rocket was finally designated Soyuz-2-1v, with its maiden flight having taken place on 28 December 2013. One NK-33 engine replaces the Soyuz's central RD-108, with the four boosters of the first stage omitted. A version of the Soyuz rocket with four boosters powered by NK-33 engines (with one engine per booster) has not been built, which results in a reduced payload compared to the Soyuz-2 launch vehicle. Versions During the years there have been many versions of this engine: NK-15 (GRAU index 11D51): Initial version for the N1 first stage. NK-15V (GRAU index 11D52): Modified NK-15 optimized for vacuum operation, used on the N1 second stage. NK-33 (GRAU index 11D111): Improved version for the N1F first stage, never flown. NK-43 (GRAU index 11D112): Vacuum-optimized NK-33 for the N1F second stage, never flown. AJ26-58 and AJ26-59: Modified NK-33 by Aerojet Rocketdyne. Planned used on the Kistler K-1. AJ26-62: Modified NK-33 with additional gimbal mechanism by Aerojet Rocketdyne. Used on the Antares 100-series first stage. NK-33A (GRAU index 14D15): Refurbished NK-33. Used on the Soyuz-2-1v first stage. NK-33-1: Uprated NK-33 with gimbal mechanism. Planned used on the Soyuz-2.3 core stage. Gallery See also Comparison of orbital rocket engines References External links The Engines That Came In From The Cold!, Equinox, Channel Four Television Corporation, 2000. Documentary video on Russian rocket engine development of the NK-33 and its predecessors for the N1 rocket. (NK-33 story starts at 24:15–26:00 (program shuttered in 1974); the 1990s resurgence and eventual sale of the remaining engines from storage starts at 27:25; first use on a US rocket launch in May 2000.) NK-33's specifications NK-33 specifications & key components design (in Russian) Rocket engines of the Soviet Union Rocket engines using kerosene propellant Soviet lunar program Science and technology in the Soviet Union Antares (rocket family) Rocket engines using the staged combustion cycle

3815020

https://en.wikipedia.org/wiki/Okefenokee%20National%20Wildlife%20Refuge

Okefenokee National Wildlife Refuge

The Okefenokee National Wildlife Refuge is a 402,000‑acre (1,627 km2) National Wildlife Refuge located in Charlton, Ware, and Clinch Counties of Georgia, and Baker County in Florida, United States. The refuge is administered from offices in Folkston, Georgia. The refuge was established in 1937 to protect a majority of the 438,000 acre (1,772 km2) Okefenokee Swamp. The name "Okefenokee" is a Native American word meaning "trembling earth." A wildfire which began with a lightning strike near the center of the Refuge on May 5, 2007 eventually merged with another wildfire which had begun near Waycross, Georgia on April 16 due to a tree falling on a power line. By May 28, more than had burned in the region, or more than 900 square miles (2300 km2). Nearly 400,000 people visit the refuge each year, making it the 16th most visited refuge in the National Wildlife Refuge System. It is the largest in acreage of any that is not located in a western state. In 1999, the economic impact of tourism in Charlton, Ware, and Clinch Counties in Georgia exceeded $67 million. The refuge has a staff of 16 with a fiscal year 2005 budget of $1,451,000. The refuge also administers the Banks Lake National Wildlife Refuge. History The swamp has a rich human history including Native American settlement, explorations by Europeans, a massive drainage attempt, and intensive timber harvesting. Native Americans inhabited Okefenokee Swamp as early as 2500 BC. Peoples of the Deptford Culture, the Swift Creek Culture and the Weeden Island Culture occupied sites within the Okefenokee. The last tribe to seek sanctuary in the swamp were the Seminoles. Troops led by General Charles Rinaldo Floyd during the Second Seminole War, 1838–1842, ended the age of the Native Americans in the Okefenokee. The Suwannee Canal Company purchased 238,120 acres (963 km2) of the Okefenokee Swamp from the State of Georgia in 1891 to drain the swamp for rice, sugar cane, and cotton plantations. When this failed, the company began industrial wetland logging as a source of income. Captain Henry Jackson and his crews spent three years digging the Suwannee Canal 11.5 miles (18.5 km) into the swamp. Economic recessions led to the company's bankruptcy and eventual sale to Charles Hebard in 1901. Logging operations, focusing on the cypress, began in 1909 after a railroad was constructed on the northwest area of the swamp. More than 431 million board feet (1,020,000 m3) of timber were removed from the Okefenokee by 1927, when logging operations ceased. The Okefenokee Preservation Society, formed in 1918, promoted nationwide interest in the swamp. With the support of state and local interests and numerous conservation and scientific organizations, the Federal Government acquired most of the swamp for refuge purposes in 1936. In 1937, with Executive Order 7593 (later amended by Executive Order 7994), President Franklin Delano Roosevelt established the refuge, designating it as "a refuge and breeding ground for migratory birds and other wildlife." The establishment of Okefenokee Refuge in 1937 marked the culmination of a movement that had been initiated at least 25 years earlier by a group of scientists from Cornell University who recognized the educational, scientific, and recreational values of this unique area. In 1974, to further ensure the protection of this unique ecosystem, the interior sections of the refuge were designated a National Wilderness Area. In 1986, the Okefenokee Refuge was designated by the Wetlands Convention as a Wetland of International Importance. In September 2023, the National Park Service announced that the Okefenokee National Wildlife Refuge would be nominated as Georgia's first World Heritage Site. Geography Okefenokee NWR has an approved acquisition boundary of 519,480 acres (2,102 km2), which is 123,480 acres (500 km2) larger than its current area. Approximately 371,000 acres (1,500 km2) of the Okefenokee Swamp wetlands are incorporated into the refuge. 353,981 acres (1,432 km2) within the swamp were designated as the Okefenokee Wilderness, a part of the National Wilderness Preservation System when the Okefenokee Wilderness Act was passed in 1974, making it the third largest wilderness east of the Mississippi River. The Okefenokee Swamp is a vast bog inside a huge, saucer-shaped depression that was once part of the ocean floor. The swamp now lies 103 to above mean sea level. Peat deposits, up to thick, cover much of the swamp floor. These deposits are so unstable in spots that trees and surrounding bushes tremble by stomping the surface. Native Americans named the area "Okefenokee" meaning "Land of the Trembling Earth". Swamp habitats include open wet "prairies", cypress forests, scrub-shrub vegetation, upland islands, and open lakes. The Okefenokee Swamp is one of the world's largest intact freshwater ecosystems. It has been designated a Wetland of International Importance by the United Nations under the Ramsar Convention of 1971. The swamp is compared through research to wetlands worldwide. It is world-renowned for its amphibian populations that are bio-indicators of global health. Water from the Suwannee River Sill area is used as a standard reference by scientists throughout the world. The slow-moving waters of the Okefenokee are tea-colored due to the tannic acid released from decaying vegetation. The principal outlet of the swamp, the Suwannee River, originates in the heart of the Okefenokee and drains southwest into the Gulf of Mexico. The swamp's southeastern drainage to the Atlantic Ocean is the St. Mary's River, which forms the boundary between Georgia and Florida. The swamp contains numerous islands and lakes, along with vast areas of non-forested habitat. Prairies cover about 60,000 acres (240 km2) of the swamp. Once forested, these expanses of marsh were created during periods of severe drought when fires burned out vegetation and the top layers of peat. The prairies harbor a variety of wading birds: herons, egrets, ibises, cranes, and bitterns. Refuge staff manages 33,000 acres (130 km2) of uplands which are being restored to once-abundant longleaf pine and wiregrass habitat. Refuge staff and volunteers work to preserve the natural qualities of the swamp, provide habitat for a variety of wildlife, and provide recreational opportunities for visitors. They also conduct prescribed burns in upland areas, thin forests, create wildlife openings, plant longleaf pines, and monitor, manage, and improve wildlife populations and habitat. The Okefenokee is a rainfall-dependent system, and when periods of drought occur, the area becomes susceptible to wildfire. A 20-to-30-year cycle of drought and fire has allowed the Okefenokee to exist as the unique wetland it is. These periods cause changes in the abundance of certain plants (more grasses growing in exposed areas) the nesting success of certain wading birds (failure in extreme drought), and the location of some species of wildlife (fish migrate into deeper lakes and channels and are followed by predators). Wildlife and protected species With its varied habitats, the Okefenokee has become an area known for its abundance of plants and animals. There are 621 species of plants growing in the swamp, including the Longleaf Pine tree. Animals include 39 fish, 37 amphibian, 64 reptile, 234 bird, and 50 mammal species. The Okefenokee Swamp is world renowned for its amphibian populations that are bio-indicators of global health. Wildlife species include Florida raccoons, wading birds, ducks, American alligators and other reptiles, a variety of amphibians, North American river otters, Florida bobcats, raptors, Eastern American red foxes, wild boars, common minks, Virginia white-tailed deer, gray foxes, Florida skunks, Florida black bears, and songbirds. The swamp habitat also provides for threatened and endangered species, such as red-cockaded woodpeckers, wood storks, indigo snakes, gopher tortoises and a wide variety of other wildlife species. Facilities There are opportunities for hiking, hunting, fishing, canoeing, boating, photography and wildlife observation. Visitor center The Richard S. Bolt Visitor Center at Okefenokee National Wildlife Refuge was built in 1967, with an auditorium addition in the early 1980s. The building is cedar-sided with open, vaulted ceilings and flagstone floors. It houses exhibits, Okefenokee Wildlife League bookstore sales area, office space for staff and volunteers, storage, and a 100-seat surround-sound auditorium. Chesser Island In the late 19th century, W.T. Chesser and his family settled a small island on the eastern edge of the Okefenokee Swamp. He settled on a 592‑acre (2.4 km2) island, now known as Chesser Island. The Chesser homestead still stands on the island. The last of the Chessers left the island in 1958, but many members of the Chesser family remain in the local area. Fishing Lakes and slow-flowing water trails, called "runs," cover much of the Okefenokee. More than 60 lakes dot the refuge, with depths ranging from a few feet to . The largest, Billy's Lake, is 3½ miles long and 100 to wide. Fishing is permitted year round in accordance with Georgia State fishing laws. Using live bait fish or trot lines is prohibited. Canoeing and boating There are of trails in the swamp, of which 70 are open to day-use motorboat and under. Seven overnight shelters are available in the swamp's interior. The refuge has six different boating trails (Red, Green, Blue, Purple, Orange, and Brown) giving users a choice of twelve different overnight canoe trips. Trails Swamp Island Drive – a driving, biking and walking loop. Scattered throughout the drive are walking trails, wildlife openings and hardwood plots. Additionally, the drive leads to the Chesser Homestead, Boardwalk and Observation tower. There are several canoe trails and camping shelters for visitors to enjoy. Some useful coordinates for canoeing and camping: Refuge's East Entrance coordinates (Visitor Center): N30.73803° W082.14135° Monkey Lake: N30.67493° W82.20594° Monkey Lake Shelter: N30.67439° W82.20601° Coffee Bay Shelter: N30.76133° W082.22659° Restroom on Suwannee Canal: N30.73811° W82.17332° Coordinates for junction points (see Okefenokee National Wildlife Refuge Map to locate them): Junction of Suwannee Canal and Prairie Lakes Run: N30.73708° W82.17473° Junction of Prairie Lakes Run and Tater Rake: N30.72608° W082.18269° Those canoeing North on Prairie Lakes Run towards Coffee Bay Shelter can take Tater Rake as a shortcut. Useful coordinates on that shortcut: Tater Rake and Suwannee Canal: N30.73704° W082.18188° North End of Tater Rake & Cutoff (from Suwannee Canal): N30.73641° W82.17790° Access There are three major entrances to Okefenokee National Wildlife Refuge, each with its own facilities and special character. From the open, wet "prairies" of the east side to the forested cypress swamps on the west, Okefenokee is a mosaic of habitats, plants, and wildlife. Entrance fees are required at each entrance. East Entrance – main U.S. Fish and Wildlife Service entrance, located southwest of Folkston, Georgia West Entrance – Stephen C. Foster State Park, located east of Fargo, Georgia North Entrance – Okefenokee Swamp Park, located eight miles (13 km) south of Waycross, Georgia See also Bugaboo scrub fire List of National Wildlife Refuges Okefenokee Swamp References External links Okefenokee National Wildlife Refuge homepage -- includes map and photos of the May 2007 wildfire FWS profile of Okefenokee NWR Recreation.gov overview Okefenokee Swamp Park homepage National Wildlife Refuges in Georgia (U.S. state) National Wildlife Refuges in Florida Flooded grasslands and savannas Wetlands of Georgia (U.S. state) Wetlands of Florida Protected areas of Baker County, Florida Protected areas of Charlton County, Georgia Protected areas of Clinch County, Georgia Protected areas of Ware County, Georgia Protected areas established in 1937 Ramsar sites in the United States Landforms of Baker County, Florida Landforms of Charlton County, Georgia Landforms of Clinch County, Georgia Landforms of Ware County, Georgia

3816650

https://en.wikipedia.org/wiki/Commercial%20use%20of%20space

Commercial use of space

Commercial use of space is the provision of goods or services of commercial value by using equipment sent into Earth orbit or outer space. This phenomenon – aka Space Economy (or New Space Economy) – is accelerating cross-sector innovation processes combining the most advanced space and digital technologies to develop a broad portfolio of space-based services. The use of space technologies and of the data they collect, combined with the most advanced enabling digital technologies is generating a multitude of business opportunities that include the development of new products and services all the way to the creation of new business models, and the reconfiguration of value networks and relationships between companies. If well leveraged such technology and business opportunities can contribute to the creation of tangible and intangible value, through new forms and sources of revenue, operating efficiency and the start of new projects leading to multidimensional (e.g. society, environment) positive impact. Examples of the commercial use of space include satellite navigation, satellite television and commercial satellite imagery. Operators of such services typically contract the manufacturing of satellites and their launch to private or public companies, which form an integral part of the space economy. Some commercial ventures have long-term plans to exploit natural resources originating outside Earth, for example asteroid mining. Space tourism, currently an exceptional activity, could also be an area of future growth, as new businesses strive to reduce the costs and risks of human spaceflight. The first commercial use of outer space occurred in 1962, when the Telstar 1 satellite was launched to transmit television signals over the Atlantic Ocean. By 2004, global investment in all space sectors was estimated to be US$50.8 billion. As of 2010, 31% of all space launches were commercial. History The first commercial use of satellites may have been the Telstar 1 satellite, launched in 1962, which was the first privately sponsored space launch, funded by AT&T and Bell Telephone Laboratories. Telstar 1 was capable of relaying television signals across the Atlantic Ocean, and was the first satellite to transmit live television, telephone, fax, and other data signals. Two years later, the Hughes Aircraft Company developed the Syncom 3 satellite, a geosynchronous communications satellite, leased to the Department of Defense. Commercial possibilities of satellites were further realized when the Syncom 3, orbiting near the International Date Line, was used to telecast the 1964 Olympic Games from Tokyo to the United States. Between 1960 and 1966, NASA launched a series of early weather satellites known as Television Infrared Observation Satellites (TIROS). These satellites greatly advanced meteorology worldwide, as satellite imagery was used for better forecasting, for both public and commercial interests. On April 6, 1965, the Hughes Aircraft Company placed the Intelsat I communications satellite geosynchronous orbit over the Atlantic Ocean. Intelsat I was built for the Communications Satellite Corporation (COMSAT), and demonstrated that satellite-based communication was commercially feasible. Intelsat I allowed for near-instantaneous contact between Europe and North America by handling television, telephone and fax transmissions. Two years later, the Soviet Union launched the Orbita satellite, which provided television signals across Russia, and started the first national satellite television network. Similarly, the 1972 Anik A satellite, launched by Telesat Canada, allowed the Canadian Broadcasting Corporation to reach northern Canada for the first time. In 1980, Europe's Arianespace became the world's first commercial launch service provider. Beginning in 1997, Iridium Communications began launching a series of satellites known as the Iridium satellite constellation, which provided the first satellites for direct satellite telephone service. Spaceflight The commercial spaceflight industry derives the bulk of its revenue from the launching of satellites into the Earth's orbit. Commercial launch providers typically place private and government satellites into low Earth orbit (LEO) and geosynchronous Earth orbit (GEO). The Federal Aviation Administration (FAA) has licensed six commercial spaceports in the United States: Wallops Flight Facility, Kodiak Launch Complex, Spaceport Florida, Kennedy Space Center, Cape Canaveral Space Force Station, and the Vandenberg Air Force Base. Launch sites within Russia, France, and China have added to the global commercial launch capacity. The Delta IV, Atlas V, and Falcon family of launch vehicles are made available for commercial ventures for the United States, while Russia promotes eight families of vehicles. Between 1996 and 2002, 245 launches were made for commercial ventures while government (non-classified) launches only total 167 for the same period. Commercial space flight has spurred investment into the development of an efficient reusable launch vehicle (RLV) which can place larger payloads into orbit. Several companies such as SpaceX and Blue Origin are currently developing new RLV designs. In the United States, Office of Commercial Space Transportation (generally referred to as FAA/AST or simply AST) is the branch of Federal Aviation Administration (FAA) that approves any commercial rocket launch operations—that is, any launches that are not classified as model, amateur, or "by and for the government." Satellites and equipment Satellite manufacturing Commercial satellite manufacturing is defined by the United States government as satellites manufactured for civilian, government, or non-profit use. Not included are satellites constructed for military use, nor for activities associated with any human space flight program. Between the years of 1996 and 2002, satellite manufacturing within the United States experienced an annual growth of 11%. The rest of the world experienced higher growth levels of around 13%. Ground equipment manufacturing Operating satellites communicate via receivers and transmitters on Earth. The manufacturing of satellite ground station communication terminals (including VSATs), mobile satellite telephones, and home television receivers are a part of the ground equipment manufacturing sector. This sector grew through the latter half of the 1990s as it manufactured equipment for the satellite services sector. Between the years of 1996 and 2002 this industry saw a 14% annual increase. Transponder leasing Businesses that operate satellites often lease or sell access to their satellites to data relay and telecommunication firms. This service is often referred to as transponder leasing. Between 1996 and 2002, this industry experienced a 15% annual growth. The United States accounts for about 32% of the world's transponder market. Subscription satellite services In 1994, DirecTV debuted direct broadcast satellite by introducing a signal receiving dish 18inches in diameter. In 1996, Astro started in Malaysia with the launch of the MEASAT satellite. In November 1999, the Satellite Home Viewer Improvement Act became law, and local stations were then made available in satellite channel packages, fueling the industry's growth in the years that followed. By the end of 2000, DTH subscriptions totaled over 67 million. Satellite radio was pioneered by XM Satellite Radio and Sirius Satellite Radio. XM's first satellite was launched on March 18, 2001 and its second on May 8, 2001. Its first broadcast occurred on September 25, 2001, nearly four months before Sirius. Sirius launched the initial phase of its service in four cities on February 14, 2002, expanding to the rest of the contiguous United States on July 1, 2002. The two companies spent over $3 billion combined to develop satellite radio technology, build and launch the satellites, and for various other business expenses. Satellite imagery Satellite imagery (also Earth observation imagery or spaceborne photography) are images of Earth or other planets collected by imaging satellites operated by governments and businesses around the world. Satellite imaging companies sell images by licensing them to governments and businesses such as Apple Maps and Google Maps. Satellite telecommunications Satellites can be used to transmit and receive Internet services from space to any place in the planet Earth. Satellite navigation A satellite navigation or satnav system is a system that uses satellites to provide autonomous geo-spatial positioning. It allows small electronic receivers to determine their location (longitude, latitude, and altitude/elevation) to high precision (within a few centimeters to metres) using time signals transmitted along a line of sight by radio from satellites. The system can be used for providing position, navigation or for tracking the position of something fitted with a receiver (satellite tracking). The signals also allow the electronic receiver to calculate the current local time to high precision, which allows time synchronisation. These uses are collectively known as Positioning, Navigation and Timing (PNT). Satnav systems operate independently of any telephonic or internet reception, though these technologies can enhance the usefulness of the positioning information generated. Space tourism Space tourism is human space travel for recreational purposes. There are several different types of space tourism, including orbital, suborbital and lunar space tourism. To date, orbital space tourism has been performed only by the Russian Space Agency. Work also continues towards developing suborbital space tourism vehicles. This is being done by aerospace companies like Blue Origin and Virgin Galactic. In addition, SpaceX (an aerospace manufacturer) announced in 2018 that they are planning on sending space tourists, including Yusaku Maezawa, on a free-return trajectory around the Moon on the Starship. Commercial recovery of space resources Commercial recovery of space resources is the exploitation of raw materials from asteroids, comets and other space objects, including near-Earth objects. Minerals and volatiles could be mined then used in space for in-situ utilization (e.g. construction materials and rocket propellant) or taken back to Earth. These include gold, iridium, silver, osmium, palladium, platinum, rhenium, rhodium, ruthenium and tungsten for transport back to Earth; iron, cobalt, manganese, molybdenum, nickel, aluminium, and titanium for construction; water and oxygen to sustain astronauts; as well as hydrogen, ammonia, and oxygen for use as rocket propellant. There are several commercial enterprises working in this field, including Planetary Resources and Deep Space Industries. The first in-space transaction of resources is contracted by NASA to four companies to sell NASA collected lunar regolith on the Moon. Regulation Beyond the many technological factors that could make space commercialization more widespread, it has been suggested that the lack of private property, the difficulty or inability of individuals in establishing property rights in space, has been an impediment to the development of space for both human habitation and commercial development. Since the advent of space technology in the latter half of the twentieth century, the ownership of property in space has been murky, with strong arguments both for and against. In particular, the making of national territorial claims in outer space and on celestial bodies has been specifically proscribed by the Outer Space Treaty, which had been, , ratified by all spacefaring nations. In November 25, 2015 President Obama signed the U.S. Commercial Space Launch Competitiveness Act (H.R. 2262) into law. The law recognizes the right of U.S. citizens to own space resources they obtain and encourages the commercial exploration and utilization of resources from asteroids. According to the article § 51303 of the law: See also Space launch market competition Commercial astronaut Private spaceflight Satellite Internet access Space industry Space manufacturing Space-based industry Space pollution References Futron Corporation (2001) "Trends in Space Commerce". Retrieved January 24, 2006 External links Ethical Issues Lunar Land Grab Office of Space Commercialization Property Rights Government Policy Mir Space Station Privatization Satellite broadcasting Space industry 1962 introductions Space-based economy

3829882

https://en.wikipedia.org/wiki/One%20Night%20%40%20the%20Call%20Center

One Night @ the Call Center

One Night @ the Call Center is a novel written by Chetan Bhagat, first published in 2005. The novel revolves around a group of six call center employees working at a call center in Gurgaon, Haryana, India. The themes involve the anxieties and insecurities of the young Indian middle class, such as career, inadequacy, marriage, and family conflicts. The book was the second best-selling novel from the author after Five Point Someone. Plot The book begins with a frame story recounting a train journey from Kanpur to Delhi. During the journey, the author meets a beautiful girl who offers to tell him a story on the condition that he has to make it his second book. After a lot of hesitation, the author agrees. The story is about six people working in a call center and relates the events that happen one night when get a phone-call from 'God'. Claimed to be based on a true story, the author uses Shyam Mehra (alias Sam Marcy) as the narrator and protagonist, who is one among the six call center employees. Shyam loves but has lost Priyanka, who is now planning an arranged marriage with someone else, Vroom loves Esha, Esha wants to be a model, Radhika is in an unhappy marriage with a demanding mother-in-law, and Military Uncle wants to communicate with his grandson. They all hate Bakshi, their cruel and somewhat sadistic boss. To cheer themselves up, all the lead characters of the novel decide to go to a night club. After enjoying for a while, they leave back for the office. While returning, they face a life-threatening situation when their vehicle crashes into a construction site hanging over a mesh of iron construction rods. As the rods began to yield slowly, they start to panic. They are unable to call for help as there is no mobile phone network at that place, but Shyam's mobile phone starts ringing. The phone call is from God, who speaks modern English. He speaks to all of them and gives them suggestions to improve their life, and advises them on how to get their vehicle out of the construction site. The conversation with God motivates the group to such an extent that they get ready to face their problems with determination and motivation. Meanwhile, Vroom and Shyam hatch a plan to throw Bakshi out of the call center and prevent the closing of the call center, whose employees are to be downsized radically. When they return to the call center, they carry out their plan successfully. At the end, each character has fixed a part of their life, and the author invites readers to identify aspects of themselves and their lives that they would like to change. Characters ● Shyam Mehra (Sam Marcy) - The main protagonist, Priyanka's ex-boyfriend, and Vroom's best friend. He is 26 years old and is perpetually afraid to propose to Priyanka for marriage. Due to Priyanka's mother distrusting him, Priyanka and Shyam breakup. He is always a slave to Bakshi. ● Priyanka Sinha - Shyam's ex-girlfriend who he later reunites with. She was going to get married abroad to Ganesh, which made Shyam find it difficult to look her in the eyes. ● Varun Malhotra (Victor Meller), aka Vroom - He is nicknamed Vroom because of his love for vehicles. He is 22 years old. He has a crush on Esha though he never admits it straight. He tries proposing to Esha but she rejects it because of his obsession with girls, pizza, and vehicles. His parents' divorce made him depressed, though he doesn't show his sadness as he hates sympathy. At the end of the book, Esha accepts a date with Vroom. He hates Bakshi and never volunteers to help Bakshi, unlike Shyam. ● Esha Singh (Eliza Singer) - An aspiring model. She always wears modern dresses and was voted THE HOTTEST CHICK by her office colleagues. She came to Chandigarh against her parents will. By the end of the book, she becomes a member of NGO and accepts a date with Vroom. ● Radikha Jha (Regina Jones) - The only married member of the group. She married her college boyfriend Anuj for love, living with his traditional family. Her mother-in-law hates her and always complains about her to Anuj which makes Anuj berate at her, as he only trusts his mother. It is later revealed that Anuj is having an extra-marital affair and so Radhika divorces him and moves in with Esha. ● Military Uncle - Military Uncle lives alone and is having some problems with his son and grandson, but at the end he realizes his mistake and decide to apologize. Military Uncle works at the call centre to earn a little money aside from the pension that he gets. ● Subhash Bakshi - Shyam's, Priyanka's, Esha's, Vroom's and Radhika's boss. An idiot who is going to be transferred to Boston thus saving him from getting fired. He took credit for a website manual which was made by Shyam and Vroom. ● Shefali - Shyam's second ex-girlfriend. Shyam wanted to move on from Priyanka and thus started dating Shefali. Shefali is a rather minor character. Translations and Adaptations The book has been translated into Hindi and was published by Prabhat Prakash. It was translated to Sinhala by Dileepa Jayakody and published in 2009 as Halo! Halo!. The book was also adapted into a film titled Hello in 2008. References 3. ^"One Night @ the Call Center: A Tale of Life, Love, and the Corporate World"21 February 2023. 2005 Indian novels Indian novels adapted into films Novels set in India Haryanavi culture Gurgaon Rupa Publications books Novels by Chetan Bhagat Novels set in one day

3832875

https://en.wikipedia.org/wiki/Actigraphy

Actigraphy

Actigraphy is a non-invasive method of monitoring human rest/activity cycles. A small actigraph unit, also called an actimetry sensor, is worn for a week or more to measure gross motor activity. The unit is usually in a wristwatch-like package worn on the wrist. The movements the actigraph unit undergoes are continually recorded and some units also measure light exposure. The data can be later read to a computer and analysed offline; in some brands of sensors the data are transmitted and analysed in real time. Purpose Sleep Sleep actigraphs are generally watch-shaped and worn on the wrist of the non-dominant arm for adults and usually on the ankle for children. They are useful for determining sleep patterns and circadian rhythms and may be worn for several weeks at a time. In the medical setting, traditional polysomnography has long been cited as "the 'gold standard' for sleep assessment." Since the 1990s, however, actigraphy has increasingly been used to assess sleep/wake behavior; especially for young children. Studies have found actigraphy to be helpful for sleep research because it tends to be less expensive and cumbersome than polysomnography. Unlike polysomnography, actigraphy allows the patient to be movable and to continue her or his normal routines while the required data are being recorded in his or her natural sleep environment; this may render the measured data more generally applicable. As sleep actigraphs are more affordable than polysomnographs, their use has advantages, particularly in the case of large field studies. However, actigraphy cannot be considered as a substitute to polysomnography. A full night sleep measured with polysomnography may be required for some sleep disorders. Indeed, actigraphy may be efficient in measuring sleep parameters and sleep quality, however it is not provided with measures for brain activity (EEG), eye movements (EOG), muscle activity (EMG) or heart rhythm (ECG). Actigraphy is useful for assessing daytime sleepiness in place of a laboratory sleep latency test. It is used to clinically evaluate insomnia, circadian rhythm sleep disorders, excessive sleepiness. It is not recommended for the diagnosis of restless legs syndrome. It is also used in assessing the effectiveness of pharmacologic, behavioural, phototherapeutic or chronotherapeutic treatments for such disorders. The data, recorded over time, is in some cases more relevant than the result of polysomnography, particularly in assessing circadian rhythms and disorders thereof as well as insomnia. With the actigraphy it is also possible to determine some general information related to the sleep and the sleep quality of the subject, such as his/her chronotype, the sleep onset latency, the total sleep duration, the sleep consolidation (sleep efficiency), the time spent in bed, movements, and the sleep cycle. Research showed that both sleep and wake are not equally assessed by actigraphy devices. When compared, data collected through polysomnographs and actigraphs defines sensitivity; which is the proportion of sleep correctly detected by both methods. Actigraphy reveals itself to be more likely to detect sleep than wake phases. Actigraphy has been actively used in sleep-related studies since the early 1990s. It has not traditionally been used in routine diagnosis of sleep disorders, but technological advances in actigraph hardware and software, as well as studies verifying data validity, have made its use increasingly common. The main reason for this development is the fact that, while retaining mobility, actigraphy offers reliable results with an accuracy that is close to those of polysomnography (above 90% for estimating total sleep time but dropping to 55% for a 4 - way sleep stage estimation problem). The technique is increasingly employed in new drug clinical trials where sleep quality is seen as a good indicator of quality of life. The technique has also been used in studies with individuals in both health and disease, e.g., Alzheimer's and fibromyalgia, conditions. Activity Activity actigraphs are worn and used similarly to a pedometer: around the waist, near the hip. They are useful for determining the amount of wake-time activity, and possibly estimating the number of calories burned, by the wearer. They are worn for a number of days to collect enough data for valid analysis. Movement Movement actigraphs are generally larger and worn on the shoulder of the dominant arm. They contain a 3D actigraph as opposed to a single dimension one, and have a high sample rate and a large memory. They are used for only a few hours, and can be used to determine problems with gait and other physical impairments. The actigraph unit The unit itself is an integrate electronic device which generally embeds: an accelerometer, a real time clock or timer to start/stop the actigraph recording at specific times, and to record accumulate values for a specific time frame, a non-volatile memory to store the resulting values, an optional low-pass filter which filters out everything except the 2–3 Hz band, thereby ensuring external vibrations are ignored, and an interface, usually USB, serial, or low-power wireless, to program the timer and download the data from memory. Measurements Devices used for actigraphy collect data generated by movements. In order to make the data usable for practice and sleep medicine, movements are translated into digital data by actigraphs. Several devices and computer software are available, and assessment can vary depending on combination of chosen device, procedure and software program. Actigraphs have a number of different ways of accumulating the values from the accelerometer in memory. ZCM (zero crossing mode) counts the number of times the accelerometer waveform crosses 0 for each time period. PIM (proportional integral mode) measures the area under the curve, and adds that size for each time period. TAT (time above threshold) uses a certain threshold, and measures the length of time that the wave is above a certain threshold. Literature shows that PIM provides most accurate measurements for both sleep and activity, though the difference with ZCM is marginal. Features Actigraph units vary widely in size and features and can be expanded to include additional measurements. However, there are a number of limiting factors: Fastest sample rate: 1-minute intervals provide adequate detail to measure sleep, but could be too slow for measuring other parameters. Amount of memory: Together with sample rate, the amount of memory determines how long measurements can be taken. Battery usage: Some actigraphs have a short battery life. Weight: the heavier the actigraph, the more disruptive its use. Water resistance: for proper measurements it is often desirable that the actigraph be worn in the shower, bathtub, or even while swimming/diving. For some uses, the following are examples of additional features: Watch functionality: making the device more attractive to the user. User input: most actigraphs now include a button so the user can indicate a specific event that occurs, for example lights out at bedtime. Subjective user input: for example a query function to allow surveys at specific times. Sensors which monitor: temperature ambient light sound levels Parkinsonian tremor skin resistance a full EEG data stream Advantages One advantage of actigraphy methods over polysomnography methods is about duration. Recording is longer than laboratory settings, duration of collection of data may be adapted to each patient and highlight information that cannot be found through one-night measurements such as sleep habits. Actigraphy also captures daytime activity, which is not captured by polysomnography. Actigraphy turns out to be especially adapted to pediatric and elderly patients. Disadvantages The actigraph is recorded at home, and therefore a high compliance is needed: patients need to complete a sleep diary and always wear the watch. Sometimes, the actigraph doesn't properly record sleep; for example, a nap during a car ride isn't always logged as sleep. In contrast, showers close to the sleep period can be erroneously recorded as sleep. These false positives are relatively common: while actigraphy is good at detecting sleep patterns (sensitivity: 0.965), it has its difficulties in detecting wake periods (specificity: 0.329). As an electronic device, there can be unobserved technical malfunctions that detrimentally affect actigraphic measurement. Consumer electronics devices Some consumer electronics devices, such as the Oura Ring and the Huawei Honor Band, employ actigraphy to estimate sleep patterns. Other devices, such as the Fitbit Alta HR, have been found to provide equivalent estimates across all traditional sleep parameters, compared to more traditional actigraph units. References External links American Academy of Sleep Medicine—Parameters for the Use of Actigraphy in the Assessment of Sleep and Sleep Disorders: An Update for 2007 American Academy of Sleep Medicine – Practice parameters for the role of actigraphy in the study of sleep and circadian rhythms: An update for 2002 Reliability of Accelerometry-Based Activity Monitors: A Generalizability Study. Gregory J. Welk, Jodee A. Schaben, and James R. Morrow, Jr. Medicine & Science In Sports & Exercise, Vol. 36, No. 9, pp. 1637–1645, 2004. – Medicine & Science in Sports & Medicine, the official Journal of the American College of Sports Medicine Measuring instruments Neurology procedures Circadian rhythm Sleep

3834820

https://en.wikipedia.org/wiki/Astra%20Digital%20Radio

Astra Digital Radio

Astra Digital Radio (ADR) was a system used by SES for digital radio transmissions on the early Astra satellites, using the audio subcarrier frequencies of analogue television channels. It was introduced in 1995. As of February 2008, there were still 51 stations transmitting in this format. ADR ceased on 30 April 2012 when analogue broadcasts on Astra 19.2°E ended. Details The format used one mono audio subcarrier, which was normally allocated to an additional audio track or radio station, or one channel of a stereo audio track/station. The carrier was digitally modulated and carried a 192 kbit/s, 48 kHz sampled MPEG-1 Layer II (MP2) encoded signal. 9.6 kbit/s was available for data. Special receivers were required to listen to ADR stations, although some combined analogue/digital satellite boxes and later standard analogue boxes were equipped to decode it. ADR was succeeded by DVB-S, with which it is incompatible, despite both being transmitted using MP2 and generally at the same bitrates. As a result, when the final analogue switch-off on the Astra 1 satellites occurred, ADR became obsolete. The majority of the channels to have been broadcast using ADR were in the German language. Because of this, the system can in a way be seen to have replaced the German Digitales Satellitenradio system, dating from the 1980s, which used an entire satellite transponder to carry 16 NICAM encoded radio stations, and which closed in 1999. Channel Listing DLF DKultur Deutsche Welle Bayerischer Rundfunk Bayern 1 Bayern 2 Bayern 3 BR Klassik B5 plus Hessischer Rundfunk You FM hr1 hr2 hr3 hr4 hr-info hr1 plus Hr-klassik Mitteldeutscher Rundfunk MDR Figaro MDR Info MDR Jump MDR Sputnik Norddeutscher Rundfunk N-Joy NDR 2 NDR Info NDR Info Spezial NDR Kultur Südwestrundfunk DASDING SWR1 BW SWR1 RP SWR2 BW SWR2 RP SWR3 SWR Cont.Ra SWR4 BW SWR4 RP Westdeutscher Rundfunk COSMO (German radio station) WDR 2 WDR 3 WDR 4 WDR 5 1LIVE KIRAKA VeRa Radio BOB Radio Bremen Bremen Eins Bremen Zwei Bremen Vier Saarländischer Rundfunk SR 1 Europawelle Rundfunk Berlin-Brandenburg Antenne Brandenburg radioBERLIN 88,8 Inforadio Kulturradio Fritz radioeins Swiss Broadcasting Corporation Radio SRF 1 Radio SRF 2 Kultur Radio SRF Musikwelle Radio SRF Virus La Première (Switzerland) Option Musique Couleur 3 RSI Rete Uno Radiotelevisiun Svizra Rumantscha References External links SES - Official SES site SES fleet information Astra Digital Radio on the early Astra satellites SES S.A. Digital radio Satellite radio Telecommunications-related introductions in 1995 Audiovisual introductions in 1995 1995 establishments in Germany 1995 establishments in Luxembourg Products and services discontinued in 2012 2012 disestablishments in Germany 2012 disestablishments in Luxembourg

3836078

https://en.wikipedia.org/wiki/8P/Tuttle

8P/Tuttle

8P/Tuttle (also known as Tuttle's Comet or Comet Tuttle) is a periodic comet with a 13.6-year orbit. It fits the classical definition of a Jupiter-family comet with an orbital period of less than 20 years, but does not fit the modern definition of (2 < TJupiter< 3). Its last perihelion passage was 27 August 2021 when it had a solar elongation of 26 degrees at approximately apparent magnitude 9. Two weeks later, on September 12, 2021, it was about from Earth which is about as far from Earth as the comet can get when the comet is near perihelion. Comet 8P/Tuttle is responsible for the Ursid meteor shower in late December. 2008 perihelion Under dark skies, the comet was a naked-eye object. Perihelion was late January 2008 and, as of February, was visible telescopically to Southern Hemisphere observers in the constellation Eridanus. On December 30, 2007, it was in close conjunction with spiral galaxy M33. On January 1, 2008, it passed Earth at a distance of . Predictions that the 2007 Ursid meteor shower could have possibly been stronger than usual due to the return of the comet, did not appear to materialize, as counts were in the range of normal distribution. Contact binary Radar observations of Comet Tuttle in January 2008 by the Arecibo Observatory show it to be a contact binary. The comet nucleus is estimated at about 4.5 km in diameter, using the equivalent diameter of a sphere having a volume equal to the sum of a 3 km and 4 km sphere. Additional images References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 8P/Tuttle – Seiichi Yoshida @ aerith.net 8P at Kronk's Cometography 8P/Tuttle time sequence Comet Tuttle Seen To Be Returning Comet 8P/Tuttle. Canary Islands, Tenerife. 06.01.2008 NASA Orbital Diagram Periodic comets 0008 008P Meteor shower progenitors Contact binary (small Solar System body) 20210827 18580105

3837781

https://en.wikipedia.org/wiki/Comet%20Skorichenko%E2%80%93George

Comet Skorichenko–George

Comet Skorichenko–George (sometimes spelled Scorichenko–George) is also designated C/1989 Y1, 1990 VI, and 1989e1. It was discovered on December 17, 1989 by Doug George of Kanata (near Ottawa), Ontario, Canada, and Soviet astronomer Boris Skoritchenko (Mezmay, Krasnodar Krai). Skoritchenko was using 8×20 binoculars, whilst George was using a 16" reflector and had searched for 65 hours. The comet was magnitude 10.5 in the northern evening sky. It passed its perihelion on April 11, 1990 at a distant 1.57 AU, and remained in the Earth's evening sky through April 1990, at magnitude 9–10. C2 emission bands were observed in the comet Skorichenko-George. References External links Saguaro Astronomy Club News, #157, February 1990 Non-periodic comets 1989 in science 19891217

3840763

https://en.wikipedia.org/wiki/Christofilos%20effect

Christofilos effect

The Christofilos effect, sometimes known as the Argus effect, refers to the entrapment of electrons from nuclear weapons in the Earth's magnetic field. It was first predicted in 1957 by Nicholas Christofilos, who suggested the effect had defensive potential in a nuclear war, with so many beta particles becoming trapped that warheads flying through the region would experience huge electrical currents that would destroy their trigger electronics. The concept that a few friendly warheads could disrupt an enemy attack was so promising that a series of new nuclear tests was rushed into the US schedule before a testing moratorium came into effect in late 1958. These tests demonstrated that the effect was not nearly as strong as predicted, and not enough to damage a warhead. However, the effect is strong enough to be used to black out radar systems and disable satellites. Concept Electrons from nuclear explosions Among the types of energy released by a nuclear explosion are a large number of beta particles, or high energy electrons. These are primarily the result of beta decay within the debris from the fission portions of the bomb, which, in most designs, represents about 50% of the total yield. Because electrons are electrically charged, they induce electrical currents in surrounding atoms as they pass them at high speed. This causes the atoms to ionize while also causing the beta particles to slow down. In the lower atmosphere, this reaction is so powerful that the beta particles slow to thermal speeds within a few tens of meters at most. This is well within a typical nuclear explosion fireball, so the effect is too small to be seen. At high altitudes, the much less-dense atmosphere means the electrons are free to travel long distances. They have enough energy that they will not be recaptured by the proton that is created in the beta decay, so they can, in theory, last indefinitely. Mirror effect In 1951, as part of the first wave of research into fusion energy, University of California Radiation Laboratory at Livermore ("Livermore") researcher Richard F. Post introduced the magnetic mirror concept. The mirror is a deceptively simple device, consisting largely of a cylindrical vacuum chamber that holds the fusion fuel and an electromagnet wound around it to form a modified solenoid. A solenoid normally generates a linear magnetic field along the center of its axis, in this case down the middle of the vacuum chamber. When charged particles are placed in a magnetic field, they orbit around the field lines, which, in this case, stops them from moving sideways and hitting the walls of the chamber. In a normal solenoid, they would still be free to move along the lines and thus escape out the ends. Post's insight was to wind the electromagnet in such a way that the field was stronger at the ends than in the center of the chamber. As particles flow towards the ends, these stronger fields force the lines together, and the resulting curved field causes particles to "reflect" back, thus leading to the name mirror. In a perfect magnetic mirror, the particles of fuel would bounce back and forth, never reaching the ends nor touching the sides of the cylinder. However, even in theory, no mirror is perfect; there is always a population of particles with the right energy and trajectory that allow them to flow out of the ends through the "loss cone". This makes magnetic mirrors inherently leaky systems, although initial calculations suggested the rate of leakage was low enough that one could still use it to produce a fusion reactor. Christofilos effect The shape of the Earth's magnetic field, or geomagnetic field, is similar to that of a magnetic mirror. The field balloons outward over the equator, and then necks down as it approaches the poles. Such a field would thus reflect charged particles in the same fashion as Post's mirrors. This was not a new revelation; it was already long understood to be the underlying basis for the formation of aurora. In the case of the aurora, particles of the solar wind begin orbiting around the field lines, bouncing back and forth between the poles. With every pass, some of the particles leak past the mirror points and interact with the atmosphere, ionizing the air and causing the light. Electrons released by fission events are generally in the range of . Initially, these would be subject to mirroring high in the atmosphere, where they are unlikely to react with atmospheric atoms and might reflect back and forth for some time. When one considers a complete "orbit" from north pole to south and back again, the electrons naturally spend more time in the mirror regions because this is where they are slowing down and reversing. This leads to increased electron density at the mirror points. The magnetic field created by the moving electrons in this region interacts with the geomagnetic field in a way that causes the mirror points to be forced down into the atmosphere. Here, the electrons undergo more interactions as the density of the atmosphere increases rapidly. These interactions slow the electrons so they produce less magnetic field, resulting in an equilibrium point being reached in the upper atmosphere about in altitude. Using this as the average altitude as the basis for the air density calculation allowed the interaction rate with the atmosphere to be calculated. Running the numbers, it appeared that the average lifetime of an electron would be of the order of 2.8 days. Example As an illustration, Christofilos considered the explosion of a bomb. This would produce 10 fission events, which in turn produce four electrons per fission. For the mirror points being considered, almost any beta particle traveling roughly upward or downward would be captured, which he estimated to be about half of them, leaving 2×10 electrons trapped in the field. Because of the shape of the Earth's field, and the results of the right-hand rule, the electrons would drift eastward and eventually create a shell around the entire Earth. Assuming the electrons were evenly spread, a density of 0.2 electrons per cubic centimeter would be produced. Because the electrons are moving rapidly, any object within the field would be subjected to impacts of about 1.5×10 electrons per second per square centimeter. These impacts cause the electrons to slow down, which, through bremsstrahlung, releases radiation into the object. The rate of bremsstrahlung depends on the atomic weight, or Z, of the material. For an object with an average Z of 10, the resulting flux is about 100 roentgen/hour, compared to the median lethal dose of about 450. Christofilos noted that this would be a significant risk to space travelers and their electronic equipment. As reentry vehicles (RVs) from ICBMs approach their targets, they travel at about , or around . An RV traveling through the mirror layer, where the electrons are at their densest, would thus be in the midst of the electric field for about ten seconds. Because of a warhead's high speed, the apparent voltage spike would induce an enormous current in any of its metal components. This might be so high as to melt the airframe, but more realistically, could destroy the trigger or guidance mechanisms. The density of the field is greatest at the mirror points, of which there are always two for a given explosion, the so-called magnetic conjugates. The explosion can take place at either of these two points, and the magnetic field will cause them to concentrate at the other point as well. Christofilos noted that the conjugate point for most of the continental United States is in the South Pacific, far west of Chile, where such explosions would not be noticed. Thus, if one were to explode a series of such bombs in these locations, a massive radiation belt would form over the US, which might disable the warheads of a Soviet attack. Of additional interest to military planners was the possibility of using this effect as an offensive weapon. In the case of an attack by US forces on the Soviet Union, the southern conjugate locations are generally in the Indian Ocean, where they would not be seen by Soviet early warning radar. A series of explosions would cause a massive radar blackout over Russia, degrading its anti-ballistic missile (ABM) system without warning. Since these effects were expected to endure for up to five minutes, about the amount of time that a line-of-sight radar in Russia would have to see the warheads, careful timing of the attack could render the ABM system useless. History Background Christofilos began his career in physics while reading journal articles at an elevator company during the Axis occupation of Greece when he had little else to do. In the post-war era, he started an elevator repair service, during which time he began to develop the concept today known as strong focusing, a key development in the history of particle accelerators. In 1949, he sent a letter describing the idea to the Berkeley Lab but they rejected it after finding a minor error. In 1952, the idea was developed independently at the Brookhaven National Laboratory, which published on the topic. Convinced they had stolen the idea, Christofilos traveled to the US where he managed to win a job at Brookhaven. Christofilos soon became more interested in nuclear fusion efforts than particle accelerator design. At the time there were three primary designs being actively worked on in the US program, the magnetic mirror, the stellarator, and the z-pinch. The mirror was often viewed unfavorably due to its inherent leakiness, a side effect of its open field lines. Christofilos developed a new concept to address this problem, known as the Astron. This consisted of a mirror with an associated particle accelerator that injected electrons outside the traditional mirror area. Their rapid movement formed a second magnetic field which mixed with that of the electromagnet and caused the resulting net field to "close", fixing the mirror's biggest problem. Sputnik and Explorer During the same period, plans were being made by the US to test the presence of the expected charged layer directly using the Explorer 1 satellite as part of the International Geophysical Year (IGY). Before Explorer launched, the Soviets surprised everyone by launching Sputnik 1 in October 1957. This event caused near-panic in US defense circles, where many concluded the Soviets had achieved an insurmountable scientific lead. Among those worried about the Soviet advances was Christofilos, who published his idea in an internal memo that same month. When Explorer launched in January 1958, it confirmed the existence of what became known as the Van Allen radiation belts. This led to new panic within the defense establishment when some concluded that the Van Allen belts were not due to the Sun's particles, but secret Soviet high-altitude nuclear tests of the Christofilos concept. Planning begins Christofilos' idea immediately sparked intense interest; if the concept worked in practice, the US would have a "magic bullet" that might render the Soviet ICBM fleet useless. In February 1958, James Rhyne Killian, chairman of the recently formed President's Science Advisory Committee (PSAC), convened a working group at Livermore to explore the concept. The group agreed that the basic concept was sound, but many practical issues could only be solved by direct testing with explosions at high altitudes. By that time, planning for the 1958 nuclear testing series, Operation Hardtack I, was already nearing completion. This included several high-altitude explosions launched over the South Pacific testing range. As these were relatively close to the equator, the proper injection point for the magnetic field was at a relatively high altitude, far higher than the of Shot Teak. This would limit the usefulness of these explosions for testing the Christofilos effect. A new series of explosions to test the effect would be needed. Adding to the urgency of the planning process was the ongoing negotiations in Geneva between the US and the USSR to arrange what eventually became the Partial Nuclear Test Ban Treaty. At the time, it appeared that a test ban might come into place in the northern-hemisphere fall of 1958. The Soviets would react negatively if the US began high-altitude tests while negotiations were taking place. The planners were given the task of completing the tests by 1 September 1958. The launch of Sputnik also resulted in the formation of the Advanced Research Projects Agency (ARPA) in February 1958, initially with the mission of centralizing the various US missile development projects. Its charter was soon expanded to consider the topic of defense in general, especially defense against missile attack that Sputnik made clear was a real possibility. ARPA's scientific director, Herbert York, formed a blue-ribbon committee under the name "Project 137" to "identify problems not now receiving adequate attention". The twenty-two man committee of who's-who in the physics world was chaired by John Archibald Wheeler, who popularized the term black hole. York briefed President Eisenhower on the Christofilos concept and, on 6 March 1958, received a go-ahead to run a separate test series. Intense planning was carried out over the next two months. Christofilos did not have Q clearance and could not be part of the planning. The Project 137 group nevertheless arranged for Christofilos to meet with them at Fort McNair on 14 July 1958 for a discussion of the plans. Testing To achieve the September deadline, weapons and equipment would need to be drawn as much as possible from existing stocks. This resulted in the only suitable launcher being the Lockheed X-17, which was under production for reentry testing and was available in some quantity. Unfortunately, the X-17's limited altitude capability meant it could not reach the required altitude to hit mirror points in the South Pacific over the testing grounds. The only area that had a field low enough for the X-17 to hit easily was the South Atlantic Anomaly, where the Van Allen Belt descends as low as . Planning for tests normally took a year or more, which is why tests normally occurred in closely spaced "series". In contrast, Operation Argus tests went from initial approval by the President on 6 March 1958 to actual tests in only five months. Among other firsts, the tests were to be kept entirely secret from start to after completion, were the first ballistic missile tests from a ship at sea, and were the only atmospheric nuclear test operation in the Atlantic Ocean. The final plans were approved by the President on 1 May 1958. To measure the effect, Explorer IV and Explorer V were launched in August, although only IV reached orbit. Operation Argus was carried out in late August and early September 1958. Three low-yield atomic bombs were detonated over the south Atlantic at a height of . The bombs released charged particles that behaved exactly as Christofilos had predicted, being trapped along the lines of force. Those that managed to get far enough into the atmosphere to the north and south set up a small magnetic storm. Outcome These tests demonstrated that the possibility of using the effect as a defensive system did not work. However, exact details on the lack of effectiveness remain absent in available sources. Most references state that the effect did not last long enough to be useful, with an ARPA report concluding that it "dissipated rapidly" and would thus have little value as an anti-warhead system. However, other sources state that the effect persisted for over six days on the last test. Public release Late in June 1958, Hanson Baldwin, a Pulitzer Prize-winning military correspondent at The New York Times, received tantalizing hints of a major US military operation. It is now believed that this leaked from the University of Iowa lab run by James Van Allen, which was working with ARPA on Argus throughout this period. Baldwin asked his science reporter colleague Walter Sullivan (journalist) about the matter. Sullivan spoke to Richard Porter, chair of the IGY Panel on Rockets and Satellites, who was "horrified" by how much information Baldwin had found out. An hour later, Sullivan received a call from ARPA, asking him to hold the story until the tests were complete. By the end of the year, with the tests over and the concept largely abandoned, Christofilos was able to talk about the concept openly at an October 1958 meeting of the American Physical Society, leaving out only the detail that an atomic bomb would be used to create the radiation. At the December meeting of the American Association for the Advancement of Science, Sullivan heard that a paper on the topic, titled "Artificial Modification of the Earth's Radiation Belt", was being readied for publication. Sullivan and Baldwin realized they were about to lose their "scoop", so Sullivan wrote to York asking for clearance as it was clear other reporters were learning of the tests. York discussed the matter with James Killian, chair of the Presidents Science Advisory Committee (PSAC), who added that Van Allan was also pressing hard for publication rights. Sullivan later drove home his point about the information coming out anyway by calling the IGY monitoring stations and asking about records for aurora during August and September. He was told there was a "rather remarkable event" that did not correspond to any known solar storm. He sent another letter to York, noting that the hints about the project were already public and were simply waiting for someone to connect the dots. York called him to the Pentagon and asked him again to hold off. Sullivan concluded this was no longer due to military necessity but was political; the test ban negotiations were ongoing and the sudden release of news the US had performed new tests in space would be a serious problem. Sullivan and Baldwin once again sat on the story. In February 1959, Killian was in New York giving a speech. Sullivan attended and at the end handed him a letter. The two sat down and Killian read it. The letter outlined the fact that an increasing amount of information was leaking about the tests and that the Times had been patiently waiting on approval from the Pentagon that appeared not to be forthcoming. Meanwhile, scientists working on the project were becoming increasingly vocal about the publication of the data, and a late February meeting resulted in arguments. At a PSAC meeting, Killian finally agreed to release the data at the April meeting of the National Academy of Sciences, but still did not tell the Times. Baldwin and Sullivan had had enough; they went to the top of the Times hierarchy, publisher Arthur Hays Sulzberger, president Orvil E. Dryfoos, and managing editor Turner Catledge, who approved publication. On 18 March 1959, Sullivan tried to call Killian but reached his assistant instead, while Baldwin spoke with ARPA director Roy Johnson. The two wrote the story that night, waiting for the phone call that would again kill the story. The phone never rang and the story was published the next day. Ongoing concerns In 2008, science writer Mark Wolverton noted ongoing concerns about the use of the Christofilos effect as a way to disable satellites. See also Operation Argus Operation Fishbowl Outer Space Treaty Soviet Project K nuclear tests Starfish Prime Van Allen radiation belt List of artificial radiation belts Nicholas Christofilos Notes References Citations General references Astroparticle physics Exoatmospheric nuclear weapons testing Anti-ballistic weapons

3840912

https://en.wikipedia.org/wiki/Thunderstone%20%28folklore%29

Thunderstone (folklore)

A thunderstone is a prehistoric hand axe, stone tool, or fossil which was used as an amulet to protect a person or a building. The name derives from the ancient belief that the object was found at a place where lightning had struck. Thunderstone folklore European tradition Albanians believed in the supreme powers of thunderstones (kokrra e rrufesë or guri i rejës), which were believed to be formed during lightning strikes and to fall from the sky. Thunderstones were preserved in family life as important cult objects. It was believed that bringing them inside the house would bring good fortune, prosperity, and progress to people, especially in livestock and agriculture, or that rifle bullets would not hit the owners of thunderstones. Thunderstone pendants were believed to have protective powers against the negative effects of the evil eye and were used as talismans for both cattle and pregnant women. Classical world The Greeks and Romans, at least from the Hellenistic period onward, used Neolithic stone axeheads for the apotropaic protection of buildings. A 1985 survey of the use of prehistoric axes in Romano-British contexts found forty examples, of which twenty-nine were associated with buildings including villas, military structures such as barracks, temples, and kilns. Middle Ages During the Middle Ages many of these well-wrought stones were venerated as weapons, which during the "war in heaven" had been used in driving forth Satan and his hosts. Hence, in the 11th century the Byzantine emperor sent to the Holy Roman emperor a "heaven axe"; and in the 12th century, a Bishop of Rennes asserted the value of thunderstones as a divinely appointed means of securing success in battle, safety on the sea, security against thunder, and immunity from unpleasant dreams. European folklore In Scandinavia thunderstones were frequently worshiped as family gods who kept off spells and witchcraft. Beer was poured over them as an offering, and they were sometimes anointed with butter. In Switzerland the owner of a thunderstone whirls it, on the end of a thong, three times around his head, and throws it at the door of his dwelling at the approach of a storm to prevent lightning from striking the house. In Italy they are hung around children's necks to protect them from illness and to ward off the Evil eye. In Roman times, they were sewn inside dog collars along with a little piece of coral to keep the dogs from going mad. In Sweden they offer protection from elves. Up until the 19th century it was common practice in Limburg to sew thunderstones into cloth bags and carried over the chest, in the belief that it would soothe stomach ailments.   In some parts of Spain for example the province of Salamanca it was believed that by rubbing the thunderstones on the joints it would help prevent rheumatic diseases. In the French Alps they protect sheep, while elsewhere in France they are thought to ease childbirth. Among the Slavs they cure warts on man and beast, and during Passion Week they have the property to reveal hidden treasure. Asian tradition In Burma they are used as a cure and preventative for appendicitis. In Japan they cure boils and ulcers. In Malaysia and Sumatra they are used to sharpen the kris, are considered very lucky objects, and have been credited with being touchstones for gold. North American tradition In North Carolina and Alabama there is a belief that flint stones placed in the fire will keep hawks from molesting the chickens, a belief which probably stems from the European idea that elf arrows protect domestic animals. In Brazil, flint is used as a divining stone for gold, treasure and water. Native American folklore The flint was an object of veneration by most American Indian tribes. According to the Pawnee origin myth, stone weapons and implements were given to man by the Morning Star. Among the K'iche' people of Guatemala, there is a myth that a flint fell from the sky and broke into 1600 pieces, each of which became a god. Tohil, the god who gave them fire, is still represented as flint. This myth provides a parallel to the almost universal belief in the thunderstone, and is reminiscent of how the Roman god Jupiter was worshipped in the form of a flint stone. The Cherokee shaman invokes a flint when he is about to scarify a patient prior to applying his medicine. Among the Pueblos there were flint societies which, in most tribes, were primarily concerned with weather and witchcraft, but sometimes had to do with war and medicine. Fossils as thunderstones In many parts of southern England until the middle of the nineteenth century, another name commonly used for fossil Echinoids was 'thunderstone', though other fossils such as belemnites and (rarely) ammonites were also used for this purpose. In 1677 Dr. Robert Plot, the first keeper of the Ashmolean Museum in Oxford, published his classic book The Natural History of Oxfordshire. Plot recorded that in Oxfordshire what are now known as fossil echinoids were called thunderstones, as they were thought to have descended from the heavens during a thunderstorm. The St. Peter's Church in Linkenholt, England, was built in 1871 near the location of the old St. Peter's, which had stood for nearly 700 years. The 1871 version of the church included fossil echinoids built into the walls surrounding the windows, a style adopted from the original. This implies that Thunderstone folklore was retained for at least 700 years in England, and had its roots in pagan folklore. In Sussex in the early 20th century fossil echinoids were also used on the outside windowsills of kitchens and dairies to stop milk going off (because thunder was believed to be able to sour milk). Decline of thunderstone mythology Even as late as the 17th century, a French ambassador brought a stone hatchet, which still exists in the museum at Nancy, as a present to the Prince-Bishop of Verdun, and claimed that it had healing properties. Andrew Dickson White described the discovery of the true origin of thunderstones as a "line of observation and thought ... fatal to the theological view". In the last years of the sixteenth century Michael Mercati tried to prove that the "thunder-stones" were weapons or implements of early races of men; but for some reason his book was not published until the following century, when other thinkers had begun to take up the same idea. In 1723 Antoine de Jussieu addressed the French Academy on "The Origin and Uses of Thunder-stones". He showed that recent travelers from various parts of the world had brought a number of weapons and other implements of stone to France, and that they were essentially similar to what in Europe had been known as "thunderstones". A year later this fact was firmly embedded in the minds of French scientists by the Jesuit Joseph-Francois Lafitau, who published a work showing the similarity between the customs of aborigines then existing in other lands and those of the early inhabitants of Europe. So began, in these works of Jussieu and Lafitau, the science of ethnology. It was only after the French Revolution of 1830, more than a century later, that the political climate in Europe was free enough of religious sentiment for archaeological discoveries to be dispassionately investigated and the conclusion reached that human existence spanned a much greater period of time than any Christian theologian had dreamt of. Boucher de Perthes In 1847, a man previously unknown to the world at large, Boucher de Perthes, published in Paris the first volume of work on Celtic and Antediluvian Antiquities, and in this he showed engravings of typical flint implements and weapons, of which he had discovered thousands upon thousands in the high drift beds near Abbeville, in northern France. So far as France was concerned, he was met at first by what he calls "a conspiracy of silence", and then by a contemptuous opposition among orthodox scientists, led by Elie de Beaumont. In 1863 the thunderstone myth was further discredited by Charles Lyell in his book Geological Evidences of the Antiquity of Man. Lyell had previously opposed the new ideas about human antiquity, and his changing sides gave further force to the scientific evidence. See also Elfshot Elf-arrow Projectile point Arrowhead Stone tool Perkwunos References Amulets Folklore Forteana History of archaeology Rocks in religion Flint (rock) Axes Lithics Fossils

3841958

https://en.wikipedia.org/wiki/USNS%20Alan%20Shepard

USNS Alan Shepard

USNS Alan Shepard (T-AKE-3) is a Lewis and Clark-class dry cargo ship in the United States Navy. She is named for astronaut and Rear Admiral Alan Shepard (1923–1998), the first American in space and the fifth person to walk on the Moon. Service history The contract to build her was awarded to National Steel and Shipbuilding Company (NASSCO) of San Diego, on 16 July 2002. Construction began on 13 September 2005. She was launched on 6 December 2006, sponsored by Laura Churchley, daughter of RAdm. Shepard. Alan Shepard entered active service in 2007. She was initially part of the Pacific Fleet. During Exercise Pacific Vanguard in August 2022, Alan Shepard launched a BQM-177A target drone during live-fire practice with the guided-missile destroyer and the Australian frigate ; this was the first time the drone was used in a training exercise. Both vessels launched missiles at the BWM-177A and successfully intercepted it. By 2023, Alan Shepard was assigned to the United States Fifth Fleet. In July 2023, Alan Shepard entered a shipyard in Al Hidd, Bahrain, and on 15 July, while leaving the shipyard, she ran aground. None of the approximately 85 individuals on the ship were injured in the accident. The next day, tugboats refloated Alan Shepard. An inspection after the accident revealed that Alan Shepard was not significantly damaged. References External links Lewis and Clark-class dry cargo ships Ships built in San Diego 2006 ships Alan Shepard Bulk carriers of the United States Navy Maritime incidents in 2023

3844218

https://en.wikipedia.org/wiki/Sat%C3%A9lite%20de%20Coleta%20de%20Dados

Satélite de Coleta de Dados

Satélite de Coleta de Dados (SCD, Portuguese for "Data-Collecting Satellite") is a series of satellites developed in Brazil. SCD-1 The first one, SCD-1, was launched on February 9, 1993, and was the first satellite developed entirely in Brazil and it remains in operation in orbit to this date. SCD-1 was designed, developed, built, and tested by Brazilian scientists, engineers, and technicians working at National Institute of Space Research and in Brazilian industries. It was made to be launched with a Brazilian rocket in 1989. Once it was officially recognized that the rocket could not be completed until many years later, SCD-1, after undergoing minor adaptations, was finally launched with a Pegasus rocket made by Orbital Sciences. The rocket was launched from a B-52 airplane while flying over the Atlantic Ocean. SCD-1 is an experimental communication satellite with an environmental mission. It receives data collected on the ground or at sea by hundreds of automatic data-collecting platforms (DCPs) and retransmits all the information in a combined real-time signal back to tracking stations on Earth. Applications include hydrology, meteorology, and monitoring of the environment in general. The data are used by agencies such as the Weather Forecasting and Climate Studies Center (Centro de Previsão do Tempo e Estudos Climáticos—CPTEC), hydroelectric power managers, and both private and governmental institutions with many different interests. An example is meteorological and environmental data collected in the Amazon region, including the levels of carbon monoxide and carbon dioxide in the atmosphere. These data are transmitted to INPE and are used for monitoring forest fires. SCD-1 weighs approximately 110 kg and goes around the Earth every 100 minutes on a nearly circular orbit at about 760 km altitude. The inclination of the orbit with respect to the plane of the equator is 25 degrees, providing excellent coverage of equatorial, tropical, and subtropical regions (up to about 35 degrees of latitude) around the world. The spin-stabilized spacecraft has the shape of an octagonal prism, with a diameter of 1 meter and a height near 70 cm without the antennas that are mounted on both base surfaces. It was originally designed for a life of one year with 80% probability, but it has survived 30 years in operation (as of 2023) without any crippling functional failure. However, since its chemical (nickel-cadmium) batteries are now completely run down, the satellite can no longer be used while it is in the Earth's shadow. After the buzz of the New Horizons spacecraft flyby of NASA in July 2015, revealing feature and characteristics on Pluto, the International Astronomical Union (IAU) will scan an area on the surface of Pluto, which possibly will be named after the Sátelite Coleta de Dados (SCD-1), as “Coleta de Dados”, located in the large Tombaugh Regio, inside the area Sputnik Planitia. More than thirty companies were involved in the production of the SCD-1, with INPE itself providing much of the electronics. SCD-2A SCD-2A (Satélite de Coleta de Dados 2A in Portuguese) was a fully planned, constructed and qualified Brazilian data collection satellite in Brazil. SCD-2A was identical to SCD-2, which was successfully launched in 1998. SCD-2A was lost in the inaugural launch of the Brazilian rocket VLS-1 in 1997. The SCD-2A was launched into space on November 2, 1997, by means of a VLS-1 rocket from the Alcântara Launch Center in state of Maranhão, Brazil. It had a mass of 115 kilograms. However, the satellite was lost due to an ignition failure in one of the first-stage thrusters during the first few seconds of flight, requiring the activation of the vehicle's self-destruct command. SCD-2 SCD-2 has the function to collect the environmental data to be later picked up by tracer stations and be distributed to organizations and to various users. SCD-2 was launched on October 23, 1998, by a Pegasus rocket, that was transported under the wing of a Lockheed L-1011 Tristar, that launched it from 13 km altitude. It is the second satellite of MECB - Complete Brazilian Space Mission - program developed by INPE. Its solar panels were built with technology developed in Rio Grande do Sul, Brazil, in partnership with the project team of the satellite's power subsystem by INPE. On its 10th birthday, on 23 October 2008, SCD-2 had completed 52,807 orbits around the Earth. Within a decade, it had covered a distance of 2,365,088,861 kilometers, which corresponds to 3,112 times round trips to the moon and back (distance between Earth and the Moon: approximately 236,000 miles). SCD-2 has now more than doubled these figures, having completed its second decade of successful operation in orbit. See also CBERS References External links Satellite page on Globalsecurity.org Satélite de Coleta de Dados SCD-1 Communications satellites of Brazil Data collection satellites Spacecraft launched in 1993 Spacecraft launched in 1998 Spacecraft launched by Pegasus rockets Satellite series pt:Satélite de Coleta de Dados 1

3845343

https://en.wikipedia.org/wiki/Lagina

Lagina

Lagina () or Laginia (Λαγινία) was a town and religious centre in ancient Caria. It contained an important monumental temple of Hecate, at which great festivals were celebrated every year. For most of antiquity, it was a part of the territory of Stratonicea. Its site is located near Turgut, Anatolia, in southwestern Turkey. History Recent studies have shown that the site had been inhabited and/or employed in an uninterrupted manner during a time span stretching back to the Bronze Age. Little is known about the early history of Lagina as a town and religious sanctuary, although it existed as early as the 4th century BCE. At that time, Lagina was a deme of nearby Koranza. Unlike the sanctuaries at Sinuri or Labraunda, Lagina does not appear to have been favoured by the Hecatomnids. Lagina became one of the major rural cult centres of the polis of Stratonicea. Stratonicea was a large Seleucid colony in Caria, settled by Macedonians and local Carians, in the mid-3rd century BCE. Every year, Stratoniceans would go on pilgrimage to the temple of Hecate at Lagina and of Zeus at Panamara. When Tacitus spoke of the worship of Trivia among the Stratoniceans, he evidently meant Hecate. The goddess Hecate was so important to Stratonicea that her likeness appeared on coins of the independent city after 167/166 BCE. Seleucid kings conducted a considerable construction effort in the sacred ground of Lagina and transformed it into a foremost religious center of its time. Lagina and Stratonicea were connected to each other by a 'sacred path' 11 kilometers long, along which pilgrims could process. The close association between Lagina and Stratonicea continued after the Seleucids lost control of Caria. In 188 BCE, the Treaty of Apamea gave governance of Caria to Rhodes, an ally of the Roman Republic during the Roman–Seleucid war. An inscription from this time shows that the head priest of Hecate was also appointed local priest of the Rhodian sun-god Helios, by decree of Stratonicea. Alongside the rest of Caria, Lagina and Stratonicea became part of the Roman province of Asia by the end of the 2nd century BCE. The Roman period saw the most elaborate temple of Hekate build at Lagina. Although it was previously thought that the temple was constructed in the aftermath of the First Mithridatic War (i.e. late 80s BCE), it is now understood to have been built earlier, before the war against Eumenes III Aristonikos in 133 BCE. The temple is considered the last great monument of the so-called 'Ionian Renaissance', which began in Hecatomnid Caria with monuments like the Mausoleum of Halicarnassus. Monumental construction continued under the Roman Empire. The emperor Augustus himself donated a significant amount to help the site recover from damage after Lagina was attacked by Quintus Labienus, a rebel with Parthian support, in 40 BCE. In particular, a new altar was built. Lagina continued to thrive until a catastrophic earthquake in 365 BCE. After that date, all stoai fell out of use and the central altar was cracked. A large basilica was subsequently built between the altar and the temple, and used from the 4th to the 6th centuries CE. Lagina was Christianised at an early date and was the seat of a bishop; no longer a residential see, it remains a titular see of the Roman Catholic Church. Worship of Hecate Lagina was the largest site of a monumental temple to Hecate. The rituals carried out at Lagina were therefore unique. Hecate was a goddess of ancient Greek mythology whose roots were probably Carian and Anatolian. Her general attributes included torches, keys, and dogs, and today she is often associated with witchcraft. Part of these rituals included a "Key-Carrying" ceremony in which a choir of young girls would walk from Lagina to Stratonicea to declare their devotion to the city. On their return, the gates would be opened by the girl carrying the key (the kleidophoros), and the religious festivities would begin. This ritual not only served as a political reminder that Stratonicea controlled Lagina, but also that Hecate controlled the keys to the underworld. Excavations The site of Lagina was often visited by travellers in the eighteenth and nineteenth centuries. The British archaeologist Charles Thomas Newton found over thirty inscriptions and nine decorated frieze blocks at the site in 1856. His publications brought European scholarly attention to Lagina. Authorised excavations began at Lagina in 1891 under the direction of Osman Hamdi Bey. The archaeological research conducted in Lagina is historically significant in that it was the first authorised excavation to have been done by a Turkish scientific team. In 1993, excavation and restoration work was resumed under the guidance of the Muğla Museum, by an international team advised by Professor Ahmet Tırpan. In 2020, the ancient columns of the Hecate temple were re-erected following extensive restoration and excavation at the site. The head of excavation at the temple, Professor Bilal Sögüt, noted that visitors could now see where the columns would have stood 2050 years ago when the temple was a place of worship to the goddess Hecate. The columns were built in the Corinthian order, with 8 columns on the shorter sides of the temple, and 11 on the longer sides. An inscription on the entrance gate indicate that Emperor Augustus financially supported the Sanctuary of Hecate. The friezes of the Hecate sanctuary are displayed in the Istanbul Archaeology Museums. Four different themes are depicted in these friezes. These are, on the eastern frieze, scenes from the life of Zeus; on the western frieze, a battle between gods and giants; on the southern frieze, a gathering of Carian gods; and on the northern frieze, a battle of Amazons. References Ancient Greek archaeological sites in Turkey Populated places in ancient Caria Seleucid colonies in Anatolia Catholic titular sees in Asia Archaeological sites in the Aegean Region Holy cities Yatağan District History of Muğla Province Hecate

3846760

https://en.wikipedia.org/wiki/Tagish%20Lake%20%28meteorite%29

Tagish Lake (meteorite)

The Tagish Lake meteorite fell at 16:43 UTC on 18 January 2000 in the Tagish Lake area in northwestern British Columbia, Canada. History Fragments of the Tagish Lake meteorite landed upon the Earth on January 18, 2000, at 16:43 UT (08:43 local time in Yukon) after a large meteoroid exploded in the upper atmosphere at altitudes of with an estimated total energy release of about 1.7 kilotons of TNT. Following the reported sighting of a fireball in southern Yukon and northern British Columbia, Canada, more than 500 fragments of the meteorite were collected from the lake's frozen surface. Post-event atmospheric photographs of the trail left by the associated fireball and U.S. Department of Defense satellite information yielded the meteor trajectory. Most of the stony, carbonaceous fragments landed on the Taku Arm of the lake, coming to rest on the lake's frozen surface. The passage of the fireball and the high-altitude explosion set off a wide array of satellite sensors as well as seismographs. The local inhabitants described the smell in the air following the airburst as sulfurous and many first thought the blast was caused by a missile. Meteoroid The Tagish Lake meteoroid is estimated to have been 4 meters in diameter and 56 tonnes in weight before it entered the Earth's atmosphere. However, it is estimated that only 1.3 tonnes remained after ablation in the upper atmosphere and several fragmentation events, meaning that around 97% of the meteorite had vaporised, mainly becoming stratospheric dust that was seen as noctilucent clouds to the northwest of Edmonton at sunset, some 12 hours after the event. Of the 1.3 tonnes of fragmented rock, somewhat over (about 1%) was found and collected. Specimens Tagish Lake is classified as a carbonaceous chondrite, type C2 ungrouped. The pieces of the Tagish Lake meteorite are dark grey to almost black in color with small light-colored inclusions, and a maximum size of ~2.3 kg. Except for a greyish fusion crust, the meteorites have the visual appearance of a charcoal briquette. The fragments were transported in their frozen state to research facilities after they were collected by a local resident in late January, 2000. Initial studies of these fresh fragments were done in collaboration with researchers from NASA. Snowfall covered the remaining fragments until April 2000, when a search effort was mounted by researchers from the University of Calgary and University of Western Ontario. These later fragments were mostly found to have sunk into the ice by a few cm to more than 20 cm, and had to be collected out of meltwater holes, or cut in icy blocks from the frozen surface of Tagish Lake. Fragments of the fresh, "pristine" Tagish Lake meteorite totaling more than 850 g are currently held in the collections at the Royal Ontario Museum and the University of Alberta. "Degraded" fragments from the April–May 2000 search are curated mainly at the University of Calgary and the University of Western Ontario. Analysis and classification Analyses have shown that Tagish Lake fragments are of a primitive type, containing unchanged stellar dust granules that may have been part of the cloud of material that created the Solar System and Sun. This meteorite shows some similarities to the two most primitive carbonaceous chondrite types, the CI and CM chondrites; it is nevertheless quite distinct from either of them. Tagish Lake has a much lower density than any other type of chondrite and is actually composed of two somewhat different rock types. The major difference between the two lithologies is in the abundance of carbonate minerals; one is poor in carbonates and the other is rich in them. The meteorite contains an abundance of organic materials, including amino acids. The organics in the meteorite may have originally formed in the interstellar medium and/or the solar protoplanetary disk, but were subsequently modified in the meteorites' asteroidal parent bodies. A portion of the carbon in the Tagish Lake meteorite is contained in what are called nanodiamonds—very tiny diamond grains at most only a few micrometers in size. In fact, Tagish Lake contains more of the nanodiamonds than any other meteorite. As with many carbonaceous chondrites, and Type 2 specimens in particular, Tagish Lake contains water. The meteorite contains water-bearing serpentinite and saponite phyllosilicates; gypsum has been found, but may be weathering of meteoritic sulfides. The water is not Earthly contamination but isotopically different from terrestrial water. The age of the meteorite is estimated to be about 4.55 billion years thus being a remainder of the period when the solar system was formed. Origin Based on eyewitness accounts of the fireball caused by the incoming meteor and on the calibrated photographs of the track which it had left behind and which was visible for about half an hour, scientists have managed to calculate the orbit it followed before it impacted with Earth. Although none of the photographs captured the fireball directly, the fireball path was reconstructed from two calibrated photos taken minutes after the event, giving the entry angle. Eyewitness accounts in the vicinity of Whitehorse, Yukon accurately constrained the ground track azimuth from either side. It was found that the Tagish Lake meteorite had a pre-entry Apollo type orbit that brought it from the outer reaches of the asteroid belt. Currently, there are only eleven meteorite falls with accurately determined pre-entry orbits, based on photographs or video recordings of the fireballs themselves taken from two or more different angles. Further study of the reflectance spectrum of the meteorite indicate that it most likely originated from 773 Irmintraud, a D-type asteroid. Comparisons The double, and not the expected single, plume formation of debris, as seen in video and photographs of the 2013 Chelyabinsk meteor dust trail and believed by Peter Brown to have coincided near the primary airburst location, was also pictured following the Tagish Lake fireball, and according to Brown, likely indicates where rising air quickly flowed into the center of the trail, essentially in the same manner as a moving 3D version of a mushroom cloud. See also Glossary of meteoritics 773 Irmintraud, the asteroid that the Tagish Lake meteorite most likely came from. References Universe: The Definitive Visual Dictionary, Robert Dinwiddie, DK Adult Publishing, (2005), pg. 222. Mittlefehldt, D.W., (2002), Geochemistry of the ungrouped carbonaceous chondrite Tagish Lake, the anomalous CM chondrite Bells, and comparison with CI and CM chondrites, Meteoritics and Planetary Science 37: 703–712. See summary of the article. External links Evidence of sodium rich alkaline water in the Tagish Lake parent body and implications for amino acid synthesis and racemization Tagish Lake meteorite contains clues as to how life may have arisen on Earth Tagish Lake meteorite may have held early forms of life, believe scientists Ancient rock star finds a home at the University of Alberta Researchers' website The Geological Society; Article/Analysis Brief Abstract Tagish Lake meteorite specimen pictures Meteorites found in Canada Planetary science Geography of British Columbia Geography of Yukon Natural history of British Columbia Natural history of Yukon 2000 in British Columbia 2000 in science Collections of the Royal Ontario Museum

3847627

https://en.wikipedia.org/wiki/Coat%20of%20arms%20of%20New%20South%20Wales

Coat of arms of New South Wales

The coat of arms of New South Wales is the official coat of arms of the Australian state of New South Wales. It was granted by royal warrant of King Edward VII dated 11 October 1906. Description The shield shows a blue (azure) field with a silver (argent) cross voided red (gules) with a gold (or) star on each arm of the red cross and a gold (or) lion in the centre known as the 'Lion in the South'. There is a golden fleece in the first and fourth quarters, and a wheat sheaf in the second and third quarters, both of these charges being gold (or), with the golden fleece having a band or ribbon around it coloured silver (argent). The crest is a rising sun with each of the sun's rays tipped with a little reddish-orange flame, on a wreath or torse of blue (azure) and silver (argent). The supporters are a golden (or) lion on the dexter (viewer's left) and a golden (or) kangaroo on the sinister (viewer's right). The supporters are usually depicted standing upon the motto ribbon as they hold the shield in an upright position. The motto contains the Latin inscription "Orta recens quam pura nites" which, in English, means "Newly risen, how brightly you shine". The official blazon, or heraldic description, is contained in the royal warrant, and reads: Azure a cross argent voided gules charged in the centre chief point with a lion passant guardant, and on each member with a mullet of eight points or between in the first and fourth quarters a fleece or banded argent and in the second and third quarters a garb also or: And for a crest, on a wreath of the colours a rising sun each ray tagged with a flame of fire proper: And for the supporters, on the dexter side a lion rampant guardant: And on the sinister side a kangaroo both or, together with this motto, "Orta Recens Quam Pura Nites," . Symbolism The blue field and white cross are derived from the earliest Australian coats of arms which show the Southern Cross that is visible in the skies of the southern hemisphere. The designer of the Arms 'voided' the white cross by laying a red cross within it, representing the red cross of St George as used on the ensign of Britain's Royal Navy, and placing a golden, 8-pointed star on each arm of the cross. This symbolises the maritime origins of NSW, with seafarers relying upon the Southern Cross to navigate the seas, and the role of the navy in protecting the State. The 'Lion in the South' is taken from the three golden lions on a red field on the arms of England, and symbolises both the sovereignty of NSW and the offspring of an old country. It represent the origins of the founders of the Colony of New South Wales as well as the independence of their succeeding generations. The Golden Fleece contains several layers of allusion: the wealth of NSW derived from its pastoral industries, especially wool; ideas of honour and chivalry in the Order of the Golden Fleece, the origins of New South Wales' merino flocks being in a gift from the King of Spain, commander of the Order, to William III; and to the heroic search by Jason and the Argonauts in their quest for the golden fleece. The wheatsheaf, or garb, also contains several layers of allusion: to the agricultural wealth of New South Wales, especially wheat growing; and to the convicts, many of whom, through their toil in producing food for the early colony, were rewarded with grants of land upon which they established the farms and rural landscapes of eastern New South Wales. These allusions were clear to educated men and women at the time, and those with an interest in the political economy of New South Wales at the turn of the 20th century. The rising sun in the crest has been used in the heraldry of New South Wales since the 1820s, essentially to symbolise hope in the future. It also depicts the geographical position of New South Wales, which faces the sun rising every morning over the Pacific Ocean. The blue and white wreath or torse shows the two principal colours in the shield, which are often used as the sporting colours for New South Wales, although there is much variation in the shade of the blue in common use. Of the two supporters, the lion symbolises the origins of many of the people of New South Wales in the early 20th century in the British Isles. The designer particularly stressed that this was not an English nor Scottish nor Irish nor Welsh lion, but British, to represent the coming together of many different people in a new land and forming a new people. It could today be understood as symbolising the multicultural nature of contemporary New South Wales society. The kangaroo has been used as a supporter in popular New South Wales heraldic practice since 1806, although this is its earliest official use. It symbolises the land and natural resources of the State, and can also be understood today as representing the Aboriginal peoples who today are an integral part of New South Wales society. The motto was first devised in 1879 for the International Exposition held in Sydney, and was adopted as the State motto in 1906 to clearly replace an older motto on official seals that referred to the State's convict origins. This motto reinforced the positive symbolism of the Arms with its message of hope in the future. Designer The Coat of Arms was designed by the NSW Government Printer, William Applegate Gullick, who had arrived in the colony as an infant with his parents. His father worked in the printing industry, and Gullick later served an apprenticeship in the printing trades with John Sands & Co, the colony's leading printers and stationers. He was appointed Government Printer in 1896, and was responsible for New South Wales postage stamp designs until 1913. Gullick was commissioned by Premier Carruthers in 1905 to design the Arms, and after some negotiation with the College of Arms in London he produced the design that was finally granted by the King. Gullick also had a role in the design of the Australian Coat of Arms. Legal status and use The State Arms are described in section 4(4) of the State Arms, Symbols and Emblems Act 2004 (see below) as the Arms of Dominion and Sovereignty of the State. Arms of Dominion and Sovereignty are the symbols of intangible public authority which belong to independent states and are used by their representatives (such as government agencies) and leaders. The royal warrant granting the Arms states that they are "...for the greater honour and distinction of Our State of New South Wales ...to be borne by the said State on Seals, Shields, Banners, Flags and otherwise according to the Laws of Arms." These laws are derived from medieval English civil law, and relate to the authority to grant Arms, and the regulation of their use, although the enforceability of these laws in New South Wales is unclear. The publication of the royal warrant in the NSW Government Gazette on 22 February 1907 confirmed their status as the official Arms of the State of New South Wales. The making of unauthorised copies of the Arms was prohibited by section 3 of the Unauthorised Documents Act 1922, and this remained the only piece of heraldic legislation in New South Wales until 2004. Although the State government made various attempts to use the Arms in a uniform manner, and despite the clear direction in the royal warrant about their use, there was wide variation in their use and uncertainty about their status. This was most notable in the courts, where the Royal Arms continued to be used to show the separation of executive and judicial powers. In 2003, the NSW Parliament passed the State Arms, Symbols and Emblems Act 2004, which patriated the Law of Arms to some degree regarding the Arms of the State. The Act definitively established the NSW Coat of Arms, to be known as the State Arms, as the Arms of the State of New South Wales, and required the use of the Arms wherever the authority of the State of New South Wales, or of the Crown in Right of NSW, is being represented. The Royal Arms, henceforth to be known as the UK Royal Arms, are no longer to be used for this purpose, and there was subsequently a programme of replacing the UK Royal Arms with the State Arms in public buildings, places, seals and documents. The Act provides an exemption from such replacement when a representation of the UK Royal Arms (such as a stone carving of the facade of a courthouse) is considered by the Heritage Council of NSW to contribute to the cultural significance of a heritage listed building. Future developments The State Arms, Symbols and Emblems Act specifically provides for the Arms to be further 'ornamented', and it is possible that 'ornamented' versions of the State Arms could be prepared in the future to reflect the separation of executive, judicial and legislative functions, reminiscent of the manner in which the UK Royal Arms were used by the courts prior to 2004. See also Flag of New South Wales Government of New South Wales Coat of arms of Sydney Australian heraldry References Bibliography Gullick, William Applegate, The New South Wales Coat of Arms, with notes on the earlier seals, Government Printer, Sydney 1907. Gullick, William Applegate, The Seals of New South Wales, Government Printer, Sydney 1914. Legislative Council, Report on the Proposed State Arms Bill, NSW Parliament, Legislative Council Standing Committee on Law and Justice, Report 23, Sydney December 2002. 'Royal Warrant Granting Armorial Ensigns and Supporters for the State of NSW', Government Gazette, Supplement, Sydney 22 February 1907: 1345-1346. External links About the Coat of arms on the NSW Premier's website Online Exhibition commemorating the Centenary of the NSW Coat of Arms 1906-2006 Archives in Brief: The NSW Coat of Arms and related records NSW Heritage Office: Heraldry Report on the Proposed State Arms Bill, Legislative Council, 2002 New South Wales New South Wales New South Wales New South Wales New South Wales New South Wales New South Wales New South Wales New South Wales

3853170

https://en.wikipedia.org/wiki/10P/Tempel

10P/Tempel

10P/Tempel, also known as Tempel 2, is a periodic Jupiter-family comet with a 5 year orbital period. It was discovered on July 4, 1873 by Wilhelm Tempel. The next perihelion passage is 2 August 2026 when the comet will have a solar elongation of 164 degrees at approximately apparent magnitude 8. Closest approach to Earth will be one day later on 3 August 2026 at a distance of . The comet nucleus is estimated to be roughly the size of Halley's Comet at 10.6 kilometers in diameter with a low albedo of 0.022. The nucleus is dark because hydrocarbons on the surface have been converted to a dark, tar like substance by solar ultraviolet radiation. The nucleus is large enough that even near aphelion (furthest distance from the Sun which is near the orbit of Jupiter) the comet remains brighter than about magnitude 21. During the 2010 apparition the comet brightened to about apparent magnitude 8. The most favorable apparition of 10P/Tempel 2 was in 1925 when it came within of Earth with an apparent magnitude of 6.5. Proposed exploration The Jet Propulsion Laboratory proposed a flyby of the comet with a flight spare of Mariner 4. The probe was instead used for a Venus flyby as Mariner 5. References External links Orbital simulation from JPL (Java) / Horizons Ephemeris Elements and Ephemeris for 10P/Tempel – Minor Planet Center 10P/Tempel 2 / 2010 – Seiichi Yoshida @ aerith.net 10P/Tempel 2 (2010) (astrosurf) Periodic comets 0010 Comets in 2015 20210324 18730704

3853503

https://en.wikipedia.org/wiki/28P/Neujmin

28P/Neujmin

28P/Neujmin, also known as Neujmin 1, is a large periodic comet in the Solar System. With a perihelion distance (closest approach to the Sun) of 1.5AU, this comet does not make close approaches to the Earth. The comet nucleus is estimated to be 21.4 kilometers in diameter with a low albedo of 0.025. Since 28P has such a large nucleus, it became brighter than the 20th magnitude in early 2019, roughly 2 years before coming to perihelion. When it came to opposition in May 2020, when it was still 3.5 AU from the Sun, it had an apparent magnitude around 16.9. But during the 2021 perihelion passage the comet was on the opposite side of the Sun as the Earth. The comet is not known for bright outbursts of activity. References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 28P at Kronk's Cometography 28P/Neujmin 1 – Seiichi Yoshida @ aerith.net Periodic comets 0028 19130903

3854080

https://en.wikipedia.org/wiki/31P/Schwassmann%E2%80%93Wachmann

31P/Schwassmann–Wachmann

31P/Schwassmann–Wachmann, also known as Schwassmann–Wachmann 2, is a periodic comet in the Solar System. It was discovered on January 17, 1929, at an apparent magnitude of 11. The comet has been seen at every apparition. The comet nucleus is estimated to be 6.2 kilometers in diameter. In 1929, the astronomer Anne Sewell Young identified the comet with an object that had been misidentified as the minor planet "Adelaide" (A904 EB). References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 31P at Kazuo Kinoshita's Comets 31P/Schwassmann-Wachmann 2 – Seiichi Yoshida @ aerith.net Periodic comets 0031 19290117

3854146

https://en.wikipedia.org/wiki/36P/Whipple

36P/Whipple

36P/Whipple is a periodic comet in the Solar System. It is the lowest numbered Quasi-Hilda comet. It passed from Jupiter in June 1922. The comet nucleus is estimated to be 4.5 kilometers in diameter. References External links 36P at Kronk's Cometography 36P/Whipple – Seiichi Yoshida @ aerith.net Periodic comets 0036 Comets in 2011 19331015 Discoveries by Fred Lawrence Whipple

3854198

https://en.wikipedia.org/wiki/37P/Forbes

37P/Forbes

37P/Forbes is a periodic comet in the Solar System. It was discovered on August 1, 1929, by Alexander F. I. Forbes in South Africa. The comet nucleus is estimated to be 1.9 kilometers in diameter. References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 37P/Forbes – Seiichi Yoshida @ aerith.net 37P at Kronk's Cometography 37P/Forbes 2011 05 29, 2:55:09 UT; mag 18.0 N; C. Bell H47 Periodic comets 0037 Comets in 2011 Comets in 2018 19290801

3854284

https://en.wikipedia.org/wiki/39P/Oterma

39P/Oterma

39P/Oterma is a currently inactive periodic comet with an orbital period of nearly 20 years that stays outside the orbit of Jupiter. The nucleus has a diameter around 4–5 km. It was last observed in August 2021 and came to perihelion in July 2023 while 1.2 AU from Jupiter. It will finish the modest approach to Jupiter in January 2025 and will next come to perihelion in July 2042 at distance of 5.9 AU from the Sun. Opposition will occur on 11 November 2023. Discovery The comet was discovered by Liisi Oterma at Turku University Observatory, Finland on a photo plate on 8 April 1943 as a faint object of 15th magnitude in the constellation of Virgo. Its orbit was calculated by L. E. Cunningham and R. N. Thomas who derived an orbit with a small eccentricity, a perihelion distance of 3.4 AU (i.e. a little outside the main asteroid belt) and an orbital period of 7.9 years. The comet was continuously observed till after its next perihelia of 1950 and 1958, however a close approach (0.095 AU/14.2 Mio. km) to Jupiter on 12 April 1963 put it on its current inactive centaur orbit where it will not become much brighter than 22nd magnitude for a long while. Nevertheless, it was recovered on 13 August 2001 on CCD images taken with the University of Hawaii 2.2 m reflector at Mauna Kea. Orbit Comet 39P/Oterma currently has a centaur-like orbit contained between Jupiter and Saturn. Since the orbit is outside the frost line which is located around 3 AU from the Sun, the comet does not approach the Sun closely and is mostly an inactive comet only brightening to about apparent magnitude 22. It is classified as a Chiron-type comet with TJupiter > 3; a > aJupiter. The eccentricity of its orbit is moderate and its inclination is only a little slanted with respect to the ecliptic which allows the orbit to be perturbed by Jupiter and Saturn. Orbital development Comet 39P/Oterma is an object with a rather unstable orbit in the long run because at irregular time intervals it undergoes very close approaches to the giant planets Jupiter and Saturn that severely influence and alter its orbit. This is also the reason why no definite statements can be made concerning the long-time development of its orbital characteristics for a period of more than a couple of hundred years in the past or in the future. Apart from relatively precise statements for a few hundred years around our epoch, further conclusions can only be drawn by the use of statistical methods. By means of the software SOLEX 11.0 by A. Vitagliano and based on the values of the currently best known orbital elements of 39P/Oterma and their uncertainties from the JPL Small Body Database, a set of 400 clones of the “mean” comet with randomly Gaussian distributed orbital elements (using their mean values and their sigma-values) was created and the orbital development of this bundle of objects with nearly identical orbits at the start epoch was calculated back in the past and forth in the future (neglecting non-gravitational effects). The result of these statistical calculations is presented in the following paragraphs. Not much can be said about the orbit of 39P/Oterma before the 19th century. It could have been anywhere either inside the orbit of Jupiter (least probable), between the orbits of Jupiter and Saturn (most probable), or even a Saturn-crossing one. Anyhow, even if it had not been there before, with a probability of 20% a close encounter (< 2 AU) with Jupiter happened between 1815 and 1817 which brought the orbit of 39P/Oterma for a longer period in a defined orbit. Thus at least from the beginning of the 19th century till 1937 the comet's orbit was framed by Saturn's orbit on the outside and Jupiter's orbit in the inside. That means, 39P/Oterma was at this period a centaur-like object as it is today with no chance of being observed from Earth. Following a closer approach to Jupiter (1.44 AU/215.6 Mio. km) on 27 March 1903, however, the comet's orbit was slightly perturbed so that its next approach to Jupiter on 27 October 1937 became an extremely close one like it probably had not happened for many centuries before. On this day, the comet approached Jupiter to only 0.165 AU/24.7 Mio km and this had very peculiar consequences. Already since the beginning of 1935, the comet was moving in an orbit nearly identical to Jupiter's with nearly the same angular velocity as the giant planet, i.e. 39P/Oterma underwent a temporary satellite capture (TSC) by Jupiter. However, this comet flew through the region near Jupiter over a rather short time, during which the comet did not complete a full revolution orbiting about the planet, instead already in the beginning of 1939 the comet could escape the planet's attraction. However, the close encounter with Jupiter had altered the comet's orbital parameters severely. The semi-major axis was reduced from 6.9 to 4.0 AU, as the aphelion distance decreased from 8.0 to 4.5 AU, and the perihelion distance from 5.8 to 3.4 AU. Consequently, the comet's orbit had become transformed from a centaur-like orbit to one that completely lay inside the orbit of Jupiter. As the comet was now much closer to the Sun, it became active and its increased brightness combined with a closer distance from Earth gave rise to its discovery in 1943, five months after having passed its perihelion. As the revolution period was reduced from a little more than 18 years to 7.9 years, it was now in an exact 3:2 mean motion resonance with Jupiter. Such a Jupiter-family comet is called a “quasi-Hilda comet” (QHC) and consequently after three revolutions the comet met again with the planet. From mid-1961 till the end of 1965 the comet again went through a temporary satellite capture (TSC) by Jupiter, while on 12 April 1963 an even closer approach to the planet at a distance of only 0.095 AU/14.2 Mio km occurred. This lead again to a transformation of the comet's orbit to an inactive centaur orbit with semi-major axis 7.2 AU, eccentricity 0.24, aphelion distance 9.0 AU, and perihelion distance 5.5 AU. The period of revolution became increased to 19.5 years. This is the current situation since the 1983 perihelion passage. And this will remain alike for quite a while. Although a couple of closer approaches to Saturn (1.015 AU on 3 June 2011 and 1.93 AU around 3 October 2168) and Jupiter (0.889 AU on 15 January 2025, 0.771 AU on 21 February 2155, and 1.17 ± 0.03 AU in May–July 2214) are going to happen, the orbit of 39P/Oterma keeps its overall characteristics at least until the beginning of the 24th century: The semi-major axis will stay in the span of 7.0 to 7.8 AU, with the perihelion distance slowly increasing to 6.1 AU while the aphelion distance stays in the range of 8.1 to 9.4 AU, i.e. the orbit is again framed by Saturn's orbit on the outside and Jupiter's orbit in the inside. The period of revolution is always between 18.3 and 21.7 years. However, this situation is going to change subsequently to a close encounter with Saturn during the second half of the year 2312 (0.8 ± 0.1 AU). This will bring the comet's perihelion distance (reduced to 5.58 AU in 2400) in precarious vicinity to Jupiter's orbit, which will lead to a very close encounter with Jupiter between mid-2428 and the end of 2431. With a probability of 35% this approach will be closer than 1 AU sometime in 2429, but it could be even as close as 0.15 AU/22.3 Mio km. The currently known data about the comet 39P/Oterma do not permit to extrapolate its fate with sufficient certainty beyond this Jupiter rendezvous because shortly after, the comet's orbital parameters will be severely altered in a wide possible range. Only probabilities can be given. Only 10 years after the encounter with Jupiter, the comet can be found with a probability of 11.5% inside the orbit of Jupiter as a “quasi-Hilda comet“ (which would reactivate it to become more easily observed again from Earth). There is even a (very small) probability that the comet gets caught by Jupiter in a satellite capture, but more likely the comet will remain an inactive centaur-like object. A larger probability of 63% sees it continuing in an orbit between Jupiter and Saturn, but there is also a probability of 25% that the comet will become a Saturn-crosser. The orbital eccentricity may be distributed in a wide range from 0.03 to 0.44, while the inclination may be anywhere between 1.6° and 8.5°. References External links 39P at Kronk's Cometography Orbital simulation from JPL (Java) / Ephemeris Centaurs with cometary designation SOLEX & EXORB Orbits handling & determination software by A. Vitagliano Centaurs (small Solar System bodies) Chiron-type comets Periodic comets 0039 Discoveries by Liisi Oterma 20230713 19430408

3854461

https://en.wikipedia.org/wiki/41P/Tuttle%E2%80%93Giacobini%E2%80%93Kres%C3%A1k

41P/Tuttle–Giacobini–Kresák

41P/Tuttle–Giacobini–Kresák is a periodic comet in the Solar System. The comet nucleus is estimated to be 1.4 kilometers in diameter. Discovered by Horace Parnell Tuttle on May 3, 1858, and re-discovered independently by Michel Giacobini and Ľubor Kresák in 1907 and 1951 respectively, it is a member of the Jupiter family of comets. 2006 apparition As of June 1, 2006, Comet 41P was a 10th magnitude object for telescopes, located on the Cancer-Leo border, with a predicted maximum of about 10 at perihelion on June 11. This comet is of interest as it has been noted to flare dramatically. In 1973 the flare was 10 magnitudes brighter than predicted, reaching easy naked-eye visibility at apparent magnitude 4. However, by June 22, the comet had diminished to about magnitude 11, having produced no flare of note. 2011 apparition The comet was not observed during the 2011 unfavorable apparition since the perihelion passage occurred when the comet was on the far side of the Sun. 2017 apparition 41P was recovered on November 10, 2016, at apparent magnitude 21 by Pan-STARRS. On April 1, 2017, the comet passed from the Earth. The comet was expected to brighten to around magnitude 7 and be visible in binoculars. Proposed exploration In the 1960s European Space Research Organisation investigated sending a probe to the comet. References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 41P/Tuttle-Giacobini-Kresak at the Minor Planet Center's Database 41P at Kronk's Cometography Periodic comets 041P 0041 Comets in 2017 18580503

3854529

https://en.wikipedia.org/wiki/42P/Neujmin

42P/Neujmin

42P/Neujmin, also known as Neujmin 3, is a periodic comet 2 km in diameter. This comet and 53P/Van Biesbroeck are fragments of a parent comet that split in March 1845. The comet did not come within 1 AU of a planet in the 20th century, but will pass 0.04 AU from asteroid 4 Vesta on July 17, 2036. The comet nucleus is estimated to be 2.2 kilometers in diameter. References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 42P at Kronk's Cometography Periodic comets 0042 Comets in 2015 19290802

3854637

https://en.wikipedia.org/wiki/47P/Ashbrook%E2%80%93Jackson

47P/Ashbrook–Jackson

47P/Ashbrook–Jackson is a periodic comet in the Solar System. The comet nucleus is estimated to be 5.6 kilometers in diameter. History Comet 47P/Ashbrook–Jackson was discovered by Joseph Ashbrook and Cyril Jackson in 1948. Name 47p is in the name because it was the 47th periodic comet discovered. Ashbrook–Jackson is the names of its two discoverers. Apparitions October 28, 2025 June 10, 2017 January 31, 2009 January 6, 2001 July 14, 1993 January 24, 1986 August 19, 1978 March 13, 1971 October 2, 1963 April 6, 1956 October 4, 1948 References External links 47P/Ashbrook-Jackson – Seiichi Yoshida @ aerith.net 47P at Kronk's Cometography / Periodic comets Periodic comets 0047 Comets in 2017 19480826

3854709

https://en.wikipedia.org/wiki/48P/Johnson

48P/Johnson

48P/Johnson is a periodic comet in the Solar System. The comet nucleus is estimated to be 5.7 kilometers in diameter by Lamy, Fernandez, and Weaver. David C. Jewitt and Scott S. Sheppard estimate the nucleus to have dimensions of 6.0 x 4.4 km. References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 48P at Kronk's Cometography 48P/Johnson – Seiichi Yoshida @ aerith.net Lightcurve (Artyom Novichonok) Periodic comets 0048 Comets in 2011 Comets in 2018 19490825

3854777

https://en.wikipedia.org/wiki/49P/Arend%E2%80%93Rigaux

49P/Arend–Rigaux

49P/Arend–Rigaux is a periodic comet in the Solar System. The comet nucleus is estimated to be 8.48 kilometers in diameter with a low albedo of 0.028. On 20 December 2058 the comet will pass from Mars. References External links 49P/Arend-Rigaux – Seiichi Yoshida @ aerith.net Elements and Ephemeris for 49P/Arend-Rigaux – Minor Planet Center 49P at Kronk's Cometography Periodic comets 0049 Comets in 2011 Comets in 2018 19510205

3856885

https://en.wikipedia.org/wiki/Lacus%20Bonitatis

Lacus Bonitatis

Lacus Bonitatis (Latin bonitātis, "Lake of Goodness") is a small lunar mare that lies to the northwest of the prominent crater Macrobius. Further to the north of Lacus Bonitatis is the Montes Taurus mountain range. This mare is an irregular region of basaltic lava with uneven borders. The mare lies within a diameter of 122 km and the longest dimension trends from the southwest to the northeast. The centre coordinates of Lacus Bonitatis are . See also Volcanism on the Moon References Bonitatis, Lacus

3857616

https://en.wikipedia.org/wiki/SuitSat

SuitSat

SuitSat (also known as SuitSat-1, Mr. Smith, Ivan Ivanovich, RadioSkaf, Radio Sputnik, and AMSAT-OSCAR 54) was a retired Russian Orlan space suit with a radio transmitter mounted on its helmet, used as a hand-launched satellite. First devised around 2004, SuitSat-1 was deployed in an ephemeral orbit around the Earth from the International Space Station on February 3, 2006. Contact from SuitSat-1 was lost by February 18, and the satellite burned up on reentry in Earth's atmosphere on September 7. A similar hand-launched satellite, Kedr, was released in 2011 and was initially named SuitSat-2, despite not using a space suit. SuitSat-1 The idea for this OSCAR satellite was first formally discussed at an AMSAT symposium in October 2004, although the ARISS-Russia team is credited with coming up with the idea as a commemorative gesture for the 175th anniversary of the Moscow State Technical University. According to Frank Bauer of NASA's Goddard Space Flight Center, a group of Russian researchers led by Sergey Samburov devised the idea of converting disused space suits into satellites. In a move originally planned for December 6, 2005, SuitSat-1 entered its own independent orbit just after 23:05 UTC on February 3, 2006, when it was released from the International Space Station by Valeri Tokarev and Bill McArthur as part of an unrelated spacewalk. Voice messages recorded by the teams involved, and by students from around the globe, were continuously broadcast in a number of languages from the SuitSat, along with telemetry data. The signal began transmission approximately 15 minutes after SuitSat-1 was jettisoned and was relayed by equipment on board the ISS. Anyone receiving the transmission could log an entry on the tracker at suitsat.org, detailing when and where they heard it. The SuitSat-1 mission was not a total success. There were very few reports that actually confirmed the receiving of the transmission. NASA TV later announced that SuitSat ceased functioning after only two orbits due to battery failure, but there were reports suggesting that SuitSat-1 continued transmitting, albeit far more weakly than expected. The official designation for SuitSat is AMSAT-OSCAR 54, though it was nicknamed "Ivan Ivanovich" or "Mr. Smith". The radio transmitter used a frequency of 145.990 MHz. The last confirmed signal report from SuitSat-1 was the report of KC7GZC on February 18, 2006. All later reports indicate that no signal was received when SuitSat-1 was due to pass over. On September 7, 2006, at 16:00 GMT, SuitSat reentered the Earth's atmosphere over the Southern Ocean at 110.4° East longitude and 46.3° South latitude. It was over a point some 1,400 km south-southwest of Cape Leeuwin, Australia. ARISSat-1 (formerly SuitSat-2) ARISSat-1, formerly SuitSat-2 and also known as Kedr, was another ISS hand-launched satellite. It contained experiments built by students and a software-defined radio capable of supporting a U/v linear transponder, FM telemetry, voice recordings and live SSTV imagery. Unlike SuitSat-1, batteries on ARISSat-1 were charged by solar panels, and had a predicted lifetime of up to six months (an interval during which it was expected to deorbit). Kedr was deployed from the ISS by Sergey Volkov on 3 August 2011, and re-entered Earth's atmosphere in January 2012, having spent 154 days in orbit. In popular culture Decommissioned, a 2021 short film, depicts SuitSat as a haunted entity that gains sentience and attacks the ISS. The short won a finalist position at a filmmaking competition using the Unreal Engine. References External links Microchip in Space - NASA Releases SuitSat-1 with PIC18 Microcontroller AMSAT satellite detail suitsat.org Russian site about SuitSat satellite series SuitSat Audio Recordings and Updates - AJ3U.com NASA press release: "SuitSat: Using a simple police scanner or ham radio, you can listen to a disembodied spacesuit circling Earth." NASA Releases SuitSat 1 includes video and technical details "SuitSat-2 Now Called ARISSat-1" Amateur radio satellites 2005 in spaceflight Spacecraft which reentered in 2006 Spacecraft launched in 2005 Satellites deployed from the International Space Station

3858731

https://en.wikipedia.org/wiki/52P/Harrington%E2%80%93Abell

52P/Harrington–Abell

52P/Harrington–Abell is a periodic comet in the Solar System. It was discovered by Robert G. Harrington and George O. Abell in 1955 on plates from the Palomar Sky Survey taken with the 49-inch Samuel Oschin telescope. It has been seen on every apparition since then. With a period of about seven years, it has been seen close to its perihelia in 1954, 1962, 1969, 1976, 1983, 1991, and 2006. Its orbital period changed from 7.2 to 7.6 years when it passed 0.04 AU from Jupiter in April, 1974. It typically gets no brighter than about magnitude 17. In 1998/1999, it was unexpectedly bright. When recovered on July 21, 1998, by Alain Maury, he expected it to be about magnitude 21 or 22. Instead, he found it to be thousands of times brighter at magnitude 12.2. The next night, its brightness was estimated by others at magnitude 10.9 to 11.8. It may have had a second outburst about 80 days before perihelion. It finally faded to dimmer than magnitude 12 by the end of March, 1999. At its return in 2006, it returned to normal brightness. References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 52P/Harrington-Abell – Seiichi Yoshida @ aerith.net Periodic comets 0052 Summer Science Program Comets in 2014 19550322

3858734

https://en.wikipedia.org/wiki/Hoba%20meteorite

Hoba meteorite

The Hoba ( ) meteorite is named after the farm Hoba West, where it lies, not far from Grootfontein, in the Otjozondjupa Region of Namibia. It has been uncovered, but because of its large mass, has never been moved from where it fell. The main mass is estimated at more than 60 tonnes. It is the largest known intact meteorite (as a single piece) and about twice as massive as the largest fragment of either the Cape York meteorite's 31-tonne Ahnighito kept in the American Museum of Natural History or the Campo del Cielo's 31-tonne Gancedo in Argentina. It is also the most massive naturally occurring piece of iron (actually ferronickel) known on Earth's surface. The name "Hoba" comes from a Khoekhoegowab word meaning "gift". Following its donation to the government in 1987, a visitor centre was constructed with a circular stone access and seating area. Impact The Hoba meteorite's impact is thought to have occurred less than 80,000 years ago. It is inferred that the Earth's atmosphere slowed the object in such a way that it impacted the surface at terminal velocity, thereby remaining intact and causing little excavation (expulsion of earth). Assuming a drag coefficient of about 1.3, the meteor appears to have slowed to about from an entry speed to the atmosphere typically in excess of 10 km/s (22,370 mph). The meteorite is unusual in that it is flat on both major surfaces. Discovery The Hoba meteorite left no preserved crater and its discovery was a chance event. In 1920, when the owner of the land, Jacobus Hermanus Brits, encountered the object while ploughing one of his fields with an ox. While working the field, he heard a loud metallic scratching sound and the plough came to an abrupt halt. The obstruction was excavated, identified as a meteorite and described by Mr. Brits, whose report was published in 1920 and can be viewed at the Grootfontein Museum in Namibia. Friedrich Wilhelm Kegel took the first published photograph of the Hoba meteorite. Description and composition Hoba is a tabular body of metal, measuring . In 1920, its mass was estimated at 66 tonnes. Erosion, scientific sampling and vandalism reduced its bulk over the years. The remaining mass is estimated at just over 64 tonnes. The meteorite is composed of about 84% iron and 16% nickel, with traces of cobalt. It is classified as an ataxite iron meteorite belonging to the nickel-rich chemical class IVB. A crust of iron hydroxides is present on the surface due to weathering oxidation. Modern history In an attempt to control relocation attempts, with permission from the farm owner, Mrs O Scheel, on March 15, 1955, the government of South West Africa (now Namibia) declared the Hoba meteorite to be a national monument. Since 1979 the proclamation has been extended to an area of 425 m². From about the 1970s, development of the meteorite site for tourism was hampered by its location in the Otavi triangle of Otavi, Tsumeb and Grootfontein, a key arena of the Namibian war of independence or South African Border War. The war and liberation struggle ended with the 1988 Tripartite Accord. General elections under universal franchise, in 1989, led to formation of the independent Republic of Namibia in 1990. In 1987, the farm owner donated the meteorite and the site where it lies to the state for educational purposes. Later that year, the government opened a tourist centre at the site. As a result of these developments, vandalism of the Hoba meteorite has ceased and it is now visited by thousands of tourists every year. Nevertheless, specimens sourced from earlier theft and vandalism continue to be traded. On the 7th of December 2021, an unusually large 2.8 kg specimen illegally harvested in 1968, was sold for $59,062 in Los Angeles, by international auction house Bonhams. The Bonhams sale notice states " the present specimen was obtained in 1968 by the father of the present owner when he visited the main mass of Hoba together with some friends. Using a hand saw, they cut a large block of the meteorite from the main mass "as a souvenir", an activity which took them between three and four hours", . See also Glossary of meteoritics List of largest meteorites on Earth Notes and references Further reading Universe: The Definitive Visual Dictionary, Robert Dinwiddie, DK Adult Publishing, (2005), pg. 223. Meteorites found in Namibia Otjozondjupa Region Geography of Namibia Geology of Namibia National Monuments of Namibia

3858876

https://en.wikipedia.org/wiki/53P/Van%20Biesbroeck

53P/Van Biesbroeck

53P/Van Biesbroeck is a periodic comet 7 km in diameter. Its current orbital period is 12.53 years. The comet was discovered by George Van Biesbroeck of Yerkes Observatory on 1 September 1954 while searching for the asteroid 1953 GC. The comet had an estimated apparent magnitude of 14.5 and appeared well condensed. The comet was then 1.85 AU from Earth and 2.86 AU from the Sun and had passed from its perigee, which took place on 17 August 1954. The comet was followed until 13 November 1955. This comet and 42P/Neujmin are fragments of a parent comet that split around March 1845. The orbit of 53P/Van Biesbroeck has a Jupiter Minimum orbit intersection distance (MOID) of only . The next perihelion passage is on Christmas Eve 24 December 2028. The comet is expected to brighten to about apparent magnitude 14. The nucleus of the comet has a radius of 3.33–3.37 kilometers based on observations by Keck. References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 53P at Kronk's Cometography Periodic comets 0053 Comets in 2016 19540901

3859157

https://en.wikipedia.org/wiki/56P/Slaughter%E2%80%93Burnham

56P/Slaughter–Burnham

56P/Slaughter–Burnham is a periodic comet in the Solar System with a period of 11.54 years. It was discovered in 1959 by Charles D. Slaughter and Robert Burnham of the Lowell Observatory, Flagstaff, Arizona during a photographic survey. They spotted the comet, with a faint brightness of magnitude 16, on a plate exposed on 10 December 1958. By monitoring its movement over a series of consecutive days, Elizabeth Roemer was able to calculate its orbit, suggesting a perihelion date of 4 August 1958 and an orbital period of 11.18 years. It was subsequently observed in 1970, 1981, 1993, 2005 and 2016. Its next perihelion will be on December 19, 2027. The nucleus of the comet has a radius of 1.55 kilometers based on observations by Keck. References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 56P/Slaughter-Burnham – Seiichi Yoshida @ aerith.net Periodic comets 0056 Comets in 2016 19590127

3865470

https://en.wikipedia.org/wiki/Variation%20%28astronomy%29

Variation (astronomy)

In astronomy, the variation of the Moon is one of the principal perturbations in the motion of the Moon. Discovery The variation was discovered by Tycho Brahe, who noticed that, starting from a lunar eclipse in December 1590, at the times of syzygy (new or full moon), the apparent velocity of motion of the Moon (along its orbit as seen against the background of stars) was faster than expected. On the other hand, at the times of first and last quarter, its velocity was correspondingly slower than expected. (Those expectations were based on the lunar tables widely used up to Tycho's time. They took some account of the two largest irregularities in the Moon's motion, i.e. those now known as the equation of the center and the evection, see also Lunar theory - History.) Variation The main visible effect (in longitude) of the variation of the Moon is that during the course of every month, at the octants of the Moon's phase that follow the syzygies (i.e. halfway between the new or the full moon and the next-following quarter), the Moon is about two thirds of a degree farther ahead than would be expected on the basis of its mean motion (as modified by the equation of the centre and by the evection). But at the octants that precede the syzygies, it is about two thirds of a degree behind. At the syzygies and quarters themselves, the main effect is on the Moon's velocity rather than its position. In 1687 Newton published, in the 'Principia', his first steps in the gravitational analysis of the motion of three mutually-attracting bodies. This included a proof that the Variation is one of the results of the perturbation of the motion of the Moon caused by the action of the Sun, and that one of the effects is to distort the Moon's orbit in a practically elliptical manner (ignoring at this point the eccentricity of the Moon's orbit), with the centre of the ellipse occupied by the Earth, and the major axis perpendicular to a line drawn between the Earth and Sun. The Variation has a period of half a synodic month and causes the Moon's ecliptic longitude to vary by nearly two-thirds of a degree, more exactly by +2370"sin(2D) where D is the mean elongation of the Moon from the Sun. The variational distortion of the Moon's orbit is a different effect from the eccentric elliptical motion of a body in an unperturbed orbit. The Variation effect would still occur if the undisturbed motion of the Moon had an eccentricity of zero (i.e. circular). The eccentric Keplerian ellipse is another and separate approximation for the Moon's orbit, different from the approximation represented by the (central) variational ellipse. The Moon's line of apses, i.e. the long axis of the Moon's orbit when approximated as an eccentric ellipse, rotates once in about nine years, so that it can be oriented at any angle whatever relative to the direction of the Sun at any season. (The angular difference between these two directions used to be referred to, in much older literature, as the "annual argument of the Moon's apogee".) Twice in every period of just over a year, the direction of the Sun coincides with the direction of the long axis of the eccentric elliptical approximation of the Moon's orbit (as projected on to the ecliptic). Elliptical distortion Thus the (central) elliptical distortion of the Moon's orbit caused by the variation should not be confused with an undisturbed eccentric elliptical motion of an orbiting body. The variational effects due to the Sun would still occur even if the hypothetical undisturbed motion of the Moon had an eccentricity of zero (i.e. even if the orbit would be circular in the absence of the Sun). Newton expressed an approximate recognition that the real orbit of the Moon is not exactly an eccentric Keplerian ellipse, nor exactly a central ellipse due to the variation, but "an oval of another kind". Newton did not give an explicit expression for the form of this "oval of another kind"; to an approximation, it combines the two effects of the central-elliptical variational orbit and the Keplerian eccentric ellipse. Their combination also continually changes its shape as the annual argument changes, and also as the evection shows itself in libratory changes in the eccentricity, and in the direction, of the long axis of the eccentric ellipse. The Variation is the second-largest solar perturbation of the Moon's orbit after the Evection, and the third-largest inequality in the motion of the Moon altogether; (the first and largest of the lunar inequalities is the equation of the centre, a result of the eccentricity – which is not an effect of solar perturbation). See also Evection References Bibliography Brown, E.W. An Introductory Treatise on the Lunar Theory. Cambridge University Press, 1896 (republished by Dover, 1960). Celestial mechanics

3866417

https://en.wikipedia.org/wiki/60P/Tsuchinshan

60P/Tsuchinshan

60P/Tsuchinshan, also known as Tsuchinshan 2, is a periodic comet in the Solar System with an orbital period of 6.79 years. Tsuchinshan is the Wade-Giles transliteration corresponding to the pinyin Zĭjīn Shān, which is Mandarin Chinese for "Purple Mountain". It was discovered at the Purple Mountain Observatory, Nanking, China on 11 January 1965 with a magnitude estimated as a very faint 15. The elliptical orbit was computed to give a perihelion date of 9 February 1965 with an orbital period of 6.69 years. Revised calculations predicted the next perihelion would be on 28 November 1971 and Elizabeth Roemer of the University of Arizona successfully relocated the comet with the 154-cm reflector at Catalina. It was also observed in 1978, 1985, 1991-1992, and 1998-1999. The comet peaked at about apparent magnitude 16.3 in 2012. On 29 December 2077 the comet will pass from Mars. See also List of numbered comets References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 60P/Tsuchinshan 2 – Seiichi Yoshida @ aerith.net Elements and Ephemeris for 60P/Tsuchinshan – Minor Planet Center 60P at Kronk's Cometography 60P with UGC 6510 (2019-Jan-10) Periodic comets 0060 19650111

3866485

https://en.wikipedia.org/wiki/65P/Gunn

65P/Gunn

65P/Gunn is a periodic comet in the Solar System which has a current orbital period of 6.79 years. The comet is a short-period comet, orbiting the Sun every 6.79 years inside the main asteroid belt between the orbits of the planets Mars and Jupiter. It was discovered on 11 October 1970 by Professor James E. Gunn of Princeton University using the 122-cm Schmidt telescope at the Palomar Observatory. It had a low brightness of magnitude 16 plus which improves to 12 under favourable conditions. In 1972 Elizabeth Roemer managed to observe 65P/Gunn close to aphelion. On 4 February 1970 the comet passed from Ceres. In 1980 was noticed that a 19th magnitude comet found in plates obtained by Palomar Observatory on 8 August 1954 was a previous apparition of 65/Gunn. The link was confirmed by Brian G. Marsden. See also List of numbered comets References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 65P at Kronk's Cometography 65P/Gunn – Seiichi Yoshida @ aerith.net 65P at Las Cumbres Observatory (26 Jun 2010 11:16, 150 seconds) Periodic comets 0065 Comets in 2017 19701011

3871014

https://en.wikipedia.org/wiki/Rainbow

Rainbow

A rainbow is an optical phenomenon caused by refraction, internal reflection and dispersion of light in water droplets resulting in a continuous spectrum of light appearing in the sky. The rainbow takes the form of a multicoloured circular arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the Sun. Rainbows can be caused by many forms of airborne water. These include not only rain, but also mist, spray, and airborne dew. Rainbows can be full circles. However, the observer normally sees only an arc formed by illuminated droplets above the ground, and centered on a line from the Sun to the observer's eye. In a primary rainbow, the arc shows red on the outer part and violet on the inner side. This rainbow is caused by light being refracted when entering a droplet of water, then reflected inside on the back of the droplet and refracted again when leaving it. In a double rainbow, a second arc is seen outside the primary arc, and has the order of its colours reversed, with red on the inner side of the arc. This is caused by the light being reflected twice on the inside of the droplet before leaving it. Visibility Rainbows can be observed whenever there are water drops in the air and sunlight shining from behind the observer at a low altitude angle. Because of this, rainbows are usually seen in the western sky during the morning and in the eastern sky during the early evening. The most spectacular rainbow displays happen when half the sky is still dark with raining clouds and the observer is at a spot with clear sky in the direction of the Sun. The result is a luminous rainbow that contrasts with the darkened background. During such good visibility conditions, the larger but fainter secondary rainbow is often visible. It appears about 10° outside of the primary rainbow, with inverse order of colours. The rainbow effect is also commonly seen near waterfalls or fountains. In addition, the effect can be artificially created by dispersing water droplets into the air during a sunny day. Rarely, a moonbow, lunar rainbow or nighttime rainbow, can be seen on strongly moonlit nights. As human visual perception for colour is poor in low light, moonbows are often perceived to be white. It is difficult to photograph the complete semicircle of a rainbow in one frame, as this would require an angle of view of 84°. For a 35 mm camera, a wide-angle lens with a focal length of 19 mm or less would be required. Now that software for stitching several images into a panorama is available, images of the entire arc and even secondary arcs can be created fairly easily from a series of overlapping frames. From above the Earth such as in an aeroplane, it is sometimes possible to see a rainbow as a full circle. This phenomenon can be confused with the glory phenomenon, but a glory is usually much smaller, covering only 5–20°. The sky inside a primary rainbow is brighter than the sky outside of the bow. This is because each raindrop is a sphere and it scatters light over an entire circular disc in the sky. The radius of the disc depends on the wavelength of light, with red light being scattered over a larger angle than blue light. Over most of the disc, scattered light at all wavelengths overlaps, resulting in white light which brightens the sky. At the edge, the wavelength dependence of the scattering gives rise to the rainbow. The light of a primary rainbow arc is 96% polarised tangential to the arc. The light of the second arc is 90% polarised. Number of colours in a spectrum or a rainbow For colours seen by the human eye, the most commonly cited and remembered sequence is Isaac Newton's sevenfold red, orange, yellow, green, blue, indigo and violet, remembered by the mnemonic Richard Of York Gave Battle In Vain, or as the name of a fictional person (Roy G. Biv). The initialism is sometimes referred to in reverse order, as VIBGYOR. More modernly, the rainbow is often divided into red, orange, yellow, green, cyan, blue and violet. The apparent discreteness of main colours is an artefact of human perception and the exact number of main colours is a somewhat arbitrary choice. Newton, who admitted his eyes were not very critical in distinguishing colours, originally (1672) divided the spectrum into five main colours: red, yellow, green, blue and violet. Later he included orange and indigo, giving seven main colours by analogy to the number of notes in a musical scale. Newton chose to divide the visible spectrum into seven colours out of a belief derived from the beliefs of the ancient Greek sophists, who thought there was a connection between the colours, the musical notes, the known objects in the Solar System, and the days of the week. Scholars have noted that what Newton regarded at the time as "blue" would today be regarded as cyan, and what Newton called "indigo" would today be considered blue. The colour pattern of a rainbow is different from a spectrum, and the colours are less saturated. There is spectral smearing in a rainbow owing to the fact that for any particular wavelength, there is a distribution of exit angles, rather than a single unvarying angle. In addition, a rainbow is a blurred version of the bow obtained from a point source, because the disk diameter of the sun (0.5°) cannot be neglected compared to the width of a rainbow (2°). Further red of the first supplementary rainbow overlaps the violet of the primary rainbow, so rather than the final colour being a variant of spectral violet, it is actually a purple. The number of colour bands of a rainbow may therefore be different from the number of bands in a spectrum, especially if the droplets are particularly large or small. Therefore, the number of colours of a rainbow is variable. If, however, the word rainbow is used inaccurately to mean spectrum, it is the number of main colours in the spectrum. Moreover, rainbows have bands beyond red and violet in the respective near infrared and ultraviolet regions, however, these bands are not visible to humans. Only near frequencies of these regions to the visible spectrum are included in rainbows, since water and air become increasingly opaque to these frequencies, scattering the light. The UV band is sometimes visible to cameras using black and white film. The question of whether everyone sees seven colours in a rainbow is related to the idea of linguistic relativity. Suggestions have been made that there is universality in the way that a rainbow is perceived. However, more recent research suggests that the number of distinct colours observed and what these are called depend on the language that one uses, with people whose language has fewer colour words seeing fewer discrete colour bands. Explanation When sunlight encounters a raindrop, part of the light is reflected and the rest enters the raindrop. The light is refracted at the surface of the raindrop. When this light hits the back of the raindrop, some of it is reflected off the back. When the internally reflected light reaches the surface again, once more some is internally reflected and some is refracted as it exits the drop. (The light that reflects off the drop, exits from the back, or continues to bounce around inside the drop after the second encounter with the surface, is not relevant to the formation of the primary rainbow.) The overall effect is that part of the incoming light is reflected back over the range of 0° to 42°, with the most intense light at 42°. This angle is independent of the size of the drop, but does depend on its refractive index. Seawater has a higher refractive index than rain water, so the radius of a "rainbow" in sea spray is smaller than that of a true rainbow. This is visible to the naked eye by a misalignment of these bows. The reason the returning light is most intense at about 42° is that this is a turning point – light hitting the outermost ring of the drop gets returned at less than 42°, as does the light hitting the drop nearer to its centre. There is a circular band of light that all gets returned right around 42°. If the Sun were a laser emitting parallel, monochromatic rays, then the luminance (brightness) of the bow would tend toward infinity at this angle (ignoring interference effects). (See Caustic (optics).) But since the Sun's luminance is finite and its rays are not all parallel (it covers about half a degree of the sky) the luminance does not go to infinity. Furthermore, the amount by which light is refracted depends upon its wavelength, and hence its colour. This effect is called dispersion. Blue light (shorter wavelength) is refracted at a greater angle than red light, but due to the reflection of light rays from the back of the droplet, the blue light emerges from the droplet at a smaller angle to the original incident white light ray than the red light. Due to this angle, blue is seen on the inside of the arc of the primary rainbow, and red on the outside. The result of this is not only to give different colours to different parts of the rainbow, but also to diminish the brightness. (A "rainbow" formed by droplets of a liquid with no dispersion would be white, but brighter than a normal rainbow.) The light at the back of the raindrop does not undergo total internal reflection, and some light does emerge from the back. However, light coming out the back of the raindrop does not create a rainbow between the observer and the Sun because spectra emitted from the back of the raindrop do not have a maximum of intensity, as the other visible rainbows do, and thus the colours blend together rather than forming a rainbow. A rainbow does not exist at one particular location. Many rainbows exist; however, only one can be seen depending on the particular observer's viewpoint as droplets of light illuminated by the sun. All raindrops refract and reflect the sunlight in the same way, but only the light from some raindrops reaches the observer's eye. This light is what constitutes the rainbow for that observer. The whole system composed by the Sun's rays, the observer's head, and the (spherical) water drops has an axial symmetry around the axis through the observer's head and parallel to the Sun's rays. The rainbow is curved because the set of all the raindrops that have the right angle between the observer, the drop, and the Sun, lie on a cone pointing at the sun with the observer at the tip. The base of the cone forms a circle at an angle of 40–42° to the line between the observer's head and their shadow but 50% or more of the circle is below the horizon, unless the observer is sufficiently far above the earth's surface to see it all, for example in an aeroplane (see below). Alternatively, an observer with the right vantage point may see the full circle in a fountain or waterfall spray. Mathematical derivation It is possible to determine the perceived angle which the rainbow subtends as follows. Given a spherical raindrop, and defining the perceived angle of the rainbow as , and the angle of the internal reflection as , then the angle of incidence of the Sun's rays with respect to the drop's surface normal is . Since the angle of refraction is , Snell's law gives us , where is the refractive index of water. Solving for , we get . The rainbow will occur where the angle is maximum with respect to the angle . Therefore, from calculus, we can set , and solve for , which yields Substituting back into the earlier equation for yields ≈ 42° as the radius angle of the rainbow. For red light (wavelength 750nm, based on the dispersion relation of water), the radius angle is 42.5°; for blue light (wavelength 350nm, ), the radius angle is 40.6°. Variations Double rainbows A secondary rainbow, at a greater angle than the primary rainbow, is often visible. The term double rainbow is used when both the primary and secondary rainbows are visible. In theory, all rainbows are double rainbows, but since the secondary bow is always fainter than the primary, it may be too weak to spot in practice. Secondary rainbows are caused by a double reflection of sunlight inside the water droplets. Technically the secondary bow is centred on the sun itself, but since its angular size is more than 90° (about 127° for violet to 130° for red), it is seen on the same side of the sky as the primary rainbow, about 10° outside it at an apparent angle of 50–53°. As a result of the "inside" of the secondary bow being "up" to the observer, the colours appear reversed compared to those of the primary bow. The secondary rainbow is fainter than the primary because more light escapes from two reflections compared to one and because the rainbow itself is spread over a greater area of the sky. Each rainbow reflects white light inside its coloured bands, but that is "down" for the primary and "up" for the secondary. The dark area of unlit sky lying between the primary and secondary bows is called Alexander's band, after Alexander of Aphrodisias, who first described it. Twinned rainbow Unlike a double rainbow that consists of two separate and concentric rainbow arcs, the very rare twinned rainbow appears as two rainbow arcs that split from a single base. The colours in the second bow, rather than reversing as in a secondary rainbow, appear in the same order as the primary rainbow. A "normal" secondary rainbow may be present as well. Twinned rainbows can look similar to, but should not be confused with supernumerary bands. The two phenomena may be told apart by their difference in colour profile: supernumerary bands consist of subdued pastel hues (mainly pink, purple and green), while the twinned rainbow shows the same spectrum as a regular rainbow. The cause of a twinned rainbow is believed to be the combination of different sizes of water drops falling from the sky. Due to air resistance, raindrops flatten as they fall, and flattening is more prominent in larger water drops. When two rain showers with different-sized raindrops combine, they each produce slightly different rainbows which may combine and form a twinned rainbow. A numerical ray tracing study showed that a twinned rainbow on a photo could be explained by a mixture of 0.40 and 0.45 mm droplets. That small difference in droplet size resulted in a small difference in flattening of the droplet shape, and a large difference in flattening of the rainbow top. Meanwhile, the even rarer case of a rainbow split into three branches was observed and photographed in nature. Full-circle rainbow In theory, every rainbow is a circle, but from the ground, usually only its upper half can be seen. Since the rainbow's centre is diametrically opposed to the Sun's position in the sky, more of the circle comes into view as the sun approaches the horizon, meaning that the largest section of the circle normally seen is about 50% during sunset or sunrise. Viewing the rainbow's lower half requires the presence of water droplets below the observer's horizon, as well as sunlight that is able to reach them. These requirements are not usually met when the viewer is at ground level, either because droplets are absent in the required position, or because the sunlight is obstructed by the landscape behind the observer. From a high viewpoint such as a high building or an aircraft, however, the requirements can be met and the full-circle rainbow can be seen. Like a partial rainbow, the circular rainbow can have a secondary bow or supernumerary bows as well. It is possible to produce the full circle when standing on the ground, for example by spraying a water mist from a garden hose while facing away from the sun. A circular rainbow should not be confused with the glory, which is much smaller in diameter and is created by different optical processes. In the right circumstances, a glory and a (circular) rainbow or fog bow can occur together. Another atmospheric phenomenon that may be mistaken for a "circular rainbow" is the 22° halo, which is caused by ice crystals rather than liquid water droplets, and is located around the Sun (or Moon), not opposite it. Supernumerary rainbows In certain circumstances, one or several narrow, faintly coloured bands can be seen bordering the violet edge of a rainbow; i.e., inside the primary bow or, much more rarely, outside the secondary. These extra bands are called supernumerary rainbows or supernumerary bands; together with the rainbow itself the phenomenon is also known as a stacker rainbow. The supernumerary bows are slightly detached from the main bow, become successively fainter along with their distance from it, and have pastel colours (consisting mainly of pink, purple and green hues) rather than the usual spectrum pattern. The effect becomes apparent when water droplets are involved that have a diameter of about 1 mm or less; the smaller the droplets are, the broader the supernumerary bands become, and the less saturated their colours. Due to their origin in small droplets, supernumerary bands tend to be particularly prominent in fogbows. Supernumerary rainbows cannot be explained using classical geometric optics. The alternating faint bands are caused by interference between rays of light following slightly different paths with slightly varying lengths within the raindrops. Some rays are in phase, reinforcing each other through constructive interference, creating a bright band; others are out of phase by up to half a wavelength, cancelling each other out through destructive interference, and creating a gap. Given the different angles of refraction for rays of different colours, the patterns of interference are slightly different for rays of different colours, so each bright band is differentiated in colour, creating a miniature rainbow. Supernumerary rainbows are clearest when raindrops are small and of uniform size. The very existence of supernumerary rainbows was historically a first indication of the wave nature of light, and the first explanation was provided by Thomas Young in 1804. Reflected rainbow, reflection rainbow When a rainbow appears above a body of water, two complementary mirror bows may be seen below and above the horizon, originating from different light paths. Their names are slightly different. A reflected rainbow may appear in the water surface below the horizon. The sunlight is first deflected by the raindrops, and then reflected off the body of water, before reaching the observer. The reflected rainbow is frequently visible, at least partially, even in small puddles. A reflection rainbow may be produced where sunlight reflects off a body of water before reaching the raindrops, if the water body is large, quiet over its entire surface, and close to the rain curtain. The reflection rainbow appears above the horizon. It intersects the normal rainbow at the horizon, and its arc reaches higher in the sky, with its centre as high above the horizon as the normal rainbow's centre is below it. Reflection bows are usually brightest when the sun is low because at that time its light is most strongly reflected from water surfaces. As the sun gets lower the normal and reflection bows are drawn closer together. Due to the combination of requirements, a reflection rainbow is rarely visible. Up to eight separate bows may be distinguished if the reflected and reflection rainbows happen to occur simultaneously: The normal (non-reflection) primary and secondary bows above the horizon (1, 2) with their reflected counterparts below it (3, 4), and the reflection primary and secondary bows above the horizon (5, 6) with their reflected counterparts below it (7, 8). Monochrome rainbow Occasionally a shower may happen at sunrise or sunset, where the shorter wavelengths like blue and green have been scattered and essentially removed from the spectrum. Further scattering may occur due to the rain, and the result can be the rare and dramatic monochrome or red rainbow. Higher-order rainbows In addition to the common primary and secondary rainbows, it is also possible for rainbows of higher orders to form. The order of a rainbow is determined by the number of light reflections inside the water droplets that create it: One reflection results in the first-order or primary rainbow; two reflections create the second-order or secondary rainbow. More internal reflections cause bows of higher orders—theoretically unto infinity. As more and more light is lost with each internal reflection, however, each subsequent bow becomes progressively dimmer and therefore increasingly difficult to spot. An additional challenge in observing the third-order (or tertiary) and fourth-order (quaternary) rainbows is their location in the direction of the sun (about 40° and 45° from the sun, respectively), causing them to become drowned in its glare. For these reasons, naturally occurring rainbows of an order higher than 2 are rarely visible to the naked eye. Nevertheless, sightings of the third-order bow in nature have been reported, and in 2011 it was photographed definitively for the first time. Shortly after, the fourth-order rainbow was photographed as well, and in 2014 the first ever pictures of the fifth-order (or quinary) rainbow were published. The quinary rainbow lies partially in the gap between the primary and secondary rainbows and is far fainter than even the secondary. In a laboratory setting, it is possible to create bows of much higher orders. Felix Billet (1808–1882) depicted angular positions up to the 19th-order rainbow, a pattern he called a "rose of rainbows". In the laboratory, it is possible to observe higher-order rainbows by using extremely bright and well collimated light produced by lasers. Up to the 200th-order rainbow was reported by Ng et al. in 1998 using a similar method but an argon ion laser beam. Tertiary and quaternary rainbows should not be confused with "triple" and "quadruple" rainbows—terms sometimes erroneously used to refer to the (much more common) supernumerary bows and reflection rainbows. Rainbows under moonlight Like most atmospheric optical phenomena, rainbows can be caused by light from the Sun, but also from the Moon. In case of the latter, the rainbow is referred to as a lunar rainbow or moonbow. They are much dimmer and rarer than solar rainbows, requiring the Moon to be near-full in order for them to be seen. For the same reason, moonbows are often perceived as white and may be thought of as monochrome. The full spectrum is present, however, but the human eye is not normally sensitive enough to see the colours. Long exposure photographs will sometimes show the colour in this type of rainbow. Fogbow Fogbows form in the same way as rainbows, but they are formed by much smaller cloud and fog droplets that diffract light extensively. They are almost white with faint reds on the outside and blues inside; often one or more broad supernumerary bands can be discerned inside the inner edge. The colours are dim because the bow in each colour is very broad and the colours overlap. Fogbows are commonly seen over water when air in contact with the cooler water is chilled, but they can be found anywhere if the fog is thin enough for the sun to shine through and the sun is fairly bright. They are very large—almost as big as a rainbow and much broader. They sometimes appear with a glory at the bow's centre. Fog bows should not be confused with ice halos, which are very common around the world and visible much more often than rainbows (of any order), yet are unrelated to rainbows. Sleetbow A sleetbow forms in the same way as a typical rainbow, with the exception that it occurs when light passes through falling sleet (ice pellets) instead of liquid water. As light passes through the sleet, the light is refracted causing the rare phenomena. These have been documented across United States with the earliest publicly documented and photographed sleetbow being seen in Richmond, Virginia on December 21, 2012. Just like regular rainbows, these can also come in various forms, with a monochrome sleetbow being documented on January 7, 2016 in Valparaiso, Indiana. Circumhorizontal and circumzenithal arcs The circumzenithal and circumhorizontal arcs are two related optical phenomena similar in appearance to a rainbow, but unlike the latter, their origin lies in light refraction through hexagonal ice crystals rather than liquid water droplets. This means that they are not rainbows, but members of the large family of halos. Both arcs are brightly coloured ring segments centred on the zenith, but in different positions in the sky: The circumzenithal arc is notably curved and located high above the Sun (or Moon) with its convex side pointing downwards (creating the impression of an "upside down rainbow"); the circumhorizontal arc runs much closer to the horizon, is more straight and located at a significant distance below the Sun (or Moon). Both arcs have their red side pointing towards the Sun and their violet part away from it, meaning the circumzenithal arc is red on the bottom, while the circumhorizontal arc is red on top. The circumhorizontal arc is sometimes referred to by the misnomer "fire rainbow". In order to view it, the Sun or Moon must be at least 58° above the horizon, making it a rare occurrence at higher latitudes. The circumzenithal arc, visible only at a solar or lunar elevation of less than 32°, is much more common, but often missed since it occurs almost directly overhead. Extraterrestrial rainbows It has been suggested that rainbows might exist on Saturn's moon Titan, as it has a wet surface and humid clouds. The radius of a Titan rainbow would be about 49° instead of 42°, because the fluid in that cold environment is methane instead of water. Although visible rainbows may be rare due to Titan's hazy skies, infrared rainbows may be more common, but an observer would need infrared night vision goggles to see them. Rainbows with different materials Droplets (or spheres) composed of materials with different refractive indices than plain water produce rainbows with different radius angles. Since salt water has a higher refractive index, a sea spray bow does not perfectly align with the ordinary rainbow, if seen at the same spot. Tiny plastic or glass marbles may be used in road marking as a reflectors to enhance its visibility by drivers at night. Due to a much higher refractive index, rainbows observed on such marbles have a noticeably smaller radius. One can easily reproduce such phenomena by sprinkling liquids of different refractive indices in the air, as illustrated in the photo. The displacement of the rainbow due to different refractive indices can be pushed to a peculiar limit. For a material with a refractive index larger than 2, there is no angle fulfilling the requirements for the first order rainbow. For example, the index of refraction of diamond is about 2.4, so diamond spheres would produce rainbows starting from the second order, omitting the first order. In general, as the refractive index exceeds a number , where is a natural number, the critical incidence angle for times internally reflected rays escapes the domain . This results in a rainbow of the -th order shrinking to the antisolar point and vanishing. Scientific history The classical Greek scholar Aristotle (384–322 BC) was first to devote serious attention to the rainbow. According to Raymond L. Lee and Alistair B. Fraser, "Despite its many flaws and its appeal to Pythagorean numerology, Aristotle's qualitative explanation showed an inventiveness and relative consistency that was unmatched for centuries. After Aristotle's death, much rainbow theory consisted of reaction to his work, although not all of this was uncritical." In Book I of Naturales Quaestiones (), the Roman philosopher Seneca the Younger discusses various theories of the formation of rainbows extensively, including those of Aristotle. He notices that rainbows appear always opposite to the Sun, that they appear in water sprayed by a rower, in the water spat by a fuller on clothes stretched on pegs or by water sprayed through a small hole in a burst pipe. He even speaks of rainbows produced by small rods (virgulae) of glass, anticipating Newton's experiences with prisms. He takes into account two theories: one, that the rainbow is produced by the Sun reflecting in each water drop, the other, that it is produced by the Sun reflected in a cloud shaped like a concave mirror; he favours the latter. He also discusses other phenomena related to rainbows: the mysterious "virgae" (rods), halos and parhelia. According to Hüseyin Gazi Topdemir, the Arab physicist and polymath Ibn al-Haytham (Alhazen; 965–1039), attempted to provide a scientific explanation for the rainbow phenomenon. In his Maqala fi al-Hala wa Qaws Quzah (On the Rainbow and Halo), al-Haytham "explained the formation of rainbow as an image, which forms at a concave mirror. If the rays of light coming from a farther light source reflect to any point on axis of the concave mirror, they form concentric circles in that point. When it is supposed that the sun as a farther light source, the eye of viewer as a point on the axis of mirror and a cloud as a reflecting surface, then it can be observed the concentric circles are forming on the axis." He was not able to verify this because his theory that "light from the sun is reflected by a cloud before reaching the eye" did not allow for a possible experimental verification. This explanation was repeated by Averroes, and, though incorrect, provided the groundwork for the correct explanations later given by Kamāl al-Dīn al-Fārisī in 1309 and, independently, by Theodoric of Freiberg (c. 1250–c. 1311)—both having studied al-Haytham's Book of Optics. Ibn al-Haytham's contemporary, the Persian philosopher and polymath Ibn Sīnā (Avicenna; 980–1037), provided an alternative explanation, writing "that the bow is not formed in the dark cloud but rather in the very thin mist lying between the cloud and the sun or observer. The cloud, he thought, serves simply as the background of this thin substance, much as a quicksilver lining is placed upon the rear surface of the glass in a mirror. Ibn Sīnā would change the place not only of the bow, but also of the colour formation, holding the iridescence to be merely a subjective sensation in the eye." This explanation, however, was also incorrect. Ibn Sīnā's account accepts many of Aristotle's arguments on the rainbow. In Song dynasty China (960–1279), a polymath scholar-official named Shen Kuo (1031–1095) hypothesised—as a certain Sun Sikong (1015–1076) did before him—that rainbows were formed by a phenomenon of sunlight encountering droplets of rain in the air. Paul Dong writes that Shen's explanation of the rainbow as a phenomenon of atmospheric refraction "is basically in accord with modern scientific principles." According to Nader El-Bizri, the Persian astronomer, Qutb al-Din al-Shirazi (1236–1311), gave a fairly accurate explanation for the rainbow phenomenon. This was elaborated on by his student, Kamāl al-Dīn al-Fārisī (1267–1319), who gave a more mathematically satisfactory explanation of the rainbow. He "proposed a model where the ray of light from the sun was refracted twice by a water droplet, one or more reflections occurring between the two refractions." An experiment with a water-filled glass sphere was conducted and al-Farisi showed the additional refractions due to the glass could be ignored in his model. As he noted in his Kitab Tanqih al-Manazir (The Revision of the Optics), al-Farisi used a large clear vessel of glass in the shape of a sphere, which was filled with water, in order to have an experimental large-scale model of a rain drop. He then placed this model within a camera obscura that has a controlled aperture for the introduction of light. He projected light unto the sphere and ultimately deduced through several trials and detailed observations of reflections and refractions of light that the colours of the rainbow are phenomena of the decomposition of light. In Europe, Ibn al-Haytham's Book of Optics was translated into Latin and studied by Robert Grosseteste. His work on light was continued by Roger Bacon, who wrote in his of 1268 about experiments with light shining through crystals and water droplets showing the colours of the rainbow. In addition, Bacon was the first to calculate the angular size of the rainbow. He stated that the rainbow summit can not appear higher than 42° above the horizon. Theodoric of Freiberg is known to have given an accurate theoretical explanation of both the primary and secondary rainbows in 1307. He explained the primary rainbow, noting that "when sunlight falls on individual drops of moisture, the rays undergo two refractions (upon ingress and egress) and one reflection (at the back of the drop) before transmission into the eye of the observer." He explained the secondary rainbow through a similar analysis involving two refractions and two reflections. Descartes' 1637 treatise, Discourse on Method, further advanced this explanation. Knowing that the size of raindrops did not appear to affect the observed rainbow, he experimented with passing rays of light through a large glass sphere filled with water. By measuring the angles that the rays emerged, he concluded that the primary bow was caused by a single internal reflection inside the raindrop and that a secondary bow could be caused by two internal reflections. He supported this conclusion with a derivation of the law of refraction (subsequently to, but independently of, Snell) and correctly calculated the angles for both bows. His explanation of the colours, however, was based on a mechanical version of the traditional theory that colours were produced by a modification of white light. Isaac Newton demonstrated that white light was composed of the light of all the colours of the rainbow, which a glass prism could separate into the full spectrum of colours, rejecting the theory that the colours were produced by a modification of white light. He also showed that red light is refracted less than blue light, which led to the first scientific explanation of the major features of the rainbow. Newton's corpuscular theory of light was unable to explain supernumerary rainbows, and a satisfactory explanation was not found until Thomas Young realised that light behaves as a wave under certain conditions, and can interfere with itself. Young's work was refined in the 1820s by George Biddell Airy, who explained the dependence of the strength of the colours of the rainbow on the size of the water droplets. Modern physical descriptions of the rainbow are based on Mie scattering, work published by Gustav Mie in 1908. Advances in computational methods and optical theory continue to lead to a fuller understanding of rainbows. For example, Nussenzveig provides a modern overview. Experiments Experiments on the rainbow phenomenon using artificial raindrops, i.e. water-filled spherical flasks, go back at least to Theodoric of Freiberg in the 14th century. Later, also Descartes studied the phenomenon using a Florence flask. A flask experiment known as Florence's rainbow is still often used today as an imposing and intuitively accessible demonstration experiment of the rainbow phenomenon. It consists in illuminating (with parallel white light) a water-filled spherical flask through a hole in a screen. A rainbow will then appear thrown back / projected on the screen, provided the screen is large enough. Due to the finite wall thickness and the macroscopic character of the artificial raindrop, several subtle differences exist as compared to the natural phenomenon, including slightly changed rainbow angles and a splitting of the rainbow orders. A very similar experiment consists in using a cylindrical glass vessel filled with water or a solid transparent cylinder and illuminated either parallel to the circular base (i.e. light rays remaining at a fixed height while they transit the cylinder) or under an angle to the base. Under these latter conditions the rainbow angles change relative to the natural phenomenon since the effective index of refraction of water changes (Bravais' index of refraction for inclined rays applies). Other experiments use small liquid drops, see text above. Culture and mythology Rainbows occur frequently in mythology, and have been used in the arts. The first literary occurrence of a rainbow is in the Book of Genesis chapter 9, as part of the flood story of Noah, where it is a sign of God's covenant to never destroy all life on Earth with a global flood again. In Norse mythology, the rainbow bridge Bifröst connects the world of men (Midgard) and the realm of the gods (Asgard). Cuchavira was the god of the rainbow for the Muisca in present-day Colombia and when the regular rains on the Bogotá savanna were over, the people thanked him offering gold, snails and small emeralds. Some forms of Tibetan Buddhism or Dzogchen reference a rainbow body. The Irish leprechaun's secret hiding place for his pot of gold is usually said to be at the end of the rainbow. This place is appropriately impossible to reach, because the rainbow is an optical effect which cannot be approached. In Greek mythology, the goddess Iris is the personification of the rainbow, a messenger goddess who, like the rainbow, connects the mortal world with the gods through messages. Rainbows appear in heraldry - in heraldry the rainbow proper consists of 4 bands of colour (Or, Gules, Vert, Argent) with the ends resting on clouds. Generalised examples in coat of arms include those of the towns of Regen and Pfreimd, both in Bavaria, Germany; of Bouffémont, France; and of the 69th Infantry Regiment (New York) of the United States Army National Guard. Rainbow flags have been used for centuries. It was a symbol of the Cooperative movement in the German Peasants' War in the 16th century, of peace in Italy, and of LGBT pride and LGBT social movements; the rainbow flag as a symbol of LGBT pride and the June pride month since it was designed by Gilbert Baker in 1978. In 1994, Archbishop Desmond Tutu and President Nelson Mandela described newly democratic post-apartheid South Africa as the rainbow nation. The rainbow has also been used in technology product logos, including the Apple computer logo. Many political alliances spanning multiple political parties have called themselves a "Rainbow Coalition". Pointing at rainbows has been considered a taboo in many cultures. In Saudi Arabia (and some other countries), authorities seize rainbow-coloured children's clothing and toys (such as hats, hair clips, and pencil cases, not just flags), which they claim encourage homosexuality, and selling such is illegal. See also Atmospheric optics Circumzenithal arc Circumhorizontal arc Glory (optical phenomenon) Iridescent colours in soap bubbles Sun dog Fog bow Moonbow Notes References Further reading (Large format handbook for the Summer 1976 exhibition The Rainbow Art Show which took place primarily at the De Young Museum but also at other museums. The book is divided into seven sections, each coloured a different colour of the rainbow.) External links The Mathematics of Rainbows, article from the American mathematical society Interactive simulation of light refraction in a drop (java applet) Rainbow seen through infrared filter and through ultraviolet filter Atmospheric Optics website by Les Cowley – Description of multiple types of bows, including: "bows that cross, red bows, twinned bows, coloured fringes, dark bands, spokes", etc. Creating Circular and Double Rainbows! – video explanation of basics, shown artificial rainbow at night, second rainbow and circular one. Atmospheric optical phenomena Lucky symbols Heraldic charges LGBT symbols Atmospheric sciences

3876442

https://en.wikipedia.org/wiki/Akari%20%28satellite%29

Akari (satellite)

AKARI (ASTRO-F) was an infrared astronomy satellite developed by Japan Aerospace Exploration Agency, in cooperation with institutes of Europe and Korea. It was launched on 21 February 2006, at 21:28 UTC (06:28, 22 February JST) by M-V rocket into Earth Sun-synchronous orbit. After its launch it was named AKARI (明かり), which means light in Japanese. Earlier on, the project was known as IRIS (InfraRed Imaging Surveyor). Its primary mission was to survey the entire sky in near-, mid- and far-infrared, through its aperture telescope. Technical design Its designed lifespan, of far- and mid-infrared sensors, was 550 days, limited by its liquid helium coolant. Its telescope mirror was made of silicon carbide to save weight. The budget for the satellite was ¥13,4 billion (~). History By mid-August 2006, AKARI finished around 50 per cent of the all sky survey. By early November 2006, first (phase-1) all-sky survey finished. Second (phase-2) all-sky survey started on 10 November 2006. Due to the malfunction of sun-sensor after the launch, ejection of telescope aperture lid was delayed, resulting in the coolant lifespan estimate being shortened to about 500 days from launch. However, after JAXA estimated the remaining helium during early March 2007, observation time was extended at least until 9 September. On 11 July 2007, JAXA informed that 90 per cent of the sky was scanned twice. Also around 3,500 selected targets have been observed so far. On 26 August 2007, liquid-Helium coolant depleted, which means the completion of far- and mid-infrared observation. More than 96 per cent of the sky was scanned and more than 5,000 pointed observations were done. British and Japanese project team members were awarded a Daiwa Adrian Prize in 2004, by the Daiwa Anglo-Japanese Foundation in recognition of their collaboration. During December 2007, JAXA performed orbit correction manoeuvres to bring AKARI back into its ideal orbit. This was necessary because the boiled off helium led to an increase in altitude. If this had continued, the energy supply would have been cut off. 2008-2010 A limited observation 'warm' programme continued with just NIR. End of mission In May 2011, AKARI suffered a major electrical failure and the batteries could not take full charge from the solar panels. As a result, its science instruments were rendered inoperable when the satellite was in the Earth's shadow. The operation of satellite was terminated officially on 24 November 2011. The satellite reentered the atmosphere on 11 April 2023 at 04:44 UTC. Results Star formation over three generations in the nebula IC4954/4955 in the constellation Vulpecula. The first infrared detection of a supernova remnant in the Small Magellanic Cloud Detection of mass-loss from relatively young red-giant stars in the globular cluster NGC 104 Detection of the molecular gas surrounding the active galactic nucleus in the ultra luminous infrared galaxy The constellation Orion and the winter Milky Way at 140 micrometre Star forming region in the constellation Cygnus Active star formation viewed from the outside: The peculiar spiral galaxy M101 Dust processing in the supernova remnants in the Large Magellanic Cloud The AKARI All-Sky Survey Point Source Catalogues was released on 30 March 2010. Astronomy and Astrophysics, Vol. 514 (May 2010) was a feature issue of AKARI's results. See also Infrared astronomy List of largest infrared telescopes List of space telescopes SPICA, proposed (eventually not built) successor space telescope to AKARI References External links JAXA/ISAS AKARI mission information Spacecraft launched in 2006 Spacecraft which reentered in 2023 Infrared telescopes Satellites of Japan Space telescopes

3882879

https://en.wikipedia.org/wiki/Erosion%20control

Erosion control

Erosion control is the practice of preventing or controlling wind or water erosion in agriculture, land development, coastal areas, river banks and construction. Effective erosion controls handle surface runoff and are important techniques in preventing water pollution, soil loss, wildlife habitat loss and human property loss. Usage Erosion controls are used in natural areas, agricultural settings or urban environments. In urban areas erosion controls are often part of stormwater runoff management programs required by local governments. The controls often involve the creation of a physical barrier, such as vegetation or rock, to absorb some of the energy of the wind or water that is causing the erosion. They also involve building and maintaining storm drains. On construction sites they are often implemented in conjunction with sediment controls such as sediment basins and silt fences. Bank erosion is a natural process: without it, rivers would not meander and change course. However, land management patterns that change the hydrograph and/or vegetation cover can act to increase or decrease channel migration rates. In many places, whether or not the banks are unstable due to human activities, people try to keep a river in a single place. This can be done for environmental reclamation or to prevent a river from changing course into land that is being used by people. One way that this is done is by placing riprap or gabions along the bank. Examples Examples of erosion control methods include the following: cellular confinement systems crop rotation conservation tillage contour plowing contour trenching cover crops fiber rolls (also called straw wattles) gabions hydroseeding level spreaders mulching perennial crops plasticulture polyacrylamide (as a coagulant) reforestation riparian buffer riprap strip farming sand fence vegetated waterway (bioswale) terracing windbreaks Mathematical modeling Since the 1920s and 1930s scientists have been creating mathematical models for understanding the mechanisms of soil erosion and resulting sediment surface runoff, including an early paper by Albert Einstein applying Baer's law. These models have addressed both gully and sheet erosion. Earliest models were a simple set of linked equations which could be employed by manual calculation. By the 1970s the models had expanded to complex computer models addressing nonpoint source pollution with thousands of lines of computer code. The more complex models were able to address nuances in micrometeorology, soil particle size distributions and micro-terrain variation. See also Bridge scour Burned area emergency response Certified Professional in Erosion and Sediment Control Coastal management Dust Bowl Natural Resources Conservation Service (United States) Tillage erosion Universal Soil Loss Equation Vetiver System Notes References Albert Einstein. 1926. Die Ursache der Mäanderbildung der Flußläufe und des sogenannten Baerschen Gesetzes, Die Naturwissenschaften, 11, S. 223–224 C. Michael Hogan, Leda Patmore, Gary Latshaw, Harry Seidman et al. 1973. Computer modeling of pesticide transport in the soil for five instrumented watersheds, U.S. Environmental Protection Agency Southeast Water laboratory, Athens, Ga. by ESL Inc., Sunnyvale, California Robert E. Horton. 1933. The Horton Papers U.S. Natural Resources Conservation Service (NRCS). Washington, DC. "National Conservation Practice Standards." National Handbook of Conservation Practices. Accessed 2009-03-28. External links "Saving Runaway Farm Land", November 1930, Popular Mechanics One of the first articles on the problem of soil erosion control Erosion Control Technology Council - a trade organization that mission is to educate and standardize the erosion control industry International Erosion Control Association - Professional Association, Publications, Training WatchYourDirt.com - Erosion Control Educational Video Resource Soil Bioengineering and Biotechnical Slope Stabilization - Erosion Control subsection of a website on Riparian Habitat Restoration Construction Soil erosion Earthworks (engineering) Riparian zone Sustainable design Water pollution

3887850

https://en.wikipedia.org/wiki/Sungazing

Sungazing

Sungazing is the unsafe practice of looking directly at the Sun. It is sometimes done as part of a spiritual or religious practice, most often near dawn or dusk. The human eye is very sensitive, and exposure to direct sunlight can lead to solar retinopathy, pterygium, cataracts, and often blindness. Studies have shown that even when viewing a solar eclipse the eye can still be exposed to harmful levels of ultraviolet radiation. Movements Referred to as sunning by William Horatio Bates as one of a series of exercises included in his Bates method, it became a popular form of alternative therapy in the early 20th century. His methods were widely debated at the time but ultimately discredited for lack of scientific rigor. The British Medical Journal reported in 1967 that "Bates (1920) advocated prolonged sun-gazing as the treatment of myopia, with disastrous results". See also Inedia (breatharianism) Joseph Plateau Scientific skepticism References External links San Diego State University Dept. of Astronomy information on solar observation safety Natural environment based therapies Alternative medicine Sun Eye injury Eye diseases Naturopathy

3892002

https://en.wikipedia.org/wiki/Tish%20%28Hasidic%20celebration%29

Tish (Hasidic celebration)

A Tish, also tische (, ) is a Shabbat or holiday gathering for Hasidic Jews around their Rabbi or "Rebbe". In Chabad, a tische is called (). It may consist of speeches on Torah subjects, singing of melodies known as (singular ) and ("hymns"), with refreshments being served. Hasidim see it as a moment of great holiness. Within Hasidic Judaism, a refers to any joyous public celebration or gathering or meal by Hasidim at a "table" of their Rebbe. Such a gathering is staged around the blessing of Melchizedek-themed "setting of the table" and so is often referred to in Hebrew as (). Bread and wine are essential elements. Overview During a tische, the Rebbe sits at the head of the table and the Hasidim gather around the table. In large Hasidic movements, only the Rebbe and his immediate family, plus a few close disciples, partake of the actual meal, but small pieces of bread, fish, meat, poultry, farfel, beans, kugel, or fruit, as well as small cups of wine or other beverages, are distributed to all present as shirayim (, lit., remnants). In such large courts, there are often bleachers, known as parentches () in Yiddish, for observers of the tische to stand on. In smaller courts there is usually more food available for observers to partake. Often, in both large and small tischen, the Rebbe will personally distribute shirayim food to individuals. Hasidim believe that the Rebbe will have a personal blessing for each person who partakes of the food he gives them. In some Hasidic movements, the Rebbe only eats his Shabbat meals at the tische, often waiting many hours until the Hasidim have finished their meals to begin his meal with the recitation of the Kiddush prayer. In other courts, the Rebbe begins his meal at home with his family, and then comes to join the Hasidim in the synagogue towards the end the meal. In yet other courts, the entire tische is conducted after the meal has been finished at home. In such a case only dessert, usually consisting of kugel and fruit, is served, as well as soft drinks, usually seltzer-water. Such tisches are known as a Peiros Tische () ("Fruit Tische"). The nature of the tische differs from group to group but during the tische, the Hasidim intently and silently watch the rebbe eating the meal and are extremely eager to receive shirayim ("leftovers"), cooked alongside the Rebbe's courses, believing it to be a great merit (zechus) to eat something from the leftovers of a tzadik's meal. Many Hasidim claim that miracles can take place in merit of partaking of the shirayim, such as miraculous healing or blessings of wealth or piety. Hasidic songs, or niggunim, are sung with great gusto. The songs may at times be either joyous or solemnly meditative. The rebbe may teach words of Torah, often mystical passages from the Midrash, Zohar, and the Kabbalah during the tische. He may also tell Hasidic stories, parables, and history. He may also give religious commentary on current events and politics. Women do not sit with the men (because some communities of Orthodox Jews, especially Hasidim, are very strict about the gender separation) but they are often present to observe the tische from the ezras noshim ("women's section") in the main synagogue or hall where it is taking place. The women present do not sing aloud, and they generally do not receive the shirayim, although sometimes they do. A tische can vary in size from a handful to thousands of people. Large tischen are usually held in special rooms in the main building of a Hasidic movement. Sometimes they are held in the main synagogue. Around the holidays, when thousands of Hasidim who live in other cities or countries come to pray and visit with their Rebbe joining the Hasidim who live near the Rebbe and things can get very crowded, they are sometimes held in a large temporary structure. Small tischen are often conducted in private homes, particularly when a Hasidic Rebbe is visiting another community. As public events, non-Hasidic Jews and Hasidim of one rebbe may also visit the tische of another Rebbe. Non-Jews sometimes visit a tische as well, particularly dignitaries and politicians, during a weekday tish such as on Chol HaMoed. Occasions A tische takes place at the meals in honor of the Shabbat, Jewish holidays, yahrzeit ("annual memorial") for previous rebbes of that dynasty, as a seudas hoda'ah (meal of thanksgiving) to God for past salvations (such as escape from prisons or from the Holocaust), or some other seudas mitzvah. Some Hasidic movements hold a tische every Shabbat; others do so only on Jewish holidays. The time at which a tische can be held also differs. For example, Belzer Hasidim conduct their tische both late Friday night and on Saturday afternoon for Seudah Shlishit, while Gerrer Hasidim only have their tische on Saturday afternoon or early evening for Seudah Shlishit. A tische is usually also held on minor holidays such as Lag BaOmer, Hanukkah, Purim, Tu Bishvat, on the minor days (Chol Hamoed) of major festivals Sukkos and Pesach, and before and after the fast of Yom Kippur. Related affairs Botteh Sometimes, a Hasidic gathering similar to a tische is conducted without the presence of a Rebbe. This is called a botteh () in Yiddish or a shevet achim () in Hebrew. It is often led by a Rabbi who is not a Rebbe, such as a Rosh Yeshivah, Mashgiach Ruchani, or a Rebbe's son. Often, a botteh will be indistinguishable from a tische, for the respect that many Hasidim have for their Rebbe's son is often very close to the reverence for the Rebbe himself, as he is the assumed heir to the throne. Farbrengen Among Lubavitcher Hasidim, a gathering known as a farbrengen () is celebrated, similar to a tish. A farbrengen may be conducted with or without the presence of a Rebbe, and even with the presence of only a few Hasidim. At a farbrengen, zemiros are generally not sung (with the exception of the zemiros of the Arizal for each Sabbath meal), but rather only niggunim. References Hasidic Judaism Shabbat Yiddish words and phrases Meetings

3899771

https://en.wikipedia.org/wiki/Comet%20nucleus

Comet nucleus

The nucleus is the solid, central part of a comet, formerly termed a dirty snowball or an icy dirtball. A cometary nucleus is composed of rock, dust, and frozen gases. When heated by the Sun, the gases sublime and produce an atmosphere surrounding the nucleus known as the coma. The force exerted on the coma by the Sun's radiation pressure and solar wind cause an enormous tail to form, which points away from the Sun. A typical comet nucleus has an albedo of 0.04. This is blacker than coal, and may be caused by a covering of dust. Results from the Rosetta and Philae spacecraft show that the nucleus of 67P/Churyumov–Gerasimenko has no magnetic field, which suggests that magnetism may not have played a role in the early formation of planetesimals. Further, the ALICE spectrograph on Rosetta determined that electrons (within above the comet nucleus) produced from photoionization of water molecules by solar radiation, and not photons from the Sun as thought earlier, are responsible for the degradation of water and carbon dioxide molecules released from the comet nucleus into its coma. On 30 July 2015, scientists reported that the Philae spacecraft, that landed on comet 67P/Churyumov-Gerasimenko in November 2014, detected at least 16 organic compounds, of which four (including acetamide, acetone, methyl isocyanate and propionaldehyde) were detected for the first time on a comet. Paradigm Comet nuclei, at ~1 km to at times tens of kilometers, could not be resolved by telescopes. Even current giant telescopes would give just a few pixels on target, assuming nuclei were not obscured by comae when near Earth. An understanding of the nucleus, versus the phenomenon of the coma, had to be deduced, from multiple lines of evidence. "Flying sandbank" The "flying sandbank" model, first proposed in the late-1800s, posits a comet as a swarm of bodies, not a discrete object at all. Activity is the loss of both volatiles, and population members. This model was championed in midcentury by Raymond Lyttleton, along with an origin. As the Sun passed through interstellar nebulosity, material would clump in wake eddies. Some would be lost, but some would remain in heliocentric orbits. The weak capture explained long, eccentric, inclined comet orbits. Ices per se were lacking; volatiles were stored by adsorption on grains. "Dirty snowball" Beginning in the 1950s, Fred Lawrence Whipple published his "icy conglomerate" model. This was soon popularized as "dirty snowball." Comet orbits had been determined quite precisely, yet comets were at times recovered "off-schedule," by as much as days. Early comets could be explained by a "resisting medium"- such as "the aether", or the cumulative action of meteoroids against the front of the comet(s). But comets could return both early and late. Whipple argued that a gentle thrust from asymmetric emissions (now "nongravitational forces") better explained comet timing. This required that the emitter have cohesive strength- a single, solid nucleus with some proportion of volatiles. Lyttleton continued publishing flying-sandbank works as late as 1972. The death knell for the flying sandbank was Halley's Comet. Vega 2 and Giotto images showed a single body, emitting through a small number of jets. "Icy dirtball" It has been a long time since comet nuclei could be imagined as frozen snowballs. Whipple had already postulated a separate crust and interior. Before Halley's 1986 apparition, it appeared that an exposed ice surface would have some finite lifetime, even behind a coma. Halley's nucleus was predicted to be dark, not bright, due to preferential destruction/escape of gases, and retention of refractories. The term dust mantling has been in common use since more than 35 years. The Halley results exceeded even these- comets are not merely dark, but among the darkest objects in the Solar System Furthermore, prior dust estimates were severe undercounts. Both finer grains and larger pebbles appeared in spacecraft detectors, but not ground telescopes. The volatile fraction also included organics, not merely water and other gases. Dust-ice ratios appeared much closer than thought. Extremely low densities (0.1 to 0.5 g cm-3) were derived. The nucleus was still assumed to be majority-ice, perhaps overwhelmingly so. Modern theory Three rendezvous missions aside, Halley was one example. Its unfavorable trajectory also caused brief flybys at extreme speed, at one time. More frequent missions broadened the sample of targets, using more advanced instruments. By chance, events such as the breakups of Shoemaker-Levy 9 and Schwassmann-Wachmann 3 contributed to our understanding. Densities were confirmed as quite low, ~0.6 g cm3. Comets were highly porous, and fragile on micro- and macro-scales. Refractory-to-ice ratios are much higher, at least 3:1, possibly ~5:1, ~6:1, or more. This is a full reversal from the dirty snowball model. The Rosetta science team has coined the term "mineral organices," for minerals and organics with a minor fraction of ices. Manx comets, Damocloids, and active asteroids demonstrate that there may be no bright line separating the two categories of objects. Origin Comets, or their precursors, formed in the outer Solar System, possibly millions of years before planet formation. How and when comets formed is debated, with distinct implications for Solar System formation, dynamics, and geology. Three-dimensional computer simulations indicate the major structural features observed on cometary nuclei can be explained by pairwise low velocity accretion of weak cometesimals. The currently favored creation mechanism is that of the nebular hypothesis, which states that comets are probably a remnant of the original planetesimal "building blocks" from which the planets grew. Astronomers think that comets originate in the Oort cloud, the scattered disk, and the outer Main Belt. Size Most cometary nuclei are thought to be no more than about 16 kilometers (10 miles) across. The largest comets that have come inside the orbit of Saturn are 95P/Chiron (≈200 km), C/2002 VQ94 (LINEAR) (≈100 km), Comet of 1729 (≈100 km), Hale–Bopp (≈60 km), 29P (≈60 km), 109P/Swift–Tuttle (≈26 km), and 28P/Neujmin (≈21 km). The potato-shaped nucleus of Halley's comet (15 × 8 × 8 km) contains equal amounts of ice and dust. During a flyby in September 2001, the Deep Space 1 spacecraft observed the nucleus of Comet Borrelly and found it to be about half the size (8×4×4 km) of the nucleus of Halley's Comet. Borrelly's nucleus was also potato-shaped and had a dark black surface. Like Halley's Comet, Comet Borrelly only released gas from small areas where holes in the crust exposed the ice to sunlight. The nucleus of comet Hale–Bopp was estimated to be 60 ± 20 km in diameter. Hale-Bopp appeared bright to the unaided eye because its unusually large nucleus gave off a great deal of dust and gas. The nucleus of P/2007 R5 is probably only 100–200 meters in diameter. The largest centaurs (unstable, planet crossing, icy asteroids) are estimated to be 250 km to 300 km in diameter. Three of the largest would include 10199 Chariklo (258 km), 2060 Chiron (230 km), and (≈220 km). Known comets have been estimated to have an average density of 0.6 g/cm3. Below is a list of comets that have had estimated sizes, densities, and masses. Composition It was once thought that water-ice was the predominant constituent of the nucleus. In the dirty snowball model, dust is ejected when the ice retreats. Based on this, about 80% of the Halley's Comet nucleus would be water ice, and frozen carbon monoxide (CO) makes up another 15%. Much of the remainder is frozen carbon dioxide, methane, and ammonia. Scientists think that other comets are chemically similar to Halley's Comet. The nucleus of Halley's Comet is also an extremely dark black. Scientists think that the surface of the comet, and perhaps most other comets, is covered with a black crust of dust and rock that covers most of the ice. These comets release gas only when holes in this crust rotate toward the Sun, exposing the interior ice to the warming sunlight. This assumption was shown to be naive, starting at Halley. Coma composition does not represent nucleus composition, as activity selects for volatiles, and against refractories, including heavy organic fractions. Our understanding has evolved more toward mostly rock; recent estimates show that water is perhaps only 20-30% of the mass in typical nuclei. Instead, comets are predominantly organic materials and minerals. Data from Churyumov-Gerasimenko and Arrokoth, and laboratory experiments on accretion, suggest refractories-to-ices ratios less than 1 may not be possible. The composition of water vapor from Churyumov–Gerasimenko comet, as determined by the Rosetta mission, is substantially different from that found on Earth. The ratio of deuterium to hydrogen in the water from the comet was determined to be three times that found for terrestrial water. This makes it unlikely that water on Earth came from comets such as Churyumov–Gerasimenko. Organics "Missing Carbon" Structure On 67P/Churyumov–Gerasimenko comet, some of the resulting water vapour may escape from the nucleus, but 80% of it recondenses in layers beneath the surface. This observation implies that the thin ice-rich layers exposed close to the surface may be a consequence of cometary activity and evolution, and that global layering does not necessarily occur early in the comet's formation history. Measurements carried out by the Philae lander on 67P/Churyumov–Gerasimenko comet, indicate that the dust layer could be as much as thick. Beneath that is hard ice, or a mixture of ice and dust. Porosity appears to increase toward the center of the comet. While most scientists thought that all the evidence indicated that the structure of nuclei of comets is processed rubble piles of smaller ice planetesimals of a previous generation, the Rosetta mission dispelled the idea that comets are "rubble piles" of disparate material. The Rosetta mission indicated that comets may be "rubble piles" of disparate material. Data were not conclusive concerning the collisional environment during the formation and right afterwards. Splitting The nucleus of some comets may be fragile, a conclusion supported by the observation of comets splitting apart. Splitting comets include 3D/Biela in 1846, Shoemaker–Levy 9 in 1992, and 73P/Schwassmann–Wachmann from 1995 to 2006. Greek historian Ephorus reported that a comet split apart as far back as the winter of 372–373 BC. Comets are suspected of splitting due to thermal stress, internal gas pressure, or impact. Comets 42P/Neujmin and 53P/Van Biesbroeck appear to be fragments of a parent comet. Numerical integrations have shown that both comets had a rather close approach to Jupiter in January 1850, and that, before 1850, the two orbits were nearly identical. Albedo Cometary nuclei are among the darkest objects known to exist in the Solar System. The Giotto probe found that Comet Halley's nucleus reflects approximately 4% of the light that falls on it, and Deep Space 1 discovered that Comet Borrelly's surface reflects only 2.5–3.0% of the light that falls on it; by comparison, fresh asphalt reflects 7% of the light that falls on it. It is thought that complex organic compounds are the dark surface material. Solar heating drives off volatile compounds leaving behind heavy long-chain organics that tend to be very dark, like tar or crude oil. The very darkness of cometary surfaces allows them to absorb the heat necessary to drive their outgassing. Roughly six percent of the near-Earth asteroids are thought to be extinct nuclei of comets (see Extinct comets) which no longer experience outgassing. Two near-Earth asteroids with albedos this low include 14827 Hypnos and 3552 Don Quixote. Discovery and exploration The first relatively close mission to a comet nucleus was space probe Giotto. This was the first time a nucleus was imaged at such proximity, coming as near as 596 km. The data was a revelation, showing for the first time the jets, the low-albedo surface, and organic compounds. During its flyby, Giotto was hit at least 12,000 times by particles, including a 1-gram fragment that caused a temporary loss of communication with Darmstadt. Halley was calculated to be ejecting three tonnes of material per second from seven jets, causing it to wobble over long time periods. Comet Grigg–Skjellerup's nucleus was visited after Halley, with Giotto approaching 100–200 km. Results from the Rosetta and Philae spacecraft show that the nucleus of 67P/Churyumov–Gerasimenko has no magnetic field, which suggests that magnetism may not have played a role in the early formation of planetesimals. Further, the ALICE spectrograph on Rosetta determined that electrons (within above the comet nucleus) produced from photoionization of water molecules by solar radiation, and not photons from the Sun as thought earlier, are responsible for the degradation of water and carbon dioxide molecules released from the comet nucleus into its coma. Comets already visited are: Halley's Comet 26P/Grigg-Skjellerup Tempel 1 (also hit with impactor) 19P/Borrelly 81P/Wild 103P/Hartley C/2013 A1 (Siding Spring) -unplanned encounter with Mars spacecraft 67P/Churyumov–Gerasimenko (also landed on) See also Coma (cometary) Hypatia (stone) List of comets visited by spacecraft References External links Nucleus of Halley's Comet (15×8×8 km) Nucleus of Comet Wild 2 (5.5×4.0×3.3 km) International Comet Quarterly: Split Comets 67/P by Rosetta2 (ESA) Comets

3900801

https://en.wikipedia.org/wiki/71P/Clark

71P/Clark

71P/Clark is a periodic comet in the Solar System with an orbital period of 5.5 years. It was discovered by Michael Clark at Mount John University Observatory, New Zealand on 9 June 1973 with a brightness of apparent magnitude 13. Subsequently it has been observed in 1978, 1984, 1989, 1995, 2000, 2006, 2011 and 2017. The nucleus of the comet has a radius of 0.68 ± 0.04 kilometers, assuming a geometric albedo of 0.04, based on observations by Hubble Space Telescope, while observations by Keck indicate a radius of 1.305 km. See also List of numbered comets References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 71P/Clark – Seiichi Yoshida @ aerith.net Periodic comets 0071 Comets in 2011 Comets in 2017 19730609

3900976

https://en.wikipedia.org/wiki/73P/Schwassmann%E2%80%93Wachmann

73P/Schwassmann–Wachmann

73P/Schwassmann–Wachmann, also known as Schwassmann–Wachmann 3 or SW3 for short, is a periodic comet that has a 5.4 year orbital period and that has been actively disintegrating since 1995. When it came to perihelion (closest approach to the Sun) in March 2017, fragment 73P-BT was separating from the main fragment 73P-C. Fragments 73P-BU and 73P-BV were detected in July 2022. The main comet came to perihelion on 25 August 2022, when the comet was 0.97 AU from the Sun and 1 AU from Earth. It will be less than 80 degrees from the Sun from 25 May 2022 until August 2023. On 3 April 2025 it will make a modest approach of 0.3 AU to Jupiter. 73P will next come to perihelion on 23 December 2027 when it will be 0.92 AU from the Sun and on the far side of the Sun 1.9 AU from Earth. Comet Schwassmann–Wachmann 3 was one of the comets discovered by astronomers Arnold Schwassmann and Arno Arthur Wachmann, working at the Hamburg Observatory in Bergedorf, Germany. It began disintegrating on its re-entry to the inner Solar System in 1995, in a reaction triggered by the Sun's heating of the comet as it emerged from the colder regions of the outer Solar System. Comet 73P/Schwassmann–Wachmann is a parent body of meteor shower Tau Herculids and the 1995 break-up of the comet generated a modest meteor shower around 31 May 2022 4:00-5:00 UT that lasted a few hours. The comet was discovered as astronomers were exposing photographic plates in search of minor planets for a minor planet survey, on May 2, 1930. On 31 May 1930 the comet passed about from Earth. The comet was lost after its 1930 apparition as the 1935 apparition had poor viewing geometry, but was recovered in 1979. During perihelion in 1985, the comet was unobserved as it was on the far side of the Sun 1.9 AU from Earth. In 1990 the comet reached apparent magnitude 9 and was the best appearance since 1930. On 12 May 2006 the comet passed from Earth. During the 2011 perihelion passage the primary component 73P-C was recovered on 28 November 2010 near apparent magnitude 21.3; it came to perihelion on 16 October 2011. Schwassmann–Wachmann has an orbital period of 5.4 years and has an Earth-MOID of . At aphelion (farthest distance from the Sun) the comet often makes approaches to Jupiter as it did in 1965 and will in 2167. Schwassmann–Wachmann was originally estimated to have a pre-breakup nucleus diameter of approximately 2.2 km. In 2005 fragment C was estimated to be about 1 km in diameter. Breakup In September 1995, 73P began to disintegrate. It was seen to break into four large pieces labeled 73P-A, B, C and D. As of March 2006, at least eight fragments were known: B, C, G, H, J, L, M and N. On April 18, 2006, the Hubble Space Telescope recorded dozens of pieces of fragments B and G. It appears that the comet may eventually disintegrate completely and cease to be observable (as did 3D/Biela in the 19th century), in which case its designation would change from 73P to 73D. In May 2006, it was known to have split into at least 66 separate objects. In April 2006, fragment C was the largest and the presumed principal remnant of the original nucleus. The fragments passed Earth in May 2006, with the comet coming nearest to Earth on May 12 at a distance of , a close pass in astronomical terms though with no significant threat of debris–Earth collision. With a 34-day observation arc fragment 73P-T was known to pass Earth on May 16 at roughly a distance of . In 1930 when the comet passed Earth that close, there was a meteor shower on June 9 with as many as 100 meteors per hour. Analysis by P. A. Wiegert et al. suggested that a recurrence of that spectacle was unlikely. Over many decades the fragments of 73P from 1995 and 2006 will disperse over the orbital path of 73P as they are all moving at a slightly different speed. Known fragments of 73P have orbital periods of 4.7 years (73P-AJ) to 6.1 years (73P-Y). While the main fragment of 73P came to perihelion (closest approach to the Sun) on 25 August 2022 when it was 1 AU from Earth, fragment 73P-Y (with a short 34-day observation arc) had a best-fit of being near the orbit of Jupiter about from Earth. The non-primary fragment 73P-BT which has an observation arc of 250 days from February 2017 to October 2017 and (if it had survived) was expected to come to perihelion on 26 August 2022. On 23 July 2022 fragments JD001 (73P-BU) and JD002 (73P-BV) were detected and came to perihelion on 24 August 2022. Three additional fragments "BW, BX, and BY" that were discovered in mid-August were announced on 2 September 2022. 73P-BV had a 22-day observation arc giving it the longest observation arc of the five fragments discovered in 2022. The comet was to have been visited by the CONTOUR comet nucleus probe on June 18, 2006, but contact with the probe was lost on August 15, 2002 when it fired its Star 30BP solid rocket motor to inject itself into solar orbit. Image gallery References External links 73P, bt fragment via Virtual Telescope Project 73P at Kronk's Cometography Mini-comets approaching Earth (NASA) Sky and Telescope article 73P/Schwassmann–Wachmann at ESA/Hubble 73P/Schwassmann–Wachmann 3 (2022) aerith.net 73P-c Lightcurve (Artyom Novichonok) Periodic comets 073P 0073 Split comets Articles containing video clips Comets in 2011 Comets in 2017 Comets in 2022 19300502 Meteor shower progenitors

3909680

https://en.wikipedia.org/wiki/Solar%20Dynamics%20Observatory

Solar Dynamics Observatory

The Solar Dynamics Observatory (SDO) is a NASA mission which has been observing the Sun since 2010. Launched on 11 February 2010, the observatory is part of the Living With a Star (LWS) program. The goal of the LWS program is to develop the scientific understanding necessary to effectively address those aspects of the connected Sun–Earth system directly affecting life on Earth and its society. The goal of the SDO is to understand the influence of the Sun on the Earth and near-Earth space by studying the solar atmosphere on small scales of space and time and in many wavelengths simultaneously. SDO has been investigating how the Sun's magnetic field is generated and structured, how this stored magnetic energy is converted and released into the heliosphere and geospace in the form of solar wind, energetic particles, and variations in the solar irradiance. General The SDO spacecraft was developed at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and launched on 11 February 2010, from Cape Canaveral Air Force Station (CCAFS). The primary mission lasted five years and three months, with expendables expected to last at least ten years. Some consider SDO to be a follow-on mission to the Solar and Heliospheric Observatory (SOHO). SDO is a three-axis stabilized spacecraft, with two solar arrays, and two high-gain antennas, in an inclined geosynchronous orbit around Earth. The spacecraft includes three instruments: the Extreme Ultraviolet Variability Experiment (EVE) built in partnership with the University of Colorado Boulder's Laboratory for Atmospheric and Space Physics (LASP), the Helioseismic and Magnetic Imager (HMI) built in partnership with Stanford University, and the Atmospheric Imaging Assembly (AIA) built in partnership with the Lockheed Martin Solar and Astrophysics Laboratory (LMSAL). Data which is collected by the craft is made available as soon as possible, after it is received. As of February 2020, SDO is expected to remain operational until 2030. Instruments Helioseismic and Magnetic Imager (HMI) The Helioseismic and Magnetic Imager (HMI), led from Stanford University in Stanford, California, studies solar variability and characterizes the Sun's interior and the various components of magnetic activity. HMI takes high-resolution measurements of the longitudinal and vector magnetic field over the entire visible solar disk thus extending the capabilities of SOHO's MDI instrument. HMI produces data to determine the interior sources and mechanisms of solar variability and how the physical processes inside the Sun are related to surface magnetic field and activity. It also produces data to enable estimates of the coronal magnetic field for studies of variability in the extended solar atmosphere. HMI observations will enable establishing the relationships between the internal dynamics and magnetic activity in order to understand solar variability and its effects. Extreme Ultraviolet Variability Experiment (EVE) The Extreme Ultraviolet Variability Experiment (EVE) measures the Sun's extreme ultraviolet irradiance with improved spectral resolution, "temporal cadence", accuracy, and precision over preceding measurements made by TIMED SEE, SOHO, and SORCE XPS. The instrument incorporates physics-based models in order to further scientific understanding of the relationship between solar EUV variations and magnetic variation changes in the Sun. The Sun's output of energetic extreme ultraviolet photons is primarily what heats the Earth's upper atmosphere and creates the ionosphere. Solar EUV radiation output undergoes constant changes, both moment to moment and over the Sun's 11-year solar cycle, and these changes are important to understand because they have a significant impact on atmospheric heating, satellite drag, and communications system degradation, including disruption of the Global Positioning System. The EVE instrument package was built by the University of Colorado Boulder's Laboratory for Atmospheric and Space Physics (LASP), with Dr. Tom Woods as principal investigator, and was delivered to NASA Goddard Space Flight Center on 7 September 2007. The instrument provides improvements of up to 70% in spectral resolution measurements in the wavelengths below 30 nm, and a 30% improvement in "time cadence" by taking measurements every 10 seconds over a 100% duty cycle. Atmospheric Imaging Assembly (AIA) The Atmospheric Imaging Assembly (AIA), led from the Lockheed Martin Solar and Astrophysics Laboratory (LMSAL), provides continuous full-disk observations of the solar chromosphere and corona in seven extreme ultraviolet (EUV) channels, spanning a temperature range from approximately 20,000 Kelvin to in excess of 20 million Kelvin. The 12-second cadence of the image stream with 4096 by 4096 pixel images at 0.6 arcsec/pixel provides unprecedented views of the various phenomena that occur within the evolving solar outer atmosphere. The AIA science investigation is led by LMSAL, which also operates the instrument and – jointly with Stanford University – runs the Joint Science Operations Center from which all of the data are served to the worldwide scientific community, as well as the general public. LMSAL designed the overall instrumentation and led its development and integration. The four telescopes providing the individual light feeds for the instrument were designed and built at the Smithsonian Astrophysical Observatory (SAO). Since beginning its operational phase on 1 May 2010, AIA has operated successfully with unprecedented EUV image quality. Photographs of the Sun in these various regions of the spectrum can be seen at NASA's SDO Data website. Images and movies of the Sun seen on any day of the mission, including within the last half-hour, can be found at The Sun Today. Communications SDO down-links science data (K-band) from its two onboard high-gain antennas, and telemetry (S-band) from its two onboard omnidirectional antennas. The ground station consists of two dedicated (redundant) 18-meter radio antennas in White Sands Missile Range, New Mexico, constructed specifically for SDO. Mission controllers operate the spacecraft remotely from the Mission Operations Center at NASA Goddard Space Flight Center. The combined data rate is about 130 Mbit/s (150 Mbit/s with overhead, or 300 Msymbols/s with rate 1/2 convolutional encoding), and the craft generates approximately 1.5 Terabytes of data per day (equivalent to downloading around 500,000 songs). Launch NASA's Launch Services Program at Kennedy Space Center managed the payload integration and launch. The SDO launched from Cape Canaveral Space Launch Complex 41 (SLC-41), utilizing an Atlas V-401 rocket with a RD-180 powered Common Core Booster, which has been developed to meet the Evolved Expendable Launch Vehicle (EELV) program requirements. Orbit After launch, the spacecraft was placed into an orbit around the Earth with an initial perigee of about . SDO then underwent a series of orbit-raising maneuvers which adjusted its orbit until the spacecraft reached its planned circular, geosynchronous orbit at an altitude of , at 102° West longitude, inclined at 28.5°. This orbit was chosen to allow 24/7 communications to/from the fixed ground station, and to minimise solar eclipses to about an hour a day for only a few weeks a year. Sun dog phenomenon Moments after launch, SDO's Atlas V rocket penetrated a cirrus cloud which created visible shock waves in the sky and destroyed the alignment of ice crystals that were forming a sun dog visible to onlookers. Mission mascot - Camilla Camilla Corona is a rubber chicken (similar to a children's toy), and is the mission mascot for SDO. It is part of the Education and public outreach team and assists with various functions to help educate the public, mainly children, about the SDO mission, facts about the Sun and Space weather. Camilla also assists in cross-informing the public about other NASA missions and space related projects. Camilla Corona SDO uses social media to interact with fans. Image gallery Stamps NASA's images of the Sun's dynamic and dazzling beauty have captivated the attention of millions. In 2021, the U.S. Postal Service is showcasing the Sun's many faces with a series of Sun Science forever stamps that show images of solar activity captured by NASA's Solar Dynamics Observatory (SDO). "I have been a stamp collector all my life and I can't wait to see NASA science highlighted in this way", said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate (SMD) in Washington, D.C. "I feel that the natural world around us is as beautiful as art, and it is inspiring to be able to share the import and excitement of studying the Sun with people around the country". The 20-stamp set features ten images that celebrate the science behind NASA's ongoing exploration of our nearest star. The images display common events on the Sun, such as solar flares, sunspots and coronal loops. SDO has kept a constant eye on the Sun for over a decade. Outfitted with equipment to capture images of the Sun in multiple wavelengths of visible, ultraviolet, and extreme ultraviolet light, SDO has gathered hundreds of millions of images during its tenure to help scientists learn about how our star works and how its constantly churning magnetic fields create the solar activity we see. That solar activity can drive space weather closer to Earth that can interfere with technology and radio communications in space. In addition to this immediate relevancy to our high-tech daily lives, the study of the Sun and its influence on the planets and space surrounding it – a field of research known as heliophysics – holds profound implications for the understanding of our Solar System and the thousands of solar systems that have been discovered beyond our own. As our closest star, the Sun is the only nearby star that humans are able to study in great detail, making it a vital source of data. See also Heliophysics Advanced Composition Explorer Parker Solar Probe Radiation Belt Storm Probes (Van Allen Probes) Richard R. Fisher Solar and Heliospheric Observatory (SOHO) STEREO (Solar TErrestrial RElations Observatory), launched 2006, 1 of 2 spacecraft still operational. Wind (spacecraft), launched 1994, still operational. List of heliophysics missions References External links Solar Dynamics Observatory (SDO) mission website Where is the Solar Dynamics Observatory (SDO) right now? SDO Outreach Material, HELAS Inbound SOHO comet disintegrates as seen in SDO AIA images (Cometal 14 July 2011) History of SDO patch, Facebook Sunspot Database based on SDO (HMI) satellite observations from 2010 to nowadays with the newest data. () Album of images and videos by Seán Doran, based on SDO imagery, and a longer (24 min.) YouTube video: Sun Dance SDO 5-year timelapse video of the Sun SDO 10-year timelapse video of the Sun Instruments Extreme Ultraviolet Variability Experiment (EVE) , University of Colorado ATMOSPHERIC IMAGING ASSEMBLY (AIA), Lockheed Martin Helioseismic and Magnetic Imager (HMI), Stanford Joint Science Operations Center – Science Data Processing HMI – AIA Space probes launched in 2010 NASA space probes Living With a Star Missions to the Sun Solar space observatories Solar telescopes Space weather Articles containing video clips Spacecraft launched by Atlas rockets

3910239

https://en.wikipedia.org/wiki/Masten%20Space%20Systems

Masten Space Systems

Masten Space Systems was an aerospace manufacturer startup company in Mojave, California (formerly in Santa Clara, California) that was developing a line of vertical takeoff, vertical landing (VTVL) rockets, initially for uncrewed research sub-orbital spaceflights and eventually intended to support robotic orbital spaceflight launches. In 2020, NASA awarded Masten a contract for a lunar lander mission; NASA was to pay Masten US$75.9 million for Masten to build and launch a lander called XL-1 to take NASA and other customer payloads to the south pole of the Moon. Masten Mission One would have been Masten's first space flight; it was scheduled for launch in November 2023. The company filed for Chapter 11 bankruptcy on July 2022, and was later acquired by Astrobotic Technology in September 2022. Overview Masten Space Systems was a Mojave, California based rocket company that was developing a line of reusable VTVL spacecraft, and related rocket propulsion hardware. Masten Space Systems competed in the NASA and Northrop Grumman Lunar Lander Challenge X Prize in 2009, winning the level one second prize of US$150,000 and the level two first prize of US$1,000,000. On 2 November 2009, it was announced that Masten Space Systems had won first place in the level two category, with Armadillo Aerospace coming in second. Masten Space Systems was selected for the Lunar CATALYST initiative of the NASA on 30 April 2014. Masten was accepted to make a bid for NASA's Commercial Lunar Payload Services (CLPS) program on 29 November 2018. Masten proposed to NASA that Masten would develop a lunar lander called XL-1 to take scientific payload to the Moon. NASA accepted this proposal to be assessed, whether it would be developed or not, as part of the CLPS program. NASA would later choose which of the bids made for CLPS program by the various companies eligible to bid for CLPS the agency would eventually fund for development. On 8 April 2020, it was announced that NASA had selected Masten's CLPS bid to be developed. NASA awarded Masten a $75.9 million contract to build, launch, land and operate their XL-1 Moon lander. The lander would take payload from NASA and other customers to the south pole of the Moon. Masten Mission One, the first XL-1 lander, was scheduled for launch in November 2023. Masten Space Systems filed for Chapter 11 bankruptcy on July 28, 2022. The company's assets were purchased for US$4.5 million by Astrobotic Technology on September 8, 2022, who continues to operate the company's test vehicles. Xombie Masten's Xombie (model XA-0.1B) won the second prize in the Level One competition of the Lunar Lander Challenge on 7 October 2009 with an average landing accuracy of . The primary goal of these two airframes was to demonstrate stable, controlled flight using a GN&C system developed in-house at Masten. XA-0.1B originally featured four engines with thrust, but was converted in Spring 2009 to be powered by one engine of thrust. By October 2009, the regeneratively cooled isopropyl alcohol and liquid oxygen rocket engine was running at around . XA-0.1B, nicknamed "Xombie", first flew free of tether 19 September 2009, and qualified for the Lunar Lander Challenge Level One second prize of $150,000 on 7 October 2009. In October 2016, NASA reported using Xombie to test the Landing Vision System (LVS), as part of the Autonomous Descent and Ascent Powered-flight Testbed (ADAPT) experimental technologies, for the Mars 2020 mission landing. , Xombie had flown 224 times. Xoie Masten's Xoie (model XA-0.1E) won the Level Two prize of the Lunar Lander Challenge on October 30, 2009. They beat Armadillo Aerospace by just a bit more than of total landing accuracy, with an average accuracy of about on the two landings in the round-trip competition flight. Xoie had an aluminum frame and featured a version of Masten's thrust engine that produced around of thrust. "Xoie", as the craft was nicknamed, qualified for the Lunar Lander Challenge level two on October 30, 2009. Xaero The Xaero reusable launch vehicle was a vertical-takeoff, vertical-landing (VTVL) rocket which was being developed by Masten in 2010–2011. It was proposed to NASA as a potential suborbital reusable launch vehicle (sRLV) for carrying research payloads under NASA's Flight Opportunities Program (initially known as the Commercial Reusable Suborbital Research/CRuSR program), projecting altitude in initial flights of five to six minutes duration, while carrying a research payload. It was propelled by the Cyclops-AL-3 rocket engine burning isopropyl alcohol and liquid oxygen. The first Xaero test vehicle flew 110 test flights before being destroyed in its 111th flight. During the record-setting flight on 11 September 2012, an engine valve stuck open during descent, and this was sensed by the control system. As designed, the flight termination system was triggered, destroying the vehicle before it could create a range safety problem. The final test flight was intended to test the vehicle at higher wind loads and altitudes, flying to an altitude of one kilometer while testing the flight controls at the higher ascent and descent velocities before returning to a precise landing point. The ascent and initial portion of the descent was nominal, prior to the stuck throttle valve which resulted in the termination of the flight prior to the planned precision landing. Xaero-B Xaero-B was a follow-up to Xaero with the ability to reach altitude with engine on throughout. Xaero-B was between 15 and 16 feet tall where Xaero was 12 feet tall. Xaero-B performed hot-fire testing and test flights. It would have been used for the bulk of research flights up to initial altitudes between to . The vehicle has now been retired due to damage on a test flight in April 2017. It flew 75 times. Xodiac The Xodiac was a VTVL rocket introduced in 2016. It featured pressure-fed LOX/IPA propellant, and a regeneratively cooled engine. Flights could simulate landing on the Moon or Mars. Video of Xodiac performing in-flight air flow tests Tuft strings. Xogdor Xogdor was a VTVL vehicle that Masten planned to introduce in 2023. As the sixth VTVL testbed developed at Masten, Xogdor would have improved upon the work done with Xodiac and tested descent and landing technologies at speeds up to . Xeus Xeus (pronounced Zeus) was a vertical-landing, vertical-takeoff lunar lander demonstrator. Xeus consisted of a Centaur upper stage (from United Launch Alliance) with RL-10 main engine to which four Katana vertical thrusters have been added. Production Xeus was estimated to be able to land on the Moon with up to 14 tonnes (revised to 10 tonnes) payload when using the expendable version or 5 tonnes payload when using the reusable version. The damaged Centaur on the demonstrator Xeus limited it to Earth flights. The production versions would have to have been manufacturing fault free and certified for space operations. Human rating might also have been needed. United Launch Alliance, supplier of the Centaur, referred to Xeus as an abbreviation for eXperimental Enhanced Upper Stage. Further details of the proposed design were given in the paper "Experimental Enhanced Upper Stage (XEUS): An affordable large lander system". Each of the Katanas used on a Xeus lander were likely to produce when performing a horizontal touchdown. In December 2012, Masten demonstrated their all-aluminum regeneratively-cooled engine, the KA6A. The talk in this video announced the Xeus and also showed NASA's Space Exploration Vehicle rover with its two astronauts as a possible payload for the XEUS. On 30 April 2014, the NASA announced that Masten Space Systems was one of the three companies selected for the Lunar CATALYST initiative. NASA signed an unfunded Space Act Agreement (SAA) with Masten in September 2014. The SAA lasts until August 2017, has 22 milestones and calls for "End-to-end demonstration of hardware and software that enables a commercial lander on the Moon." In December 2015, United Launch Alliance (ULA) were planning to upgrade the XEUS's main body from a Centaur Upper Stage to the Advanced Cryogenic Evolved Stage (ACES) which they were developing, significantly increasing the payload. Masten Space intended to incorporate experience from developing the XL family of cargo landers into the XEUS family of landers. In August 2016, ULA's president and CEO said ULA intended to human rate both the Vulcan and ACES. XEUS was cancelled in July 2018. XL-1 The XL-1 was a small cargo lunar lander that Masten was developing as part of the Lunar CATALYST program (SAAM ID 18250). When powered by MXP-351 the XL-1 was designed to land payloads onto the surface of the Moon. As of August 2017, Masten Space expected the XL-1 to have four main engines which were being prototyped on the XL-1T and a wet mass of about . On 11 October 2016, Masten Space Tweeted a video showing the test firing of its new bi-propellant combination, internally called MXP-351. The test used an existing engine with an experimental injector, the first 'Machete', producing thrust. Development of their 3D printed regen lunar engine that would use MXP-351 to land on the Moon continued. , a thrust version of Machete for the terrestrial testbed of the lander, dubbed XL-1T, was being manufactured. In October 2017, NASA extended the Lunar CATALYST agreement for 2 years. On 29 November 2018, it was announced that Masten was eligible to bid at a Commercial Lunar Payload Services (CLPS) contract by NASA. Should the proposal be accepted by NASA to be built, the landing to Moon would be no earlier than 2021. On 8 April 2020, NASA selected Masten to deliver eight payloads – with nine science and technology instruments – to the South Pole of the Moon in 2022 with the XL-1 lander. Masten would also operate the payloads, helping to lay the foundation for human expeditions to the lunar surface beginning in 2024. The payloads, which included instruments to assess the composition of the lunar surface, test precision landing technologies, and evaluate the radiation on the Moon, were being delivered under NASA's Commercial Lunar Payload Services (CLPS) initiative as part of the agency's Artemis program. The US$75.9 million award included end-to-end services for delivery of the instruments, including payload integration, launch from Earth, landing on the surface of the Moon, and operation for at least 12 days. The payloads had predominantly been developed through two recent NASA Provided Lunar Payloads (NPLP) and Lunar Surface Instrument and Technology Payloads (LSITP) solicitations. On 26 August 2020, Masten announced that the first XL-1 mission, Masten Mission One, would be launched by SpaceX, although it was not at the time publicly known which SpaceX launch vehicle it would fly on. On 23 June 2021, Masten announced that the launch of Masten Mission One had been delayed to November 2023 due to COVID-19 pandemic related issues. XL-1T The XL-1T was a (T)errestrial technology and process demonstrator for the XL-1 and XEUS. A terrestrial flying test-bed was being used since lack of vehicle access to lunar landers after launch would make Masten's incremental design and test development methodology difficult and very expensive. Like the XL-1, the XL-1T was under development in partnership with NASA CATALYST (SAAM ID 18250). The XL-1T was expected to have a dry mass of 588.93 kg and a wet mass of 1270.68 kg which was less than the XL-1. The vehicle had 4 off Machete 4400 N main engines able to throttle between 25% and 100% (4:1). The propellant was MPX-351. Yaw and pitch were controlled by differential throttling. There were 4 off 22 N ACS thrusters to control roll. Many characteristics of the XL-1T were deliberately made similar to the XL-1. These included multi-engine architecture, avionics, software, fuel, movement of inertia, slosh management, and mission design tools. XS-1 Masten was awarded a contract from DARPA to develop the XS-1 experimental spaceplane. Project ended as DARPA awarded the Phase 2 to Boeing. Other products and services In addition to its line of vehicles, Masten Space Systems was offering its internally developed igniters and engines commercially to interested and qualified parties. Masten also had stated its intent at multiple conferences to participate in technology maturation and proof of concept projects. Broadsword Broadsword was a methane/liquid oxygen rocket engine Masten Space Systems was developing for the US government. Advanced manufacturing techniques would permit the engine to be used to provide a lower-cost reusable launch service for the growing CubeSat and smallsat launch market. The prototype engine took 1.5 months to construct and was made of aluminium. The engine consisted of 3 parts that were bolted together. The engine used an expander cycle and was planned to produce with a bell extension in vacuum. The development of a technology demonstration unit was completed in September 2016. The hot-fire test campaign concluded with the demonstration of six successful engine starts. , a second development unit containing enhancements was being developed for NASA under the Tipping Point program with the aim of being flight qualified. Cutlass Cutlass was a methane/liquid oxygen rocket engine Masten Space Systems was developing for the US government. Built using aluminium alloy via additive manufacturing techniques. Cutlass evolved into a low cost expendable upper stage engine using a gas generator cycle. A Phase 2 SBIR grant was not awarded so development was put on hold. Katana Katana class engines were designed to produce up to of thrust and to be regeneratively cooled. They were designed for indefinite runtime and good throttle response. A video of the all aluminium Katana KA6A Regen 2800 lbf engine's shake down test burning LOX/IPA (Isopropyl alcohol). Machete Machete was the name for a family of throttleable rocket engine designs Masten Space Systems was developing to permit their XL-1 lunar lander to land on the Moon. The Machete rocket engines burned the nontoxic storable hypergolic propellant combination MXP-351. The first Machete had an experimental injector design that was used to test MXP-351 in 2016, producing a thrust of 225 lbf. , Masten was modifying the design to make the engines additively-manufactured with regeneratively-cooled thrust chambers. Machete engines were being scaled up to produce 1000 lb thrust for a terrestrial test-bed version dubbed (XL-1T). MXP-351 MXP-351 was Masten Space's internal name for a self-igniting bipropellant combination invented to fuel its small lunar landers. Unlike the traditional NTO/MMH bipropellant, the two propellant chemicals in MXP-351 were safer to handle because they are nontoxic. The bipropellant could also be stored at room temperatures, unlike liquid oxygen and liquid hydrogen. The hypergolic combination had an ISP of 322 seconds. The storage life of MXP-351 before use was undergoing long-term studies but was expected to be a few years. The reduced operation constraints might have permitted a reduction in recurring operating costs. Masten Space used similar precautions when handling MXP-351 to those used for HTP (High-Test Peroxide). These included wearing splash protection clothing plus a simple chemical respirator. They claimed that spills could be rectified by diluting with water and rinsing away. Masten Mission One Masten Space Systems was to launch a lunar lander mission called Masten Mission One or MM1 in November 2023, using a SpaceX Falcon 9 or Falcon Heavy launch vehicle. It was to have a suite of payloads for NASA. See also References External links Masten Space Systems – Company homepage Masten YouTube – Company video at YouTube Masten/NASA Space Act Agreement - Amended September 2017 Covers XL-1, XL-1T and XEUS Mojave Air and Space Port Private spaceflight companies Rocket engine manufacturers of the United States Vehicle manufacturing companies established in 2004 Commercial Lunar Payload Services Companies that filed for Chapter 11 bankruptcy in 2022

3910926

https://en.wikipedia.org/wiki/Coat%20of%20arms%20of%20the%20British%20Indian%20Ocean%20Territory

Coat of arms of the British Indian Ocean Territory

The coat of arms of the British Indian Ocean Territory was granted in 1990 on the 25th anniversary of the territory's establishment. The centrepiece of the arms, the shield, bears a palm tree and St. Edward's Crown on a base of three white wavy lines representing the ocean, a sun in splendour in the upper-left corner, and the Union Flag in a chief at the top. Two sea turtles are used as supporters (a hawksbill turtle and a green turtle), representing the local native wildlife. The crest comprises a naval crown through which rises a red tower bearing the territory's flag; there is no helm or mantling. The motto is In tutela nostra Limuria, Latin for “Limuria is in our charge/trust”. This latinised name refers to the non-existent continent of Lemuria, once thought to occupy the Indian Ocean. The palm tree and royal crown also feature in the flag of the British Indian Ocean Territory. See also Gallery of coats of arms of the United Kingdom and dependencies References British Indian Ocean Territory British Indian Ocean Territory British Indian Ocean Territory culture British Indian Ocean Territory British Indian Ocean Territory British Indian Ocean Territory British Indian Ocean Territory British Indian Ocean Territory British Indian Ocean Territory British Indian Ocean Territory British Indian Ocean Territory

3911092

https://en.wikipedia.org/wiki/Sydney%20Observatory

Sydney Observatory

The Sydney Observatory is a heritage-listed meteorological station, astronomical observatory, function venue, science museum, and education facility located on Observatory Hill at Upper Fort Street, in the inner city Sydney suburb of Millers Point in the City of Sydney local government area of New South Wales, Australia. It was designed by William Weaver (plans) and Alexander Dawson (supervision) and built from 1857 to 1859 by Charles Bingemann & Ebenezer Dewar. It is also known as The Sydney Observatory; Observatory; Fort Phillip; Windmill Hill; and Flagstaff Hill. It was added to the New South Wales State Heritage Register on 22 December 2000. The site was formerly a defence fort, semaphore station, time ball station, meteorological station, observatory and windmills. The site evolved from a fort built on 'Windmill Hill' in the early 19th century to an observatory during the nineteenth century. It is now a working museum where evening visitors can observe the stars and planets through a modern Schmidt-Cassegrain telescope and an historic refractor telescope built in 1874, the oldest telescope in Australia in regular use. History Early use of the site The site of the Sydney Observatory has been a significant place in Sydney and has undergone a number of name changes. It was known as Windmill Hill in the 1790s when it was the site of the first windmill. After 1804 references are made to it as Fort Phillip or Citadel Hill, referring to the construction, but never completion, of a citadel on the site at Governor King's instruction for use in the case of an insurrection in Sydney. This was prompted by an influx of "Death or Liberty" Boys after the abortive 1798 uprising in Ireland, some of whom he believed to be of the most desperate character and cause for constant suspicion. Construction began but the citadel was not completed until Bligh had been installed in office. There were further discussions about a citadel during the Macquarie period but nothing eventuated beyond a half built powder magazine, Francis Greenway's first work after his appointment as civil architect in 1815. In 1797, early on during the European settlement of New South Wales, Australia, a windmill was built on the hill above the first settlement. Within ten years the windmill had deteriorated to the point of being useless; the canvas sails were stolen, a storm damaged the machinery, and already by 1800 the foundations were giving way. The name of Millers Point remembers this early land use. In 1803, Fort Philip was built on the site under the direction of Governor Hunter to defend the new settlement against a possible attack by the French and also from rebellious convicts. The fort was never required to be used for any such purposes. In 1825 the eastern wall of the fort was converted to a signal station. Flags were used to send messages to ships in the harbour and to the signal station on the South Head of the harbour. The site was known as Flagstaff Hill during and after the Macquarie era. A flagstaff had been erected on the site by 1811. Flag signalling was a cumbersome process and Commissioner Bigge advised Macquarie that it was expedient to erect a semaphore at South Head and Fort Phillip. The flag and semaphore were used for signalling in a variety of combinations. Observatory An early observatory was established in 1788 by William Dawes on Dawes Point, at the foot of Observatory Hill, in an ultimately unsuccessful attempt to observe in 1790 the return of a comet suggested by Edmond Halley (not Halley's Comet but a different one). In 1848, a new signal station was built by the Colonial Architect, Mortimer Lewis, on top of the fort wall on Windmill Hill. At the instigation of the Governor, Sir William Denison, it was agreed seven years later to build a full observatory next to the signal station. The first Government Astronomer, William Scott, was appointed in 1856, and work on the new observatory was completed in 1858. The most important role of the observatory was to provide time through the time-ball tower. Every day at exactly 1.00 pm, the time-ball on top of the tower would drop to signal the correct time to the city and harbour below. At the same time a cannon on Dawes Point was fired, later the cannon was moved to Fort Denison. The first time-ball was dropped at noon on 5 June 1858. Soon after the drop was rescheduled to one o'clock. The time-ball is still dropped daily at 1pm using the original mechanism, but with the aid of an electric motor, not as in the early days when the ball was raised manually. After the federation of Australia in 1901, meteorology became a function for the Commonwealth Government from 1908, while the observatory continued its astronomical role. The observatory continued to contribute observations to The astrographic catalogue, kept time and provided information to the public. For example, each day the observatory supplied Sydney newspapers with the rising and setting times of the sun, moon and planets. A proposal to close the observatory in 1926 was narrowly avoided, but, by the mid-1970s, the increasing problems of air pollution and city light made work at the observatory more and more difficult. In 1982, the NSW Government decided that Sydney Observatory was to be converted into a museum of astronomy and related fields as part of what is now the Powerhouse Museum. In November 1821 Governor Brisbane arrived with a set of astronomical instruments, a plan for an observatory and two personal employees with astronomical expertise - Charles Rumker and James Dunlop. Brisbane set up an observatory at the Governor's residence in Parramatta. Problems developed between Brisbane and Rumker. Rumker lost his position and it was not until Brisbane had been recalled that Rumker was reinstated by the Colonial Secretary. The following year Governor Darling, the new Governor, appointed Rumker as Government Astronomer, the first to hold the title in Australia. In 1831 Dunlop was appointed Superintendent at the observatory, Rumker again losing his position while on a visit to London. Brisbane's instruments remained at Parramatta when he left and they were used in that observatory until it was closed in 1847. The recommendation for the closure came from a commission appointed by Governor Fitzroy at the prompting of London. Dunlop had become increasingly frail and negligent and the Parramatta observatory had fallen into decay. The instruments were placed in ordnance storage at the urge of Phillip Parker King, a leading astronomer in Australia. Construction of an observatory King argued that a government observatory should be set up, and not just the suggested time ball. King's preference for Fort Phillip to be the site was eventually accepted. In the eight years from Edmund Blacket's modest 1850 plan for the time ball observatory until its completion, the plans underwent progressive enlargement. The 1850 plan was a room for a transit telescope and timekeeping apparatus with a small ante-room. In 1851 an enlarged version was presented to the Colonial Secretary but it had no time ball tower, because neither King or Blacket, the Colonial Architect, knew how it worked. The need for an Observer's dwelling was noted. Plans were redrawn in the next couple of years. When Blacket resigned in 1854 to take on the design and supervision of construction of The University of Sydney, plans were underway for an observatory that would be both functional and of architectural quality. Blacket's successor, William Weaver, replaced him on the observatory project. Weaver was appointed Colonial Architect in October 1854. Correspondence from him to Blacket in the early years indicates that Weaver was much happier in direct supervision of works than performing the duties of his desk-bound role. As head of an over-loaded department, he complained: A Select Committee on the Colonial Architect's Department in August 1855 questioned an overpayment to the stonemasonry contractor of the Dead House at Circular Quay and accused him of defrauding the Government. Weaver, as head of the Department, was accused of negligence for paying him and subsequently submitted his resignation in apparent disgust. Weaver was only 18 months as Colonial Architect and of the two major architectural works to come from his Department during his term in office, the Government Printing Office at the corner of Phillip and Bent Streets no longer stands and the Sydney Observatory has been generally attributed to his successor. In fact, Sir William Denison approved Weaver's plans "for an Observatory and Astronomical resicence" in August 1855 after some specifications supplied by Denison had been incorporated. When building commenced a year later the new Colonial Architect Alexander Dawson adopted those plans. Little more was done until the arrival of Sir William Denison as Governor General in January 1855. Denison saw an observatory as an important addition to the colony. As a result, the allocated to the time ball and building was augmented by an additional vote of for a complete observatory and Denison wrote to the Astronomer Royal asking him to find a competent astronomer. Plans and estimates were submitted in August 1855 but Denison decided to defer the final decision on the site and design until the arrival of the astronomer. Alexander Dawson replaced Weaver as Colonial Architect in April 1856 and the new Government Astronomer, Reverend William Scott, M.A., arrived with his family in October that year. Tenders for the construction were advertised in February 1857. The successful tenderers were Charles Bingemenn and Ebenezer Dewar. The plans used appear to have been the work of Dawson rather than those of his predecessors, there being numerous references by Scott to consultations with the Colonial Architect on the design of the building. Extra work was approved after Bingemann and Dewar won their tender. This included the addition of a telescope dome and an increase in the height of the time ball tower. This increased height caused some dismay for Scott as it blocked out an increased area of the eastern sky. The completed building combined, for the first time in a major Sydney building, two architectural streams - Italian High Renaissance Palazzo and the Italian Villa forms. These contributed the symmetry of the townhouse facade for the residence and an asymmetry for the observatory born of the peculiar needs of transit room, equatorial dome and time ball tower. The building was thus elevated from basic necessity to fashionable stylishness. Dawson's budget had enabled him to emphasise the distinction between the private and the public, the domestic and the official. The style and form was overlaid with early Victorian theories of fitness and association, that style should be chosen to indicate the nature and status of the building and in some cases, the site. Operations, 1858 to 1980s Scott occupied the residence in 1858 and commenced a trial operation of the time ball in June. His initial equipment was modest, mostly the instruments from Parramatta. He did, however, obtain the money for an equatorial telescope. In 1862 Scott resigned, recommending prominent amateur astronomer John Tebbutt as his replacement. Tebbutt declined the offer and the search for a replacement was commenced. In the meantime, his assistant Henry Chamberlain Russell was left in charge of the observatory. In January 1864 the new appointee George Robarts Smalley arrived and Russell was his second in command. In 1870 Smalley died and was replaced by Russell. Russell's talent, entrepreneurial flair, intimate knowledge of how to work the political and bureaucratic system of NSW and longevity gave him a 35-year tenure as Government Astronomer and made him the Grand Old Man of physical science in the colonies. It was during Russell's period that Sydney Observatory was popularly believed to have been at its professional zenith, particularly from the 1870s through to the 1890s. Russell wasted no time in pressing the government for the necessary physical and instrumental resources to carry out his astronomical programs at the observatory. The addition of a west wing designed by colonial architect James Barnett was the main work resulting from this. It provided for a major ground floor room for Russell, a library, a second equatorial dome on a tower at its northern extremity which removed the blind spot imposed by the time ball tower. An enlarged Muntz metal dome was also placed on the old equatorial tower to accommodate a new Schroeder telescope. The telescope remains a prized and functional possession today. Russell also turned his attention to improving the residence, claiming it was not large enough to accommodate his family. In 1875 Russell succeeded in securing an extension of the observatory enclosure. Like his predecessors, he had been concerned with the restrictive nature of the observatory grounds which made siting of meteorological and auxiliary astronomical instruments difficult, if not impossible. This extension, together with the adjacent signal station give the site its present symmetrical perimeter. The Astrographic Catalogue was Russell's greatest commitment and would affect programs at the observatory for 80 years. His interest in the application of photography to astronomy and a visit to Paris in 1887 prompted Russell to take part in a "great star catalogue". The Sydney Zone of the catalogue was a massive logistical enterprise and was not practically completed until 1964. Russell died in 1907 after taking leave for an extended period of time due to ill health. His assistant Alfred Lenehan was appointed acting Government Astronomer during this period and later Government Astronomer in 1907. However, in 1906 a premier's conference resolved that the Commonwealth Government would take over meteorological work, leaving astronomy to the states. Thus, the meteorological section of the observatory became a Commonwealth agency under the direction of a former officer of the observatory, Henry Hunt. Lenehan and Hunt continuously quarrelled and did not develop a good working relationship. In January 1908 Lenehan had a stroke and never returned to work. At the same time the Commonwealth agency was installed in the observatory residence. William Edward Raymond, the officer responsible for transit work, became officer in charge for four years, until the appointment of William Ernest Cooke in 1912. Cooke was lured to Sydney from Perth Observatory with promises of a new site located in Wahroongah, then free of city lights and traffic, the purchase of modern instruments and a world trip to investigate the latest developments. None of these eventuated during Cooke's fourteen years at the observatory. In 1916 the board of visitors to the observatory was reconstituted. Russell had allowed it to lapse during his term of office and in 1917 the residence was again inhabited by the Astronomer. All government astronomers from Scott to Cooke were worried about increasing levels of city light, vibration from traffic and magnetic disturbance which rendered the Flagstaff Hill site increasingly unsuitable. Recommendations had been made by Smalley in 1864 and others in the first quarter of the twentieth century. While Russell had managed to have the astrographic telescope relocated to Pennant Hills, there was general worry over the reaction to the cost of relocation of the whole observatory. In July 1925 Cooke wrote to his minister pointing out the problems at the site and with the equipment. The State Cabinet took him at his word and in October decided to close the observatory rather than face the cost of removal and re-equipment. However, protests from the Board of Visitors, the Royal Society of NSW, the NSW Branch of the British Astronomical Association, the University of Sydney and interested members of the public caused the Government to change its mind and allow the observatory to continue - but with a heavily reduced staff and program. Most of the staff were transferred to other departments and Cooke was retired the following year. Only the time ball and completion of the astrographic program survived. This experience inhibited later Government Astronomers in their arguments for a new site. Two World Wars, a great depression and a commitment to a logistically exacting astrographic program helped reduce the vitality of the establishment in the twentieth century. The deployment of major resources to the astrographic program became something of an incubus as the twentieth century progressed. The Government Astronomers could not suspend or abort the program even if they had thought it desirable. At the same time the fulfilment of international obligations under the program was largely instrumental in the survival of the observatory. The completion of the program in 1964 and publication of the final volume in 1971 meant the observatory's days were numbered. Other fundamental reasons also contributed to the notion that the observatory was no longer a viable proposition. The transfer of meteorology to the Commonwealth in 1908 removed the observatory's most high-profile public service, electric telegraphy and radio had reduced and in time eliminated the need for local navigational and time services. Ambient city light was starting to restrict astronomical observation though the place was still suitable for the time-consuming analysis of the observations and other astronomical work together with functions such as a public observatory and a centre for public and media enquiries. Post World War II was an exciting time for Australian astronomical development, particularly in radio astronomy. These developments bypassed Sydney though the Government Astronomer Harley Wood kept a close involvement as the first president of the Astronomical Society of Australia (ASA) in 1966 and as the co-ordinator of the first International Astronomical Union (IAU) General Assembly to be held in the southern hemisphere in Sydney, 1973. Without major capital funds to develop its own specialisations in the west, Sydney remained tied to its traditional role. Despite this there was some positive activity at the observatory. During the 1950s and 1960s under Wood, the observatory enjoyed a modest renaissance. Staff numbers were built up and new equipment acquired. Both the Sydney and Melbourne sections of the Astrographic catalogue were completed and published. A new domed building was constructed in the south-east corner of the observatory to house the Melbourne star camera that replaced the original Sydney one. A new survey of the southern sky was commenced and by 1982 Wood's successor William Robertson had completed the photography and measurement was underway. Education was another aspect of the observatory's work that Wood developed. Always one of its aims, increasing numbers of visitors, including teaching students, attended the observatory. These activities commanded respect for Sydney Observatory in astronomical circles, but its image in the NSW Parliament and associated Public Service remained forgettable. Wood's annual reports failed to help this. They did not communicate any sense of excitement and worth in the observatory. Disestablishment as a functioning observatory The disestablishment of the observatory echoed that of fifty years earlier when Cooke stressed the need for a new location. The Chairman of the Board of Visitors wrote a letter to the Premier in 1979 urging the establishment of a remote observing site for the observatory and stressing the difficulty of the conditions at the existing site. This coincided with a nationwide review of astronomy facilities commissioned by the ASA and led by Monash University Professor of Astronomy Kevin Westfold (1980) This concluded that astronomy was a federal responsibility and that resources should be allocated to research operations, highlighting radio astronomy. The financial difficulties of the State of NSW at that time resulted in a letter from the Premier in June 1982 announcing his decision to transfer the observatory to the Museum of Applied Arts and Sciences and discontinue scientific work. Despite letters from international astronomers, and a concerted effort from now-retired Harley Wood, the Government did not rescind its decision. In July 1984 the Minister for Public Works, Ports and Roads announced an $800,000 project to restore Sydney Observatory for astronomy education, public observatory and a Museum of Astronomy. While the importance of the exterior was recognised, the interior was less fortunate. Work inside the building in the creation of the museum involved the staged removal of almost all instruments, equipment, and furniture and furnishings to the Museum's store. The astrographic building was demolished and the dome, instruments and most of the glass plate and paper collection was removed to Macquarie University for future research use. In 1997 the observatory was refurbished, this time instruments were returned to their original locations or showcased. 'The "By the light of the Southern Stars" exhibition theme also included the Parramatta Observatory instruments and Indigenous Astronomy. In 1999 a major stonemasonry repair project on the observatory building commenced. This continued through to 2008. In 2002 the conservation plan was updated by Kerr, this time complimentary on the relocation and interpretation of the instruments. A number of key astronomical events have occurred in recent years, most notable are Halleys Comet (1986), The impact of Shoemaker Levy on Jupiter (1994), Mars at its closest encounter (2003), transits of Venus (2004, 2012), Comet McNaught (2007), planetary alignments and eclipses. Thousands of people came to the observatory to view these through telescopes and to see relevant exhibitions. Further the observatory provided information about these events to many more people either directly or through the media. In 2008, for the 150th anniversary, the Signal Station building was stabilised, one of the original two flagstaffs re-constructed and an archaeological investigation commenced around the base of the fort led by NSW Government Architects, building design and Heritage office and Casey and Lowe. Original fort footings were uncovered and the base of a room which was once a bombproof inside the fort wall foundations. In 2009 permission was granted for a temporary marquee to be erected for a restricted period of time in order to raise funds. Furthermore, the Astrographic dome and instruments have been returned by Macquarie University to the Museum store where they are awaiting conservation and a Heritage NSW approved structure on the observatory site. The most significant change to Sydney Observatory in 50 years, the new Eastern Dome was opened on 27 January 2015, by the Deputy Premier Troy Grant and Minister for Disability Services, John Ajaka. Georg Merz and Sons, vintage 7.25-inch refracting telescope Located at the Sydney Observatory is a vintage 7.25-inch refracting telescope on an Equatorial mount that was manufactured by the German company Georg Merz and Sons between 1860 and 1861. The 7.25-inch Merz refracting telescope arrived at Sydney Observatory, Sydney, Australia, in 1861. Description The observatory is a sandstone two-storey building in the Italianate style. There are two telescope domes on octagonal bases and a four-storey tower for the time-ball. The 1858 building designed by the Colonial Architect, Alexander Dawson, comprised a dome to house the equatorial telescope, a room with long, narrow windows for the transit telescope, an office for calculations, and a residence for the astronomer. A western wing was added in 1877 with office and library space and a second dome for another telescope. Some of the first astronomical photographs of the southern sky were taken at the observatory, under the direction of Henry Chamberlain Russell. The observatory also took part in the compilation of the first atlas of the whole sky, The astrographic catalogue. The part completed at Sydney took over 70 years, from 1899 to 1971, and filled 53 volumes. The observatory once contained offices, instruments, a library and an astronomer's residence. It is now a public observatory and a museum of astronomy and meteorology. The building is of Florentine Renaissance style and the storeys are divided by string courses while articulated quoins at corners, stone bracketed eaves and entablatures to openings of the residence contribute to the fine stone masonry work. A single storey wing to the north has had a timber balcony verandah with a stone balustrade built above. Windows are of twelve pane type and the doors are six panels. The physical condition is good. Modifications and dates 1796First windmill built on hill. 1796–97to crush grain - abandoned 1806. 1800At least two six-pounder cannons located on hill. 1804Commencement of construction of Fort Phillip as protection versus convict uprising. Site known as Citadel Hill. Building work continued until 1806, then abandoned, with the fort unfinished. 1808Flagstaffs erected on eastern side of Fort Phillip parapet. 1823Semaphore and flagstaff added to hill. 1838Dual purpose staff and telegraph masters hut noted on site. 1847Signal Station built – finished 1848. 1857Signal Station altered, and in 1859, took its present form by 1864. 1858Demolition of windmill tower and construction of Observatory - finished 1859. 1876–78West wing built. Other alterations to residence in 1907. Most of the residence lath and plaster ceilings replaced by decorative pressed metal ceilings and matching cornices. 1907New staircase constructed in residence. 20th centuryMost observatory ceilings replaced by asbestos cement sheeting. - Addition of picture rails. 1982Wran Government decision to cease scientific work on site, Powerhouse Museum takes responsibility for management 1984–87DPWS manage major works to provide a museum of astronomy, exhibitions etc. November 1987Signal Station use as by Museum agreed to by Minister for Public Works. 1980sObservatory ceilings replaced with plaster-board; some floors replaced with particle board sheeting; some basement floors quarry tiled. 1985New staircase constructed in south west tower. 1987Garden re-landscaping/reinstatement to conform with Russell's plan of 1893, replanting with appropriate 19th century species (oleander, agaves, plumbago) by Royal Botanic Gardens Sydney staff. 1993Signal Station Messengers Cottage vacated and use as museum agreed in-principle by Treasurer in 11/1993. 1995Signal Station Messengers Cottage refurbished for use as offices by museum staff. All walls were plastered but have been progressively repaired and replaced over the years. 1997Many original instruments were conserved and restored to their former locations. 2008The Signal Station was restored and a replica flagstaff re-instated on the South rampart of the Fort wall for the Sydney Observatory 150th celebration. 2015Opened the East Dome which caters for people with disability. This won the National Trust's 2015 Heritage Award for Adaptive Reuse. Heritage listing As at 20 October 2005, the observatory is of exceptional significance in terms of European culture. Its dominant location beside and above the port town and, later, City of Sydney made it the site for a range of changing uses, all of which were important to, and reflected, stages in the development of the colony. These uses included: milling (the first windmill); defence (the first, and still extant, fort fabric); communications (the flagstaffs, first semaphore and first electric telegraph connection); astronomy, meteorology and time keeping. The surviving structures, both above and below ground, are themselves physical documentary evidence of 195 years' changes of use, technical development and ways of living. As such they are a continuing resource for investigation and public interpretation. The place has an association with an extensive array of historical figures most of whom have helped shape its fabric. These include: colonial Governors Hunter, Bligh, Macquarie & Denison; military officers and engineers Macarthur; Barrallier; Bellasis and Minchin; convicts: the as yet unnamed constructors of the mill and fort; architects: Greenway (also a convict), Lewis, Blacket, Weaver, Dawson and Barnet; signallers and telegraphists such as Jones and the family Moffitt; astronomers: particularly PP King, Scott, Smalley, Russell, Cooke and Wood. The elevation of the site, with its harbour and city views and vistas framed by mature Moreton Bay fig (Ficus macrophylla) trees of the surrounding park, make it one of the most pleasant and spectacular locations in Sydney. The picturesque Italianate character and stylistic interest of the observatory and residence building, together with the high level of competence of the masonry (brick and stone) of all major structures on the site, combine to create a precinct of unusual quality; Finally, the continued use of the observatory for astronomical observations and the survival of astronomical instruments, equipment (Appendix 4) and some early furniture (Appendix 3), although temporarily dispersed, and the retention of most interior spaces, joinery, plasterwork, fireplaces, and supports ensure that the observatory can remain the most intact and longest serving early scientific building in the State. Also of significance for relationship of Commonwealth and State powers. Site of the first intercolonial conference on meteorology and astronomy. An excellent example of a Colonial building erected for scientific purposes and continuing to perform its function at the present time. The structure makes an imposing composition atop the historic hill originally known as Flagstaff Hill and occupies the historic Fort Phillip site (1804–45). Designed by the colonial architect Alexander Dawson and built in 1858. Sydney Observatory was listed on the New South Wales State Heritage Register on 22 December 2000 having satisfied the following criteria. The place is important in demonstrating the course, or pattern, of cultural or natural history in New South Wales. The observatory's dominant location beside and above the port town, and later, city of Sydney, made it the site for a range of changing uses. All of these were important to, and reflected changes in the development of the colony. The place has an association with an extensive array of historical figures, most of whom have helped shape its fabric. These include colonial governors, military officers and engineers, convicts, architects and astronomers. The place is important in demonstrating aesthetic characteristics and/or a high degree of creative or technical achievement in New South Wales. The elevation of the site with its harbour and city views and vistas framed by the mature fig trees of the surrounding park, make it one of the most pleasant and spectacular locations. The picturesque Italianate character and stylistic interest of the observatory and residence building, together with the high level of competence of the masonry (both stone and brick) of all major structures on the site, combine to create a precinct of unusual quality. The place has potential to yield information that will contribute to an understanding of the cultural or natural history of New South Wales. The surviving structures, both above and below ground, are themselves physical documentary evidence of 195 years of changes of use, technical development and ways of living. As such they are a continuing resource for investigation and public interpretation. See also Australian non-residential architectural styles List of astronomical observatories References Bibliography Attribution External links Sydney Observatory [CC-By-SA] Further Links and Images duchs.com Astronomical observatories in New South Wales Buildings and structures in Sydney Museums in Sydney Meteorological observatories Science museums in Australia 1858 establishments in Australia New South Wales State Heritage Register sites located in Millers Point Victorian architecture in Sydney Military installations in New South Wales Windmills in Australia Time guns Event venues in New South Wales Signal flags Lighthouses in New South Wales Articles incorporating text from the New South Wales State Heritage Register

3914744

https://en.wikipedia.org/wiki/Cold%20Food%20Festival

Cold Food Festival

The Cold Food or Hanshi Festival is a traditional Chinese holiday which developed from the local commemoration of the death of the Jin nobleman Jie Zitui in the 7thcenturyBC under the Zhou dynasty, into an occasion across East Asia for the commemoration and veneration of ancestors by the 7th-century Tang dynasty. Its name derives from the tradition of avoiding the lighting of any kind of fire, even for the preparation of food. This practice originally occurred at midwinter for as long as a month, but the hardship this involved led to repeated attempts to ban its observance out of concern for its practitioners. By the end of the Three Kingdoms Period (3rd century), it was limited to three days in the spring around the Qingming solar term. Under the Tang, ancestral observance was limited to the single day which is now the Tomb-Sweeping Festival. The Tomb-Sweeping Festival is an official holiday in several countries, and the Cold Food Festival which stretches either side of it continues to see some observance in China, South Korea, and Vietnam. Legend The usual story for the origin of the Cold Food and Tomb-Sweeping Festivals concerns the 7th-century-BC Jin nobleman Jie Zhitui, a model of self-sacrificing loyalty. During the Spring and Autumn Period of Chinese history, the Zhou Kingdom began to break up into its constituent parts and their lords gained more and more freedom from central control. One of these states was Jin, around modern Shanxi. As was common among wealthy Chinese at the time, its duke had many wives. One of them, Li Ji, was of lower status and came from the Rong tribes who lived to China's west, but successfully schemed to become a full wife and to establish her son as the duke's successor. Her older stepson Ji Chong'er was framed for revolting against the duke in 655BC, forcing the prince to flee for his life to his mother's family among the Di tribes north of China. Only 15 of his men followed him into exile. These included Jie Zhitui, who entertained the prince with his poems and music. He was so considerate of his lord that once, when their supplies were stolen while traveling through Wey, he used meat from his own thigh to make soup to relieve the prince's hunger. In 636BC, the duke of Qin finally invaded Jin on Chong'er's behalf and installed him as its duke. (Posthumously, he became known as the "Wen" or "Civilized Duke" of Jin.) In 635BC, the new duke was generous to those who had helped him in adversity but overlooked Jie, who sadly withdrew into poor obscurity in the forests near . The duke sent repeated envoys to lure Jie back to court, but he felt no ambition for political power. Too loyal to directly criticize his master but too principled to accept a place in a corrupt administration, he opted to simply remain in seclusion. Annoyed, the duke ordered a forest fire to be started around three sides of the mountain to smoke Jie and his mother out of hiding. Instead of coming out, they were burnt alive. Jie's charred corpse was found still standing, embracing or tightly bound to a tree. In his remorse, the duke renamed the mountain Mt.Jie, established the town still known as Jiexiu ("Jie's Rest"), and inaugurated the Cold Food Festival as a memorial period for Jie. In addition to the festival, the story also occasioned the Chinese proverb that, "while some can burn off an entire mountain, others are kept from even lighting up to eat their rice". History The first part of this legend appears to be historical. In the earliest accounts, however, Jie is more prideful than sad and is not killed in a fire. The 4th-century-BC commentary on Confucius's Spring and Autumn Annals traditionally credited to Zuo Qiuming includes a Thucydidean passage where Jie argues with his mother about their future. Jie credits Heaven with having restored Chong'er to his rightful place and is disgusted by the credit-seeking and job-hunting behavior of his fellows, whom he considers worse than thieves. He also finds his lord unworthy for failing to reward him despite his failure to present himself at court. His mother asks him to at least go before the duke, but Jie admits his bitter criticism of the other lords makes that impossibly embarrassing. His mother accepts his decision to withdraw to a hermitage and goes with him. Ji Chong'er belatedly remembers his obligations to Jie and looks for him. When this proves vain, he accepts the situation and sets aside the produce of the fields of "Mëenshang" to endow sacrifices in Jie's honor, "a memento... of my neglect and a mark of distinction for the good man". Other sources from the Zhou and early Han mention and praise Jie for various reasons. The poems of the Songs of Chu extol him for his loyalty and proper treatment of his lord's forgetfulness. The Spring and Autumn Annals compiled under Lü Buwei praises his altruism and lack of personal ambition. At some point before the composition of the Han-era Biographies of the Immortals, Jie came to be revered as a Taoist immortal. The Cold Food Festival is first mentioned in Huan Tan's New Discussions, composed around the beginning of the 1st century. It records that the commoners of Taiyuan Commandery avoided using fire in preparing their food for five days around midwinter, upholding this taboo even when they are gravely ill. This was done in Jie Zhitui's honor. A biography in the Book of the Later Han relates how the magistrate for Bingzhou (i.e., Taiyuan) found people rich and poor observing a "dragon taboo" against lighting a fire during the month of Jie's death in midwinter, lest they anger his spirit. Many of the old and young died every year because of the hardship this brought. The magistrate Zhou Ju wrote an oration around AD130 praising Jie but admonishing the people for a tradition that harmed so many that it could not have been what the sage intended. He then had the oration displayed at Jie's temple and distributed among the poor. This did not end the Cold Food Festival, but the biography notes that local superstitions did improve "to a certain extent". The improvement is not explained but, at some point over the next century, it moved from the middle of winter to late spring, 105 days after the dongzhi solar term. Since it also spread from Taiyuan to the surrounding commanderies of Shangdang, Xihe, and Yanmen and was still causing some hardship, Cao Cao attempted to outlaw the Cold Food Festival in AD206. The heads of offending families were liable for 6 months' hard labor, their local official was liable for one month himself, and their magistrate was to lose one month's salary. Cao Cao's effort was a failure, with observance of the Cold Food Festival on Qingming and for up to a month around it being reported by the mid-3rd century. Shi Le, the Jie emperor of the Later Zhao in the early 4th century, again tried to forbid it. The next year a massive hailstorm devastated crops and forests throughout Shanxi. On the advice of his ministers, he again approved the festival in the region around Taiyuan. The Northern Wei similarly banned the festival in 478 and 496, but were also compelled to approve its observance around . These prohibitions failed to such an extent that, by the time of Jia Sixie's Qimin Yaoshu, a day-long Cold Food Festival had spread across most of China, moved to the day before the Qingming solar term. The Cold Food Festival grew to a three-day period and began to incorporate ancestral veneration under the Tang and remained more important than celebrations of the Qingming solar term as late as the Song. The present Tomb-Sweeping Festival on Qingming grew by incorporating the Cold Food observances along with the separate holiday of Shangsi. The Cold Food Festival had almost completely disappeared by the end of the Qing. Controversy Since the early 7th century, Chinese and Western scholars have argued for alternative origins for the festival. Du Gongzhan, the editor of the late-Sui Record of the Seasons of Jingchu, connected it with a ritual avoidance of fire mentioned in the Rites of Zhou: "In mid-spring, they announce the prohibition of fire in the capital using a bell with a wooden clapper". This prohibition was related to the ancient Chinese use of different kinds of firewood according to the seasons, particularly after the development of Chinese astrology that considered the heliacal rising of Antares to be an occasion for great risk of conflagration and wildfire. Du was followed in his conjecture by others, including Li Fu. The Sinologist J.J.M. de Groot argued for its origin as a celebration of the sun's "victory" at the vernal equinox, based on a comparative anthropological analysis drawing on Ovid, Macrobius, Lucian, and Epiphanius of Salamis. James Frazer and his followers similarly considered it either a "sun-charm" or "purification" from its similarities to other "fire-festivals". Claude Lévi-Strauss based his analysis of the festival as a kind of Chinese Lent upon a mistranslation of the relevant passage in the Rites of Zhou by Frazer. Eberhard connected it with his idea of a prehistoric spring-based calendar and made the Cold Food Festival a remnant of its original New Year. The unanimous connection of the festival to Jie Zhitui in the early sources and the dependence of these later theories on the Cold Food Festival's occurrence in late spring—when it in fact began as a mid-winter observance—suggests that none of them are likely accurate. One contemporary record of ritual fire-avoidance coming from a separate source in southeastern China concerned the late-2nd-centuryBC "kings" of "Yue" Mi (, Yuè Míwáng) and Yao (, Yuè Wáng Yáo, and , Yuè Yáowáng). These were actually princes of the old Yue royal family fighting over the southern successor state of Minyue. Supposedly, the Mi King was beheaded during a battle with Yao but his body continued to stay atop his horse all the way back to "Wu Village", where he was buried. As late as the 10th century, residents of the area avoided fire on the day of his death as a mark of respect to his spirit. This southern equivalent to the Cold Food Festival was not celebrated annually, though, but on every "wu day" of the old Chinese calendar, a generally unlucky day to some Taoists. Observance China The Cold Food Festival was originally observed at mid-winter (the Dongzhi solar term), but moved to late spring (the Qingming solar term) around the 2nd century. Its primary activity was a strict taboo against using fire, usually under the superstitious belief that violations led to violent weather. Leading up to the 6th century, there was a patch of blackened trees on that were used for local worship of Jie Zhitui and had a reputation for miracles. Traditional cold foods included lǐlào , a kind of congee flavored with apricot pits and malt sugar. Later activities included visiting ancestral tombs, cock fighting, playing on swings, beating blankets, and tug-of-war games. The Cold Food Festival is generally ignored in modern China, except to the extent that it has influenced some of the activities and traditional foods for the Tomb-Sweeping Festival. In the city of Jiexiu in Shanxi Province, near where Jie died, locals still commemorate the festival, but even there the tradition of eating cold food is no longer practiced. South Korea The Korean equivalent Hansik (Hangul: 한식), takes place on the 105th day after dongzhi, which translates to April 5 in the Gregorian calendar, except in leap years when it is on April 4 instead. It is a day to welcome the warm weather thawing the frozen lands. On this day, rites to worship ancestors are observed early in the morning, and the family visits their ancestors' tombs to tidy up. The custom of eating cold food on the day has, however, disappeared. Since this day coincides with Arbor Day, public cemeteries are crowded with visitors planting trees around the tombs of their ancestors. Vietnam The Vietnamese equivalent Tết Hàn Thực is celebrated in most parts of the country on the 3rd day of the 3rd lunar month, but only marginally. People cook glutinous rice balls called bánh trôi but the holiday's origins are largely forgotten, and the fire taboo is also largely ignored. See also Tết Hàn Thực List of festivals in Asia Traditional and Public holidays in China, Hong Kong, and Macao and on Taiwan Festivals and Public holidays in South Korea and North Korea List of Korean traditional festivals Notes References Citations Bibliography . . . . . . . . . . . . . . . . Festivals in China Festivals in Korea Food and drink festivals in South Korea April observances Observances set by the Chinese calendar Observances set by the Korean calendar Spring (season) events in China Winter solstice

3918713

https://en.wikipedia.org/wiki/Castle-guard

Castle-guard

Castle-guard was an arrangement under the feudal system, by which the duty of finding knights to guard royal castles was imposed on certain manors, knight's fees or baronies. The greater barons provided for the guard of their castles by exacting a similar duty from their sub-enfeoffed knights. The obligation was commuted very early for a fixed money payment, a form of scutage known as "castle-guard rent", which lasted into modern times. Castle-guard was a common form of feudal tenure, almost ubiquitous, on the Isle of Wight where all manors were held from the Lord of the Isle of Wight, seated at Carisbrook Castle. References Castles Feudalism Land tenure

3925437

https://en.wikipedia.org/wiki/74P/Smirnova%E2%80%93Chernykh

74P/Smirnova–Chernykh

74P/Smirnova–Chernykh is a periodic comet in the Solar System. It fits the definition of an Encke-type comet with (TJupiter > 3; a < aJupiter), and is a Quasi-Hilda comet. It was discovered in late March 1975 by Tamara Mikhajlovna Smirnova while examining exposures from the Crimean Astrophysical Observatory. In the discovery images the comet had an apparent magnitude of ~15. In the year of discovery, the comet came to perihelion on August 6, 1975. The comet had been photographed during 1967, but was identified as an asteroid and assigned the designation 1967 EU. The comet is estimated at about 4.46 km in diameter, and currently has an orbit contained completely inside of the orbit of Jupiter. References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 74P at Kazuo Kinoshita's Comets Images of 74P/Smirnova–Chernykh from the 2009 passage Periodic comets Encke-type comets 0074 Comets in 2018 19750304

3925517

https://en.wikipedia.org/wiki/77P/Longmore

77P/Longmore

77P/Longmore is a periodic comet in the Solar System, with a period of 6.8 years. It was discovered by Andrew Jonathan Longmore on a photographic plate taken on 10 June 1975 at the 1.22m Schmidt telescope at Siding Spring Observatory, New South Wales, Australia. Its brightness was estimated at an apparent magnitude of 17. After further observations Brian G. Marsden was able to calculate the perihelion date at 4 November 1975 and the orbital period as 6.98 years. The next perihelion date was computed to be 21 October 1981. T. Seki of Geisei, Japan relocated the comet on 2 January 1981 with a brightness of magnitude 18. It has since been observed in 1988, 1995, 2002 and 2009. On 17 October 1963 the comet had passed from Jupiter. During the 2023 perihelion passage the comet brightened to about apparent magnitude 14–15. See also List of numbered comets References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 77P at Kronk's Cometography Periodic comets 0077 Comets in 2016 19750610

3928494

https://en.wikipedia.org/wiki/Hyperspectral%20imaging

Hyperspectral imaging

Hyperspectral imaging collects and processes information from across the electromagnetic spectrum. The goal of hyperspectral imaging is to obtain the spectrum for each pixel in the image of a scene, with the purpose of finding objects, identifying materials, or detecting processes. There are three general types of spectral imagers. There are push broom scanners and the related whisk broom scanners (spatial scanning), which read images over time, band sequential scanners (spectral scanning), which acquire images of an area at different wavelengths, and snapshot hyperspectral imagers, which uses a staring array to generate an image in an instant. Whereas the human eye sees color of visible light in mostly three bands (long wavelengths - perceived as red, medium wavelengths - perceived as green, and short wavelengths - perceived as blue), spectral imaging divides the spectrum into many more bands. This technique of dividing images into bands can be extended beyond the visible. In hyperspectral imaging, the recorded spectra have fine wavelength resolution and cover a wide range of wavelengths. Hyperspectral imaging measures continuous spectral bands, as opposed to multiband imaging which measures spaced spectral bands. Engineers build hyperspectral sensors and processing systems for applications in astronomy, agriculture, molecular biology, biomedical imaging, geosciences, physics, and surveillance. Hyperspectral sensors look at objects using a vast portion of the electromagnetic spectrum. Certain objects leave unique 'fingerprints' in the electromagnetic spectrum. Known as spectral signatures, these 'fingerprints' enable identification of the materials that make up a scanned object. For example, a spectral signature for oil helps geologists find new oil fields. Sensors Figuratively speaking, hyperspectral sensors collect information as a set of 'images'. Each image represents a narrow wavelength range of the electromagnetic spectrum, also known as a spectral band. These 'images' are combined to form a three-dimensional (x,y,λ) hyperspectral data cube for processing and analysis, where x and y represent two spatial dimensions of the scene, and λ represents the spectral dimension (comprising a range of wavelengths). Technically speaking, there are four ways for sensors to sample the hyperspectral cube: Spatial scanning, spectral scanning, snapshot imaging, and spatio-spectral scanning. Hyperspectral cubes are generated from airborne sensors like NASA's Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), or from satellites like NASA's EO-1 with its hyperspectral instrument Hyperion. However, for many development and validation studies, handheld sensors are used. The precision of these sensors is typically measured in spectral resolution, which is the width of each band of the spectrum that is captured. If the scanner detects a large number of fairly narrow frequency bands, it is possible to identify objects even if they are only captured in a handful of pixels. However, spatial resolution is a factor in addition to spectral resolution. If the pixels are too large, then multiple objects are captured in the same pixel and become difficult to identify. If the pixels are too small, then the intensity captured by each sensor cell is low, and the decreased signal-to-noise ratio reduces the reliability of measured features. The acquisition and processing of hyperspectral images is also referred to as imaging spectroscopy or, with reference to the hyperspectral cube, as 3D spectroscopy. Scanning techniques There are four basic techniques for acquiring the three-dimensional (x, y, λ) dataset of a hyperspectral cube. The choice of technique depends on the specific application, seeing that each technique has context-dependent advantages and disadvantages. Spatial scanning In spatial scanning, each two-dimensional (2-D) sensor output represents a full slit spectrum (x, λ). Hyperspectral imaging (HSI) devices for spatial scanning obtain slit spectra by projecting a strip of the scene onto a slit and dispersing the slit image with a prism or a grating. These systems have the drawback of having the image analyzed per lines (with a push broom scanner) and also having some mechanical parts integrated into the optical train. With these line-scan cameras, the spatial dimension is collected through platform movement or scanning. This requires stabilized mounts or accurate pointing information to 'reconstruct' the image. Nonetheless, line-scan systems are particularly common in remote sensing, where it is sensible to use mobile platforms. Line-scan systems are also used to scan materials moving by on a conveyor belt. A special case of line scanning is point scanning (with a whisk broom scanner), where a point-like aperture is used instead of a slit, and the sensor is essentially one-dimensional instead of 2-D. Spectral scanning In spectral scanning, each 2-D sensor output represents a monochromatic ('single-colored'), spatial (x, y) map of the scene. HSI devices for spectral scanning are typically based on optical band-pass filters (either tunable or fixed). The scene is spectrally scanned by exchanging one filter after another while the platform remains stationary. In such 'staring', wavelength scanning systems, spectral smearing can occur if there is movement within the scene, invalidating spectral correlation/detection. Nonetheless, there is the advantage of being able to pick and choose spectral bands, and having a direct representation of the two spatial dimensions of the scene. If the imaging system is used on a moving platform, such as an airplane, acquired images at different wavelengths corresponds to different areas of the scene. The spatial features on each of the images may be used to realign the pixels. Non-scanning In non-scanning, a single 2-D sensor output contains all spatial (x, y) and spectral (λ) data. HSI devices for non-scanning yield the full datacube at once, without any scanning. Figuratively speaking, a single snapshot represents a perspective projection of the datacube, from which its three-dimensional structure can be reconstructed. The most prominent benefits of these snapshot hyperspectral imaging systems are the snapshot advantage (higher light throughput) and shorter acquisition time. A number of systems have been designed, including computed tomographic imaging spectrometry (CTIS), fiber-reformatting imaging spectrometry (FRIS), integral field spectroscopy with lenslet arrays (IFS-L), multi-aperture integral field spectrometer (Hyperpixel Array), integral field spectroscopy with image slicing mirrors (IFS-S), image-replicating imaging spectrometry (IRIS), filter stack spectral decomposition (FSSD), coded aperture snapshot spectral imaging (CASSI), image mapping spectrometry (IMS), and multispectral Sagnac interferometry (MSI). However, computational effort and manufacturing costs are high. In an effort to reduce the computational demands and potentially the high cost of non-scanning hyperspectral instrumentation, prototype devices based on Multivariate Optical Computing have been demonstrated. These devices have been based on the Multivariate Optical Element spectral calculation engine or the Spatial Light Modulator spectral calculation engine. In these platforms, chemical information is calculated in the optical domain prior to imaging such that the chemical image relies on conventional camera systems with no further computing. As a disadvantage of these systems, no spectral information is ever acquired, i.e. only the chemical information, such that post processing or reanalysis is not possible. Spatiospectral scanning In spatiospectral scanning, each 2-D sensor output represents a wavelength-coded ('rainbow-colored', λ = λ(y)), spatial (x, y) map of the scene. A prototype for this technique, introduced in 2014, consists of a camera at some non-zero distance behind a basic slit spectroscope (slit + dispersive element). Advanced spatiospectral scanning systems can be obtained by placing a dispersive element before a spatial scanning system. Scanning can be achieved by moving the whole system relative to the scene, by moving the camera alone, or by moving the slit alone. Spatiospectral scanning unites some advantages of spatial and spectral scanning, thereby alleviating some of their disadvantages. Distinguishing hyperspectral from multispectral imaging Hyperspectral imaging is part of a class of techniques commonly referred to as spectral imaging or spectral analysis. The term “hyperspectral imaging” derives from the development of NASA's Airborne Imaging Spectrometer (AIS) and AVIRIS in the mid-1980s. Although NASA prefers the earlier term “imaging spectroscopy” over “hyperspectral imaging,” use of the latter term has become more prevalent in scientific and non-scientific language. In a peer reviewed letter, experts recommend using the terms “imaging spectroscopy” or “spectral imaging” and avoiding exaggerated prefixes such as “hyper-,” “super-” and "ultra-,” to prevent misnomers in discussion. Hyperspectral imaging is related to multispectral imaging. The distinction between hyper- and multi-band is sometimes based incorrectly on an arbitrary "number of bands" or on the type of measurement. Hyperspectral imaging (HSI) uses continuous and contiguous ranges of wavelengths (e.g. 400 - 1100 nm in steps of 1 nm) whilst multiband imaging (MSI) uses a subset of targeted wavelengths at chosen locations (e.g. 400 - 1100 nm in steps of 20 nm). Multiband imaging deals with several images at discrete and somewhat narrow bands. Being "discrete and somewhat narrow" is what distinguishes multispectral imaging in the visible wavelength from color photography. A multispectral sensor may have many bands covering the spectrum from the visible to the longwave infrared. Multispectral images do not produce the "spectrum" of an object. Landsat is an excellent example of multispectral imaging. Hyperspectral deals with imaging narrow spectral bands over a continuous spectral range, producing the spectra of all pixels in the scene. A sensor with only 20 bands can also be hyperspectral when it covers the range from 500 to 700 nm with 20 bands each 10 nm wide. (While a sensor with 20 discrete bands covering the visible, near, short wave, medium wave and long wave infrared would be considered multispectral.) Ultraspectral could be reserved for interferometer type imaging sensors with a very fine spectral resolution. These sensors often have (but not necessarily) a low spatial resolution of several pixels only, a restriction imposed by the high data rate. Applications Hyperspectral remote sensing is used in a wide array of applications. Although originally developed for mining and geology (the ability of hyperspectral imaging to identify various minerals makes it ideal for the mining and oil industries, where it can be used to look for ore and oil), it has now spread into fields as widespread as ecology and surveillance, as well as historical manuscript research, such as the imaging of the Archimedes Palimpsest. This technology is continually becoming more available to the public. Organizations such as NASA and the USGS have catalogues of various minerals and their spectral signatures, and have posted them online to make them readily available for researchers. On a smaller scale, NIR hyperspectral imaging can be used to rapidly monitor the application of pesticides to individual seeds for quality control of the optimum dose and homogeneous coverage. Agriculture Although the cost of acquiring hyperspectral images is typically high, for specific crops and in specific climates, hyperspectral remote sensing use is increasing for monitoring the development and health of crops. In Australia, work is under way to use imaging spectrometers to detect grape variety and develop an early warning system for disease outbreaks. Furthermore, work is underway to use hyperspectral data to detect the chemical composition of plants, which can be used to detect the nutrient and water status of wheat in irrigated systems. On a smaller scale, NIR hyperspectral imaging can be used to rapidly monitor the application of pesticides to individual seeds for quality control of the optimum dose and homogeneous coverage. Another application in agriculture is the detection of animal proteins in compound feeds to avoid bovine spongiform encephalopathy (BSE), also known as mad-cow disease. Different studies have been done to propose alternative tools to the reference method of detection, (classical microscopy). One of the first alternatives is near infrared microscopy (NIR), which combines the advantages of microscopy and NIR. In 2004, the first study relating this problem with hyperspectral imaging was published. Hyperspectral libraries that are representative of the diversity of ingredients usually present in the preparation of compound feeds were constructed. These libraries can be used together with chemometric tools to investigate the limit of detection, specificity and reproducibility of the NIR hyperspectral imaging method for the detection and quantification of animal ingredients in feed. HSI cameras can also be used to detect stress from heavy metals in plants and become an earlier and faster alternative to post-harvest wet chemical methods. Waste sorting and recycling Hyperspectral imaging can provide information about the chemical constituents of materials which makes it useful for waste sorting and recycling. It has been applied to distinguish between substances with different fabrics and to identify natural, animal and synthetic fibers. HSI cameras can be integrated with machine vision systems and, via simplifying platforms, allow end-customers to create new waste sorting applications and other sorting/identification applications. A system of machine learning and hyperspectral camera can distinguish between 12 different types of plastics such as PET and PP for automated separation of waste of, as of 2020, highly unstandardized plastics products and packaging. Eye care Researchers at the Université de Montréal are working with Photon etc. and Optina Diagnostics to test the use of hyperspectral photography in the diagnosis of retinopathy and macular edema before damage to the eye occurs. The metabolic hyperspectral camera will detect a drop in oxygen consumption in the retina, which indicates potential disease. An ophthalmologist will then be able to treat the retina with injections to prevent any potential damage. Food processing In the food processing industry, hyperspectral imaging, combined with intelligent software, enables digital sorters (also called optical sorters) to identify and remove defects and foreign material (FM) that are invisible to traditional camera and laser sorters. By improving the accuracy of defect and FM removal, the food processor’s objective is to enhance product quality and increase yields. Adopting hyperspectral imaging on digital sorters achieves non-destructive, 100 percent inspection in-line at full production volumes. The sorter’s software compares the hyperspectral images collected to user-defined accept/reject thresholds, and the ejection system automatically removes defects and foreign material. The recent commercial adoption of hyperspectral sensor-based food sorters is most advanced in the nut industry where installed systems maximize the removal of stones, shells and other foreign material (FM) and extraneous vegetable matter (EVM) from walnuts, pecans, almonds, pistachios, peanuts and other nuts. Here, improved product quality, low false reject rates and the ability to handle high incoming defect loads often justify the cost of the technology. Commercial adoption of hyperspectral sorters is also advancing at a fast pace in the potato processing industry where the technology promises to solve a number of outstanding product quality problems. Work is underway to use hyperspectral imaging to detect “sugar ends,” “hollow heart” and “common scab,” conditions that plague potato processors. Mineralogy Geological samples, such as drill cores, can be rapidly mapped for nearly all minerals of commercial interest with hyperspectral imaging. Fusion of SWIR and LWIR spectral imaging is standard for the detection of minerals in the feldspar, silica, calcite, garnet, and olivine groups, as these minerals have their most distinctive and strongest spectral signature in the LWIR regions. Hyperspectral remote sensing of minerals is well developed. Many minerals can be identified from airborne images, and their relation to the presence of valuable minerals, such as gold and diamonds, is well understood. Currently, progress is towards understanding the relationship between oil and gas leakages from pipelines and natural wells, and their effects on the vegetation and the spectral signatures. Recent work includes the PhD dissertations of Werff and Noomen. Surveillance Hyperspectral surveillance is the implementation of hyperspectral scanning technology for surveillance purposes. Hyperspectral imaging is particularly useful in military surveillance because of countermeasures that military entities now take to avoid airborne surveillance. The idea that drives hyperspectral surveillance is that hyperspectral scanning draws information from such a large portion of the light spectrum that any given object should have a unique spectral signature in at least a few of the many bands that are scanned. Hyperspectral imaging has also shown potential to be used in facial recognition purposes. Facial recognition algorithms using hyperspectral imaging have been shown to perform better than algorithms using traditional imaging. Traditionally, commercially available thermal infrared hyperspectral imaging systems have needed liquid nitrogen or helium cooling, which has made them impractical for most surveillance applications. In 2010, Specim introduced a thermal infrared hyperspectral camera that can be used for outdoor surveillance and UAV applications without an external light source such as the sun or the moon. Astronomy In astronomy, hyperspectral imaging is used to determine a spatially-resolved spectral image. Since a spectrum is an important diagnostic, having a spectrum for each pixel allows more science cases to be addressed. In astronomy, this technique is commonly referred to as integral field spectroscopy, and examples of this technique include FLAMES and SINFONI on the Very Large Telescope, but also the Advanced CCD Imaging Spectrometer on Chandra X-ray Observatory uses this technique. Chemical imaging Soldiers can be exposed to a wide variety of chemical hazards. These threats are mostly invisible but detectable by hyperspectral imaging technology. The Telops Hyper-Cam, introduced in 2005, has demonstrated this at distances up to 5 km. Environment Most countries require continuous monitoring of emissions produced by coal and oil-fired power plants, municipal and hazardous waste incinerators, cement plants, as well as many other types of industrial sources. This monitoring is usually performed using extractive sampling systems coupled with infrared spectroscopy techniques. Some recent standoff measurements performed allowed the evaluation of the air quality but not many remote independent methods allow for low uncertainty measurements. Civil engineering Recent research indicates that hyperspectral imaging may be useful to detect the development of cracks in pavements which are hard to detect from images taken with visible spectrum cameras. Biomedical imaging Hyperspectral imaging has also been used to detect cancer, identify nerves and analyze bruises. Data compression In February 2019, an organization founded by the world's major space industries, the Consultative Committee for Space Data Standards (CCSDS), approved a standard for both lossless and near-lossless compression of multispectral and hyperspectral images (CCSDS 123). Based on NASA's fast-lossless algorithm, it requires very low memory and computational resources compared to alternatives, such as JPEG 2000. Commercial implementations of CCSDS 123 include: The European Space Agency's SHyLoC IP core, for lossless compression of up to 1 Gbps. Metaspectral for both lossless and near-lossless compression, achieving throughputs of over 30 Gbps. Advantages and disadvantages The primary advantage to hyperspectral imaging is that, because an entire spectrum is acquired at each point, the operator needs no prior knowledge of the sample, and postprocessing allows all available information from the dataset to be mined. Hyperspectral imaging can also take advantage of the spatial relationships among the different spectra in a neighbourhood, allowing more elaborate spectral-spatial models for a more accurate segmentation and classification of the image. The primary disadvantages are cost and complexity. Fast computers, sensitive detectors, and large data storage capacities are needed for analyzing hyperspectral data. Significant data storage capacity is necessary since uncompressed hyperspectral cubes are large, multidimensional datasets, potentially exceeding hundreds of megabytes. All of these factors greatly increase the cost of acquiring and processing hyperspectral data. Also, one of the hurdles researchers have had to face is finding ways to program hyperspectral satellites to sort through data on their own and transmit only the most important images, as both transmission and storage of that much data could prove difficult and costly. As a relatively new analytical technique, the full potential of hyperspectral imaging has not yet been realized. See also Acousto-optic tunable filter Airborne real-time cueing hyperspectral enhanced reconnaissance Cathodoluminescence Full spectral imaging HyMap, a widely used hyperspectral imaging sensor Liquid crystal tunable filter Metamerism (color), the perceptual equivalence that hyperspectral imaging overcomes Multispectral image Sensor fusion Video spectroscopy References External links ASTER Spectral Library (compilation of over 2400 spectra of natural and man made materials) Sample Hyperspectral (AVIRIS) images from JPL Satellite meteorology Materials science Imaging Remote sensing Infrared imaging Surveillance Spectroscopy Infrared spectroscopy Military electronics Satellite imaging sensors

3929316

https://en.wikipedia.org/wiki/Brian%20G.%20W.%20Manning

Brian G. W. Manning

Brian George William Manning (14 May 1926 – 10 November 2011) was an English astronomer who discovered 19 minor planets. He was born in 1926 in Birmingham. He constructed his first mirror from a piece of glass that a World War II bomb blew out of the roof of the factory where his father worked. He began as an engineering draughtsman but later became a metrologist at the University of Birmingham. In the late 1950s, he constructed an interference-controlled ruling machine in a home workshop, which was able to rule high-quality 3 by 2 inch gratings. In 1990, he received the H. E. Dall prize of the BAA. Discoveries Brian Manning is credited by the Minor Planet Center with the discovery of 19 minor planets he made at Stakenbridge Observatory (494), near Kidderminster, England, between 1989 and 1997. All of his discovered minor planets are asteroids of the main-belt: References Hurst, Guy M. 'Brian George William Manning' in the Journal of the British Astronomical Association, April 2012, Volume 22, Number 2. External links IAUC 3104, periodic comet Chernykh (1977l), 1926 births 2011 deaths 20th-century British astronomers Academics of the University of Birmingham Discoverers of minor planets Discoveries by Brian G. W. Manning Metrologists People from Handsworth, West Midlands

3930637

https://en.wikipedia.org/wiki/Alois%20von%20Beck%20Widmanst%C3%A4tten

Alois von Beck Widmanstätten

Count Alois von Beckh Widmanstätten (13 July 1754 – 10 June 1849) was an Austrian printer and mineralogist. His name is sometimes given as Alois von Beckh-Widmannstätten or Aloys Joseph Franz Xaver Beck Edler von Widmanstätten. He is known for recognizing a unique pattern of cross-hatching lines on the surface of iron-rich meteorites, now called Widmanstätten patterns, resulting from the cooling and crystallization of interstitial minerals. A crater on the Moon is named after Widmanstätten. Working life Von Widmanstätten was born in Graz where his family had a printing business and was trained in the printing art by his father. His family owned exclusive printing rights in the Steiermark province, but this was lost in 1784 and Alois sold the business in 1807. In 1804, he ran a spinning mill in Pottendorf, Austria. In 1806 he was invited by the emperor to head a newly founded Imperial Technical Museum or Fabriksproduktenkabinett begun in 1807. From 1808, he was the director of the Imperial Porcelain works in Vienna. Widmanstätten pattern While working at the Fabriksproduktenkabinett, he began to examine iron meteorites along with Karl von Schreibers. They polished and etched the surface of iron meteorites with dilute nitric acid and noticed that it revealed a patterning of cross-hatched lines that came to be called Widmanstätten patterns. He examined by flame-heating a slab of Hraschina meteorite. The different iron alloys of meteorites oxidized at different rates during heating, causing color and luster differences. In 1813 he made imprints of these structures with printing ink and paper. These were unpublished during his life. A print of the structures from the Hraschina meteorite collected in 1751 was used in a supplement to the book Über Feuer-Meteore, und über die mit denselben herabgefallenen Massen of Ernst Chladni which was published by Schreibers in 1820 as Beiträge zur Geschichte und Kenntniss meteorischer Stein und Metallmassen. Schreibers named the structure after Widmanstätten and the term is widely used in metallurgy. The Widmanstätten pattern had been observed previously, in 1804, by the English mineralogist William (Guglielmo) Thomson. During the period that he spent in Naples, he discovered these figures by bathing a Krasnojarsk meteorite in nitric acid for the purpose of removing rust and he published his discovery in French in the Bibliothèque Britannique, but Thomson's publication escaped Schreibers' notice. Named after him Widmanstätten patterns of iron meteorites The crater Widmannstätten on the Moon 21564 Widmanstätten asteroid See also William Thomson (mineralogist) Meteorite Notes 1753 births 1849 deaths Austrian scientists Counts of Austria Meteorite researchers Austrian mineralogists Austrian metallurgists

3931064

https://en.wikipedia.org/wiki/Fallen%20Astronaut

Fallen Astronaut

Fallen Astronaut is a aluminum sculpture created by Belgian artist Paul Van Hoeydonck. It is a stylized figure of an astronaut in a spacesuit, intended to commemorate the astronauts and cosmonauts who have died in the advancement of space exploration. It was commissioned and placed on the Moon by the crew of Apollo 15 at Hadley Rille on August 2, 1971, UTC, next to a plaque listing 14 names of those who died up to that time. The statue lies on the ground among several footprints. The crew kept the memorial's existence a secret until after completing their mission. After public disclosure, the National Air and Space Museum requested a replica of the statue. Controversy soon followed as Van Hoeydonck claimed a different understanding of the agreement with the astronauts and attempted to sell up to 950 copies of the figure. He finally relented under pressure from NASA, which had a strict policy against commercial exploitation of the US government space program. Commission Before his Apollo 15 lunar mission, astronaut David Scott met Belgian painter and printmaker Paul Van Hoeydonck at a dinner party. They agreed that Van Hoeydonck would create a small statuette for Scott to place on the Moon, though their recollections of the details differ. Scott's purpose was to commemorate those astronauts and cosmonauts who had died in the furtherance of space exploration. He designed and separately made a plaque listing 14 American and Soviet names. Van Hoeydonck was given a set of design specifications: the sculpture was to be lightweight but sturdy, capable of withstanding the temperature extremes of the Moon; it could not be identifiably male or female, nor of any identifiable ethnic group. According to Scott, it was agreed Van Hoeydonck's name would not be made public to avoid the commercial exploitation of the US government's space program. Scott got permission from top NASA management before the mission to take the statue aboard his spacecraft. Still, he only disclosed it publicly in a post-mission press conference. Van Hoeydonck gives a different account of the agreement: according to an interview in the Belgian newspaper Le Soir, the statue was supposed to represent all mankind, not only fallen astronauts or cosmonauts. He claimed he did not know the statue would be used as a memorial for the fallen space-goers, and the name given to the work was neither chosen nor approved by him; he had intended the figure to be left standing upright. He also denies it was agreed he would remain anonymous. Both his and Scott's versions of events are given in an article in Slate magazine in 2013. Placement on the Moon Astronaut David Scott secretly placed the Fallen Astronaut statue on the Moon during the Apollo 15 mission, near the completion of his work on August 2, 1971, along with a plaque bearing the names of eight American astronauts and six Soviet cosmonauts who had died in service: Scott photographed the memorial but waited for a post-mission press conference to disclose its existence. He noted, "Sadly, two names are missing, those of Valentin Bondarenko and Grigori Nelyubov." He explained that the Western world was unaware of their deaths because of the secrecy surrounding the Soviet space program at the time. Also missing was Robert Henry Lawrence Jr., the first black astronaut and a U.S. Air Force officer selected for the Manned Orbiting Laboratory program who was killed in a training accident in 1967. Controversy During their press conference, the crew disclosed the statuette's existence and the National Air and Space Museum requested that a replica be made for public display. The crew agreed that it be displayed "with good taste and without publicity". They gave the replica to the Smithsonian Institution on April 17, 1972, the day after CBS anchorman Walter Cronkite referred to the Fallen Astronaut and plaque as the first art installation on the Moon during the broadcast of the Apollo 16 launch. In May 1972, Scott learned that Van Hoeydonck planned to make and sell more replicas. He believed this would violate the spirit of their agreement and of NASA's policy against commercial exploitation of the space program, and he tried to persuade Van Hoeydonck to refrain. Van Hoeydonck placed a full-page advertisement in the July 1972 issue of Art in America magazine offering 950 replicas of Fallen Astronaut signed by the sculptor, sold by the Waddell Gallery of New York for $750 each, a second edition at a lower, unspecified price, and a catalog edition at $5. Van Hoeydonck retracted his permission for the replicas after receiving complaints from NASA, but not before one was sold. Using a box numbered 200/950 and prepared for the limited edition, a sample figure was sold to a Morgan Stanley investment banker who collected space artifacts and works of art. Van Hoeydonck verified the sale following an investigation that began in 2015 when the piece surfaced on eBay. It was bought by a collector living in the UK. On September 11, 2007, art journalist Jan Stalmans asked Van Hoeydonck how many replicas existed. Van Hoeydonck returned a handwritten response on the letter that 50 copies had been made, most of which were still in his possession unsigned. Replicas In January 2019, Van Hoeydonck and Apollo 15 Command Module Pilot Al Worden announced the sale of a limited edition replica inside a blue acrylic block, as Van Hoeydonck originally intended, which would have allowed the statue to be placed upright on the Moon to "symbolize humanity rising" via space travel. NASA had rejected the acrylic enclosure's inclusion on the flight as a fire hazard. A smaller number of enlarged sculptures are also to be sold. See also List of artificial objects on the Moon List of spaceflight-related accidents and incidents List of extraterrestrial memorials Space Mirror Memorial References Specific General External links Sculpture fabricated at Milgo / Bufkin Transcript of NASA News Release 72-189 (September 15, 1972), describing the origin of Fallen Astronaut and the subsequent controversy Slate article "Sculpture on the Moon" Official NASA photo of Fallen Astronaut on the Moon Apollo 15 Lunar Surface Journal Observatoire du Land Art (transcript of the book Goden & Astronaut, Banana Press, 1972 (statement, articles, photos)) Von Hoeydonck's website Paul Van Hoeydonck works at Whitford Fine Art See some works of Paul Van Hoeydonck 1971 sculptures Aluminium sculptures Apollo 1 Apollo 15 Collection of the Smithsonian Institution Death in art Exploration of the Moon Message artifacts Monuments and memorials Monuments and memorials to explorers Outdoor sculptures Posthumous recognitions Monuments and memorials to Yuri Gagarin David Scott Gus Grissom Ed White (astronaut) 1971 on the Moon Astronauts in art

3934671

https://en.wikipedia.org/wiki/Kosmos%20379

Kosmos 379

Kosmos 379 ( meaning "Cosmos 379") was an unmanned test of the LK (the Soviet counterpart of the Apollo Lunar Module) in Earth orbit. Mission Earth orbit simulated propulsion system operations of a nominal lunar landing mission. Kosmos 379 entered a 192 to 232 km low Earth orbit. After three days it fired its motor to simulate hover and touchdown on the moon, in imitation of a descent to the lunar surface after separation of the Blok D lunar crasher propulsion module. The engine firing changed its orbit from 192 km X 233 km to 196 km X 1206 km (delta-V = 263 m/s). After a simulated stay on the Moon, it increased its speed by 1.518 km/s, simulating ascent to lunar orbit making the final apogee 14,035 km. These main maneuvers were followed by a series of small adjustments simulating rendezvous and docking with the Soyuz 7K-L3. The LK lander tested out without major problems and decayed from orbit on September 21, 1983. Parameters Spacecraft: T2K Mass: 5500 kg Crew: None Launched: November 24, 1970 Landed: Reentered September 21, 1983 Orbit: 192 km References External links Mir Hardware Heritage Mir Hardware Heritage - NASA report (PDF format) Mir Hardware Heritage (wikisource) Kosmos satellites Soviet lunar program 1970 in the Soviet Union Spacecraft launched in 1970

3934870

https://en.wikipedia.org/wiki/Kosmos%20434

Kosmos 434

Kosmos 434 (; meaning Cosmos 434) was the final uncrewed test flight of the Soviet LK Lander. It performed the longest burn of the four uncrewed LK Lander tests, validating the backup rocket engine of the LK's Blok E propulsion system. It finished in a 186 km by 11,804 km orbit. This test qualified the lander as flightworthy. The LK was the only element of the Soviet human lunar programs that reached this status. In 1980-81 there were fears that it might carry nuclear fuel. When it reentered over Australia on August 22, 1981 the Soviet Foreign Ministry in Australia admitted that Kosmos 434 was an “experiment unit of a lunar cabin,” or lunar lander. See also 1971 in spaceflight References External links Mir Hardware Heritage Mir Hardware Heritage - NASA report (PDF format) Mir Hardware Heritage (wikisource) Kosmos 0434 Soviet lunar program 1971 in the Soviet Union Australia–Soviet Union relations Spacecraft launched in 1971

3935006

https://en.wikipedia.org/wiki/Kosmos%20496

Kosmos 496

Kosmos 496 ( meaning Cosmos 496) was an unmanned test of the redesigned Soyuz ferry. The redesign may have involved changes to the Salyut/Soyuz hatch. It did not dock with any space station. After the Soyuz 11 disaster the third seat was removed because the space was need for the two crewmen in space suits and their equipment. Kosmos 496 retained its solar arrays. Mission parameters Spacecraft: Soyuz-7K-T Mass: 6800 kg Crew: None Launched: June 26, 1972. Launch site: Baikonur. Orbit 195 x 343km. Inclination 51 degrees. Landed: July 2, 1972 References Mir Hardware Heritage Mir Hardware Heritage - NASA report (PDF format) Mir Hardware Heritage (wikisource) 1972 in spaceflight Kosmos 0496 Kosmos 0496 1972 in the Soviet Union Spacecraft launched in 1972

3935197

https://en.wikipedia.org/wiki/Kosmos%20573

Kosmos 573

Kosmos 573 ( meaning Cosmos 573) was an unmanned test of the Soyuz without solar arrays in 1973. It did not dock with a space station. Mission parameters Spacecraft: Soyuz-7K-T Mass: Crew: None Launched: June 15, 1973 Landed: June 17, 1973 External links Mir Hardware Heritage Mir Hardware Heritage - NASA report (PDF format) Mir Hardware Heritage (wikisource) References Kosmos 0573 1973 in the Soviet Union Spacecraft launched in 1973

3935306

https://en.wikipedia.org/wiki/Kosmos%20613

Kosmos 613

Kosmos 613 ( meaning Cosmos 613) was a long-duration orbital storage test of the Soyuz Ferry in preparation for long stays attached to a space station. Mission parameters Spacecraft: Soyuz-7K-T Mass: 6800 kg Crew: seeds Launched: November 30, 1973 Landed: January 29, 1974 See also 1973 in spaceflight References External links Mir Hardware Heritage Mir Hardware Heritage - NASA report (PDF format) Mir Hardware Heritage (wikisource) Kosmos satellites Soyuz uncrewed test flights 1973 in the Soviet Union Spacecraft launched in 1973

3935349

https://en.wikipedia.org/wiki/Kosmos%20638

Kosmos 638

Kosmos 638 () was an uncrewed test of the 1975 Apollo–Soyuz Test Project Soyuz. It carried an APAS-75 androgynous docking system. This was followed by another uncrewed test of this spacecraft type, Kosmos 672. It was a Soyuz 7K-TM spacecraft. When the air was released from the orbital module (which is ejected before re-entry of the capsule) it caused unexpected motions with the spacecraft. This led to the next test also being uncrewed. Mission parameters Spacecraft: Soyuz-7K-TM №71 Mass: 6510 to 6680 kg Crew: None Launched: April 3, 1974 Landed: April 13, 1974 References Mir Hardware Heritage Mir Hardware Heritage (NASA report RP 1357) (PDF format) Mir Hardware Heritage (NASA report RP 1357) (Wikisource) Kosmos 0638 1974 in the Soviet Union Spacecraft launched in 1974 Apollo–Soyuz Test Project Soyuz uncrewed test flights

3935377

https://en.wikipedia.org/wiki/Kosmos%20672

Kosmos 672

Kosmos 672 ( meaning Cosmos 672) was the second uncrewed test of the ASTP Soyuz spacecraft. Also had APAS-75 androgynous docking system. This was preceded by another uncrewed test of this spacecraft type, Kosmos 638. It was a Soyuz 7K-TM spacecraft. Mission parameters Spacecraft: Soyuz 7K-TM Mass: 6510 to 6680 kg Crew: None Launched: August 12, 1974 Landed: August 18, 1974 References Mir Hardware Heritage Mir Hardware Heritage - NASA report (PDF format) Mir Hardware Heritage (wikisource) Kosmos 0672 1974 in the Soviet Union Spacecraft launched in 1974 Soyuz uncrewed test flights Apollo–Soyuz Test Project

3935411

https://en.wikipedia.org/wiki/Kosmos%201001

Kosmos 1001

Kosmos 1001 ( meaning Cosmos 1001) was a redesigned Soviet Soyuz T spacecraft that was flown on an unmanned test in 1978. The spacecraft was the upgraded Soyuz for Salyut-6 and Salyut-7. This Kosmos flight, launched from Baikonur, was the first orbital tests of the Soyuz T design. Several maneuvers were tested. Mission parameters Spacecraft: Soyuz-7K-ST. Orbit: 200 x 228km. Inclination: 52 degrees. Mass: 6680 kg. Crew: None. Launched: April 4, 1978. Landed: April 15, 1978. References External links Astronautix web page Kosmos satellites Spacecraft launched in 1978 1978 in spaceflight 1978 in the Soviet Union Soyuz uncrewed test flights

3935423

https://en.wikipedia.org/wiki/Kosmos%201074

Kosmos 1074

Kosmos 1074 ( meaning Cosmos 1074) was a Soviet unmanned long-duration test flight of the Soyuz-T spacecraft launched on January 31, 1979 and de-orbited on April 1, 1979. Mission parameters Spacecraft: Soyuz 7K-ST Mass: 6450 kg Crew: None Launched: January 31, 1979 Landed: April 1, 1979 References Kosmos satellites 1979 in the Soviet Union Spacecraft launched in 1979 Soyuz uncrewed test flights

3938164

https://en.wikipedia.org/wiki/At%20the%20Earth%27s%20Core%20%28film%29

At the Earth's Core (film)

At the Earth's Core is a 1976 British-American fantasy-science fiction film produced by Britain's Amicus Productions. The film was directed by Kevin Connor and stars Doug McClure, Peter Cushing and Caroline Munro. It was filmed in Technicolor, and is based on the 1914 fantasy novel At the Earth's Core by Edgar Rice Burroughs, the first book of his Pellucidar series, in token of which the film is also known as Edgar Rice Burroughs' At the Earth's Core. The original music score was composed by Mike Vickers. Plot Dr. Abner Perry (Peter Cushing), a British Victorian scientist, and his US financier David Innes (Doug McClure) make a test run of their Iron Mole drilling machine in a Welsh mountain. While drilling underground, the extreme heat emanating from the magma around the Mole knocks the duo out and makes them temporarily loose control over where the machine is taking them. After it passes through the magma crust and gets closer to the Earth's core, the temperature inside the Mole starts to lower, and the duo regains consciousness. Perry and Innes eventually reach a surface where they can safely get out. The two quickly notice they are in a strange land filled with flora and fauna pf prehistoric times. They are quickly captured by the Sagoths, ape-like creatures, who aim enslave to enslave every human tribe there. The Sagoths are themselves ruled by a species of giant telepathic flying reptiles, the Mahars (Pterodactyls with parrot-like beaks). The Mahars have the power of mind control. David falls for the beautiful slave girl Princess Dia (Caroline Munro). She is eventually chosen as a sacrificial victim in the Mahar city, while David is put to work in the magma mines and Perry visits the library. Worried about Dia, David incites and riot within the mine and gets eventually captured with Ra, another rebellious slave. The two are sent to the arena where a crowd of slaves watch. The Mahars send a giant dinausar to kill the duo, but with help of Perry (who shouts about the creature's weak point from the crowd), David and Ra survive. They not only kill the dinosaur but murder a Mahar as well, earning the respect of the slaves. David and Ra must rally the surviving human slaves to rebel and win their freedom. To achieve this, Innes, Ra and Dia organize the oppressed tribes and helps them work together while Perry teaches them how to build and use bows and arrows. Their combined efforts are eventually successful. Together, the humans manage to kill the Mahars and subdue their minions. After repairing the Mole, Perry and Innes prepare to go back to the surface with Dia. However, despite how much Dia loves Innes, she believes she will not fit in the surface world, like Innes does not fit in her own world. A hurt Innes accepts her reasoning and decides to return alone with Perry to the United Kingdom. Cast Doug McClure as David Innes Peter Cushing as Dr. Abner Perry Caroline Munro as Princess Dia Cy Grant as Ra Godfrey James as Ghak the Hairy One Sean Lynch as Hoojah Keith Barron as Dowsett Helen Gill as Maisie Anthony Verner as Gadsby Robert Gillespie as Photographer Michael Crane as Jubal Bobby Parr as Sagoth Chief Andee Cromarty as Girl Slave Production The film was made following the success of The Land That Time Forgot. Kevin Connor later recalled, "we tried to get the beasts bigger so as to interact better with the actors – more one on one. We had a somewhat bigger budget thanks to the success of ‘Land.’ The beasts were specially designed so that small stunt guys could work inside the suits in a crouched position and on all-fours. Needless to say it was very cramped and the stunt guys had to take frequent breathers. Some worked better than others – but we were experimenting and trying something different." Release The film premiered at the Marble Arch Odeon in London on 15 July 1976. Reception The film was popular, becoming the 18th most profitable British film of 1976. It made a profit. Amongst contemporary critics, however, The New York Times was not impressed: "All the money used to make 'At the Earth's Core' seems to have been spent on building monsters with parrotlike beaks that open, close, and emit a steady squawling as if someone were vacuuming next door. Close up, the monsters look like sections of rough concrete wall and the decision to film them in closeup is only one example of the total lack of talent or effort with which the picture is made...the movie is a kind of no-talent competition in which the acting, the script, the direction and the camera-work vie for last place." More recently, in more positive vein, BFI Screenonline said, "Extravagant, colourful and thoroughly preposterous, At the Earth's Core is utterly without pretension but has the exuberant charm of the best of its decade." The film was featured in the season finale of the revived Mystery Science Theater 3000, the show's eleventh season overall, released on April 14, 2017, through Netflix. Featured animals Homo habilis, or is it Paranthropus? (Sagoth): The furry servants of the Mahars who are lighter in build than a gorilla. Inostrancevia (Lato) Mastodonsaurus (In the movie, A fire-breathing Amphibian) Megacerops (identified by its synonym Brontotherium): Incorrectly having a pair of horns on its head and razor-sharp teeth. Psittacosaurus Rhamphorhynchus (Mahar): Incorrectly having a bird-like beak, dragon-like wings, and the size of an oversized Vulture. Tanystropheus (Hydrophidian): Poster only See also The People That Time Forgot (film) Journey to the Center of the Earth (1959 film) Journey to the Center of the Earth (2008 direct-to-video film) – A direct-to-DVD American film sharing similarities with this film References External links MGM – Official Site At the Earth's Core at BFI Screenonline 1976 films 1970s fantasy adventure films 1970s science fiction films British fantasy adventure films British science fiction films Films based on American novels 1970s English-language films American International Pictures films Amicus Productions films Films directed by Kevin Connor Films set in the Victorian era Films based on works by Edgar Rice Burroughs Films set in Wales Films shot at Pinewood Studios Films about the Hollow Earth Lost world films Pellucidar Travel to the Earth's center British science fantasy films Films about dinosaurs English-language Welsh films 1970s British films Films scored by Mike Vickers Films about princesses Films about slavery

3939920

https://en.wikipedia.org/wiki/78P/Gehrels

78P/Gehrels

78P/Gehrels, also known as Gehrels 2, is a Jupiter-family periodic comet in the Solar System with a current orbital period of 7.22 years. It was discovered by Tom Gehrels at the Lunar and Planetary Laboratory, Arizona, USA on photographic plates exposed between 29 September and 5 October 1973 at the Palomar Observatory. It had a brightness of apparent magnitude of 15. Brian G. Marsden computed the parabolic and elliptical orbits which suggested an orbital period of 8.76 years, later revising the data to give a perihelion date of 30 November 1963 and orbital period of 7.93 years. The comet's predicted next appearance in 1981 was observed by W. and A. Cochran at the McDonald Observatory, Texas on 8 June 1981. It was observed again in 1989 and in 1997, when favourable conditions meant that brightness increased to magnitude 12. It has subsequently been observed in 2004 when it reached magnitude 10, 2012, and 2018. Outward migration Comet 78P/Gehrels' aphelion (furthest distance from the Sun) of 5.4AU is in the zone of control of the giant planet Jupiter and the orbit of the comet is frequently perturbed by Jupiter. On September 15, 2029, the comet will pass within 0.018 AU (2.7 million kilometers) of Jupiter and be strongly perturbed. By the year 2200, the comet will have a centaur-like orbit with a perihelion (closest distance to the Sun) near Jupiter. This outward migration from a perihelion of 2AU to a perihelion of ~5AU could cause the comet to go dormant. See also List of numbered comets References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 78P/Gehrels – Minor Planet Center 78P/Gehrels 2 (2012) 78P at Kronk's Cometography Lightcurve (Artyom Novichonok) 78P as seen by 10" GRAS-04 on 2011-05-03 (120 sec x 6) 78P as seen by Schmidt-Cassegrain on 2011 08 06 (3 x 748 sec) and 2011 08 09 (6 x 600 sec) Periodic comets 0078 Comets in 2012 Comets in 2019 19730929

3940054

https://en.wikipedia.org/wiki/84P/Giclas

84P/Giclas

84P/Giclas is a periodic comet in the Solar System. The comet nucleus is estimated to be 1.8 kilometers in diameter. In 1995 precovery images from three nights in September 1931 by Clyde W. Tombaugh were located. During the 2020 apparition it was not more than 60 degrees from the Sun until September 2020. On 11 June 2033 the comet will pass from the asteroid 4 Vesta. The nucleus of the comet has a radius of 0.90 ± 0.05 kilometers, assuming a geometric albedo of 0.04. References External links 84P/Giclas – Seiichi Yoshida @ aerith.net 84P at Kronk's Cometography Periodic comets 0084 Comets in 2013 19780908

3944986

https://en.wikipedia.org/wiki/SUNSAT

SUNSAT

The Stellenbosch UNiversity SATellite or SUNSAT (COSPAR 1999-008C) was the first miniaturized satellite designed and manufactured in South Africa. It was launched aboard a Delta II rocket from the Vandenberg Air Force Base on 23 February 1999 to become the first launched South African satellite. Sunsat was built by post-graduate engineering students at the University of Stellenbosch. Its AMSAT designation was SO-35 (Sunsat Oscar 35). Last contact by ground control with SUNSAT was on 19 January 2001 and on 1 February 2001 the end of SUNSAT's functional life in orbit was announced. The satellite operated in orbit for nearly 2 years. It is predicted to reenter the atmosphere after about 30 years from launch. Specifications SUNSAT satellite specifications: Size: 45 x 45 x 60 cm Mass: 64 kg Launcher: Delta II rocket, Mission P-91 Program cost: US $5M (Approximate); the launch was free of charge as SUNSAT was orbited as a secondary payload. The primary payload of the launch was ARGOS, and the Danish Orsted satellite was another secondary payload. Planned lifetime: 4–5 years (NiCad Battery pack life) Main payloads: Amateur radio communications Data interchange Stereo multispectral imager Attitude control: Gravity gradient and magnetorquers, reaction wheels when imaging Accuracy: 3 mrad pitch/roll, 6 mrad yaw 2 Micro Particle Impact Detectors were included as part of experiments conducted in orbit A team (Zaahied Cassim and Rashid Mohamed) from Peninsula Technikon designed and built circuits for both their own piezo film technology and NASA supplied capacitive sensors. SSC 25636 Pushboom imager Ground pixel size: 15 m x 15 m Image width: 51.8 km References Stellenbosch University Amateur radio satellites Spacecraft launched in 1999 Spacecraft launched by Delta II rockets First artificial satellites of a country Space program of South Africa

3946776

https://en.wikipedia.org/wiki/Ian%20P.%20Griffin

Ian P. Griffin

Ian P. Griffin (born 1966) is a New Zealand astronomer, discoverer of minor planets and a public spokesman upon scientific matters. He is currently the Director of Otago Museum, Dunedin, New Zealand. Griffin was the CEO of Science Oxford, in Oxford, United Kingdom, and the former head of public outreach at NASA's Space Telescope Science Institute. Biographical information Griffin began his professional life at University College London where he decided to pursue a career combining both astronomical research and public outreach. He was director of the Armagh Planetarium from 1990 to 1995. He then worked at Astronaut Memorial Planetarium and Observatory at Brevard Community College in Cocoa, Florida and Auckland Observatory in New Zealand before accepting the position as head of public outreach at the Space Telescope Science Institute in Baltimore, US. From 2004 to 2007 Griffin was director of the Museum of Science and Industry in Manchester. Griffin studied and trained to be an astronomer. He obtained his PhD in astronomy from University College London, in 1991. Griffin has a strong Twitter presence and regularly updates followers with photos of the Aurora Australis and of other astronomical phenomena. Significant achievements In his time at Space Telescope, Griffin contributed to the observation and study of a scientifically significant binary asteroid system, known as 1998 WW31. This was only the second such binary system discovered in the Kuiper belt (the other being the Pluto and Charon system) and provided valuable data helping astronomers understand the mass and behaviour of objects in the Kuiper belt. Via search programmes using small telescopes, Griffin also discovered 26 numbered minor planets between 1998 and 2001. Three of his discoveries were made in collaboration with Australian astronomer Nigel Brady. His discovery include: 10924 Mariagriffin, named after his wife Maria (b. 1962) 23990 Springsteen, named after American musician Bruce Springsteen 33179 Arsènewenger, named after Arsène Wenger, the former manager of Griffin's favourite football team, Arsenal However the Mars-crossing asteroid 4995 Griffin is unrelated to him, as it was named after Griffin Swanson the son of its discoverer Steven Roger Swanson. In 2015, Griffin was awarded the New Zealand Prime Minister's Science Communication Prize, worth NZD 100,000, for his work at Otago Museum. He was elected a Companion of Royal Society Te Apārangi in 2019. References 21st-century New Zealand astronomers Alumni of University College London 20th-century British astronomers Discoverers of minor planets Living people People associated with Otago Museum 1966 births Companions of the Royal Society of New Zealand

3946940

https://en.wikipedia.org/wiki/Alan%20Stern

Alan Stern

Sol Alan Stern (born November 22, 1957) is an American engineer and planetary scientist. He is the principal investigator of the New Horizons mission to Pluto and the Chief Scientist at Moon Express. Stern has been involved in 24 suborbital, orbital, and planetary space missions, including eight for which he was the mission principal investigator. One of his projects was the Southwest Ultraviolet Imaging System, an instrument which flew on two space shuttle missions, STS-85 in 1997 and STS-93 in 1999. Stern has also developed eight scientific instruments for planetary and near-space research missions and has been a guest observer on numerous NASA satellite observatories, including the International Ultraviolet Explorer, the Hubble Space Telescope, the International Infrared Observer and the Extreme Ultraviolet Observer. Stern was executive director of the Southwest Research Institute's Space Science and Engineering Division until becoming Associate Administrator of NASA's Science Mission Directorate in 2007. He resigned from that position after nearly a year. His research has focused on studies of our solar system's Kuiper belt and Oort cloud, comets, the satellites of the outer planets, Pluto, and the search for evidence of planetary systems around other stars. He has also worked on spacecraft rendezvous theory, terrestrial polar mesospheric clouds, galactic astrophysics, and studies of tenuous satellite atmospheres, including the atmosphere of the Moon. Life and career Stern was born in New Orleans, Louisiana to Jewish parents Joel and Leonard Stern. He graduated from St. Mark's School of Texas in 1975. He then attended the University of Texas, Austin, where he received his bachelor's degrees in physics & astronomy and his master's degrees in aerospace engineering and planetary atmospheres. He earned a doctorate in astrophysics and planetary science from the University of Colorado, Boulder. From 1983 to 1991, Stern held positions at the University of Colorado in the Center for Space and Geoscience Policy, the office of the vice president for Research, and the Center for Astrophysics and Space Astronomy. He received his doctorate in 1989. From 1991 to 1994 he was the leader of Southwest Research Institute's Astrophysical and Planetary Sciences group and was chair of NASA's Outer Planets Science Working Group. From 1994 to 1998 he was the leader of the Geophysical, Astrophysical, and Planetary Science section in Southwest Research Institute's Space Sciences Department, and from 1998 to 2005 he was the director of the Department of Space Studies at Southwest Research Institute. In 1995 he was selected to be a Space Shuttle mission specialist finalist, and in 1996 he was a candidate Space Shuttle payload specialist but did not have the opportunity to fly on the Space Shuttle. In 2007, Stern was listed among Time magazine's 100 Most Influential People in The World. On August 27, 2008, Stern was elected to the board of directors of the Challenger Center for Space Science Education. In 2015, Stern was the recipient of Smithsonian Magazine'''s American Ingenuity Award in the Physical Sciences category. On October 7, 2016, Stern was inducted into the Colorado Space Hall of Fame. Inspiration for Pluto/Kuiper belt mission On June 14, 2007, in an address to the Smithsonian Institution for their "Exploring the Solar System Lecture Series", Stern commented on the New Horizons mission: Private sector experience After completing a master's degree in aerospace engineering Stern spent seven years as an aerospace systems engineer, concentrating on spacecraft and payload systems at the NASA Johnson Space Center, Martin Marietta Aerospace, and the Laboratory for Atmospheric and Space Physics at the University of Colorado. Stern is currently active as a consultant for private sector space efforts and has stated: On June 18, 2008, Stern joined Odyssey Moon Limited (Isle of Man), a private industry effort, as a part-time Science Mission Director/consultant in their efforts to launch a robotic mission to the Earth's Moon by participating in the $30 Million Google Lunar X-Prize competition. In December 2008, Stern joined Blue Origin, a company that was founded by Amazon.com's Jeff Bezos as an independent representative for research and education Missions. The company has stated that its objective is to develop a new vertical-take-off, vertical-landing vehicle known as New Shepard that is designed to take a small number of astronauts on a sub-orbital journey into space and reduce the cost of space transportation. The company is located in Kent, Washington and has flight tested some hardware. In 2012, Stern co-founded Uwingu. Space science mission Stern has experience in instrument development, concentrating on ultraviolet technologies. Stern is a principal investigator (PI) in NASA's UV sounding rocket program, and was the project scientist on a Shuttle-deployable SPARTAN astronomical satellite. He was the PI of the advanced, miniaturized HIPPS Pluto breadboard camera/IR spectrometer/UV spectrometer payload for the NASA/Pluto-Kuiper Express mission, and he is the PI of the PERSI imager/spectrometer payload on NASA's New Horizons Pluto mission. Stern is also the PI of the ALI CE UV Spectrometer for the ESA/NASA Rosetta comet orbiter. He was a member of the New Millennium Deep Space 1 (DS1) mission science team, and is a Co-investigator on both the ESA SPICAM Mars UV spectrometer launched on Mars Express, and the Hubble Space Telescope Cosmic Origins Spectrograph (COS) installed in 2009. He is the PI of the SWUIS ultraviolet imager, which has flown two Shuttle missions, and the SWUIS-A airborne astronomical facility. In this capacity, Stern has flown numerous WB-57 and F-18 airborne research astronomy missions. Stern and his colleague, Dr. Daniel Durda, have been flying on the modified F/A-18 Hornet with a sophisticated camera system called the Southwest Ultraviolet Imaging System (SWUIS). They use the camera to search for a hypothetical group of asteroids (Vulcanoids) between the orbit of Mercury and the Sun that are so elusive and hard to see that scientists are not sure they exist. NASA experience Stern has served on various NASA committees, including the Lunar Exploration Science Working Group (LExSWG) and the Discovery Program Science Working Group (DPSWG), the Solar System Exploration Subcommittee (SSES), the New Millennium Science Working Group (NMSWG), and the Sounding Rocket Working Group (SRWG). He was Chair of NASA's Outer Planets Science Working Group (OPSWG) from 1991 to 1994 and served as a panel member for the National Research Council's 2003-2013 Decadal Survey on planetary science. Stern is a member of the AAAS, the AAS, and the AGU. NASA Associate Administrator Stern was appointed NASA's Associate Administrator for the Science Mission Directorate, essentially NASA's top-ranking official for science, in April 2007. In this position Stern directed a organization with 93 separate flight missions and a program of over 3,000 research grants. During his tenure a record 10 major new flight projects were started and deep reforms of the research and also the education and public outreach programs were put in place. Stern's style was characterised as "hard-charging" as he pursued a reform-minded agenda. He "made headlines for trying to keep agency missions on schedule and under budget" but faced "internal battles over funding". He was credited with making "significant changes that have helped restore the importance of science in NASA's mission". On March 26, 2008, it was announced that Stern had resigned his position the previous day, effective April 11. He was replaced by Ed Weiler, who was to serve his second stint in the position. The resignation occurred on the same day that NASA Chief Michael D. Griffin overruled a decrease in funding for the Mars Exploration Rovers and Mars Odyssey missions that was intended to free up funds needed for the upcoming Mars Science Laboratory. NASA officials would neither confirm nor deny a connection between the two events. Stern left to avoid cutting healthy programs and basic research in order to cover cost overruns. He believed that cost overruns in the Mars program should be accommodated from within the Mars program, and not taken from other NASA programs. Michael D. Griffin became upset with Stern for making major decisions without consulting him, while Stern was frustrated by Griffin's refusal to allow him to cut or delay politically sensitive projects. Griffin favored cutting "less popular parts" of the budget, including basic research, and Stern's refusal to do so led to his resignation. Casting doubt on the theory that Stern resigned due to conflict with former Administrator Griffin is his statement of March 25, 2009 at spacepolitics.com: On November 23, 2008, in an op-ed in The New York Times, Stern criticized NASA's inability to keep its spending under control. Stern said that, during his own time at NASA, "when I articulated this problem... and consistently curtailed cost increases, I found myself eventually admonished and then neutered by still higher ups, precipitating my resignation earlier this year." While complimenting NASA Administrator Michael D. Griffin, Stern suggested that Griffin's decision to again bail out an over-budget mission was motivated by fear "that any move to cancel the Mars mission would be rebuffed by members of Congress protecting local jobs." Since leaving NASA, Stern has made criticisms of the budgetary process and has advocated for revamping its public appeal. Planetary classification Stern has become involved in the debate surrounding the 2006 definition of planet by the IAU. After the IAU's decision was made he was quoted as saying "It's an awful definition; it's sloppy science and it would never pass peer review" and claimed that Earth, Mars, Jupiter and Neptune have not fully cleared their orbital zones and has stated in his capacity as PI of the New Horizons project that "The New Horizons project [...] will not recognize the IAU's planet definition resolution of August 24, 2006." A 2000 paper by Stern and Levison proposed a system of planet classification that included both the concepts of hydrostatic equilibrium and clearing the neighbourhood used in the new definition, with a proposed classification scheme labeling all sub-stellar objects in hydrostatic equilibrium as "planets" and subclassifying them into "überplanets" and "unterplanets" based on a mathematical analysis of the planet's ability to scatter other objects out of its orbit over a long period of time. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune were classified as neighborhood-clearing "überplanets" and Pluto was classified as an "unterplanet". Satellite planets and belt planets Some large satellites are of similar size or larger than the planet Mercury, e.g. Jupiter's Galilean moons and Titan. Stern has argued that location should not matter and only geophysical attributes should be taken into account in the definition of a planet, and proposes the term satellite planet for a planet-sized object orbiting another planet. Likewise planet-sized objects in the asteroid belt or Kuiper belt should also be planets according to Stern. Others have used the neologism planemo'' (planetary-mass object) for the broad concept of "planet" advocated by Stern. Selected bibliography References 1957 births Planetary scientists Pluto's planethood New Horizons Jewish American scientists Jewish engineers St. Mark's School (Texas) alumni Living people Discoverers of trans-Neptunian objects NASA people University of Texas at Austin College of Natural Sciences alumni University of Colorado Boulder alumni Cockrell School of Engineering alumni

3949228

https://en.wikipedia.org/wiki/Kosmos%20670

Kosmos 670

Kosmos 670 ( meaning Cosmos 670) was an unmanned Soyuz 7K-S test. It used a new and unique inclination of 50.6 degree. The experience from these flights were used in the development of the successor program Soyuz spacecraft the Soyuz 7K-ST. Mission parameters Spacecraft: 7K-S Mass: 6700 kg Crew: None Launched: August 6, 1974 Landed: August 8, 1974 23:59 UTC. Perigee: 221 km Apogee: 294 km Inclination: 50.6 deg Duration: 2.99 days See also Cosmos 772 Cosmos 869 References Kosmos 0670 1974 in the Soviet Union Spacecraft launched in 1974 Soyuz uncrewed test flights

3949262

https://en.wikipedia.org/wiki/Altair%20%28spacecraft%29

Altair (spacecraft)

The Altair spacecraft, previously known as the Lunar Surface Access Module or LSAM, was the planned lander spacecraft component of NASA's cancelled Constellation program. Astronauts would have used the spacecraft for landings on the Moon, which was intended to begin around 2019. The Altair spacecraft was planned to be used both for lunar sortie and lunar outpost missions. On February 1, 2010, U.S. President Barack Obama announced a proposal to cancel the Constellation program (except the Orion spacecraft), to be replaced with a re-scoped program, effective with the U.S. 2011 fiscal year budget. Name On December 13, 2007, NASA's Lunar Surface Access Module was retitled "Altair", after the 12th brightest star in the northern hemisphere's night sky, Altair in the constellation Aquila. In Latin, means "eagle", providing a connection to the first crewed lunar landing, Apollo 11's Eagle; the name Altair itself is a latinization of the Arabic , meaning "the eagle," "the bird," or "the flyer." Prior to the announcement of the "Altair" name, reports had suggested other names had been considered by NASA, but Altair won in a vote by the design team over Pegasus. Description NASA developed only conceptual designs for Altair. No Altair spacecraft were built—plans called for a first landing on the Moon in 2018. Like the Apollo Lunar Module (LM), Altair was envisioned as having two stages. The descent stage would have housed the astronauts, life-support equipment, and fuel for the ascent-stage motor and steering rockets. Like the Apollo LM, the Altair's crew cabin was based on that of a cylinder. Initially a horizontal cylinder, like that of the LM (despite the "boxy" appearance on the outside), contemporary blueprints and computer simulations showed the use of a vertical cylinder. Unlike its two-man Apollo ancestor, Altair was designed to carry the entire four-person crew to the surface, while the temporarily unoccupied Orion crew module would have remained in lunar orbit. Altair was intended to be capable of operating away from Earth (in space and on the lunar surface) for up to 210 Earth days. Altair would also be capable of flying uncrewed missions, as had been proposed with LM Truck concept during the Apollo Applications Program. Mission planners would have been able to choose among three distinct mission modes for Altair: Crewed sortie mode Crewed outpost mode (with no airlock) Uncrewed cargo mode, capable of transporting up to 15 metric tons to the lunar surface Altair, like the LM, was planned to have two hatches; one on top for docking and internal transfer between Altair and Orion, and a main hatch for accessing the lunar surface. Unlike the Apollo LM, Altair would have an airlock similar to those on the Space Shuttle and the International Space Station between the cabin and main hatch. The airlock allowed the astronauts to don and doff their spacesuits without tracking potentially hazardous Moon dust into the main cabin and allowed the vehicle to retain its internal pressure. Unlike the Apollo LM, in which the entire cabin was depressurized during extra-vehicular activity, the airlock would allow a crew member with a malfunctioning spacesuit to quickly return to the Altair spacecraft without having to terminate the entire EVA, and allowed the landing party to complete most of their tasks during their 7-day lunar stay. Also, the airlock would remain as part of the Altair's descent stage, allowing NASA to utilize the airlock as a component of the Lunar Outpost. Because the Ares V payload shroud was planned to have a diameter of and height of (including landing gear), the landers were designed to retract so as to fit within the Ares V's payload shroud. The spacecraft would also have included an improved miniature camping-style toilet, similar to the unit now used on the ISS and the Russian Soyuz spacecraft, a food warmer to eliminate the "cold soup" menu used during Apollo missions, a laser-guided distance measurement system (with radar backup), using data acquired by advanced uncrewed lunar orbiting spacecraft, and new "glass cockpit" and Boeing 787-based computer system identical to that on the Orion spacecraft. Engines Altair intended to utilize current cryogenic technologies for the descent stages and hypergolic technologies for the ascent stage. The Apollo LM, as advanced in both computer and engineering technology in its day, used hypergolic fuels in both of its stages, chemicals that combust on contact with each other, requiring no ignition mechanism and allowing an indefinite storage period. Both the cryogenic and hypergolic systems, like that of the Apollo LM, would be force-fed using high-pressure helium, eliminating the need for malfunction-prone pumps utilized in most rocket technology. Mission requirements obliged the vehicle to be able to descend from an equatorial or high-inclination lunar orbit to a polar landing site, along with bringing it and the Orion spacecraft into lunar orbit, as the Orion spacecraft's onboard Aerojet AJ-10 rocket engine and the amount of fuel it carried would have been insufficient to brake the Orion/Altair stack into lunar orbit (also necessary if flown without Orion for cargo-only missions). The new lander would have been powered by a modified RL-10 engine (currently in use on the upper stage of the Delta IV rocket and Centaur upper stage of the Atlas V rocket), burning liquid hydrogen (LH2) and liquid oxygen (LOX) for the descent phase. A single AJ-10 rocket engine, like that on the Orion, was intended to power the ascent stage. Originally, NASA wanted to power the ascent stage using LOX and liquid methane (LCH4) engines, RS-18, as future missions to Mars would require the astronauts to live on the planet. The Sabatier Reactor could be used to convert the carbon dioxide (CO2) found on Mars into methane, using either found or transported hydrogen, a catalyst, and a source of heat. Cost overruns and immature LOX/LCH4 rocket technology forced NASA to stick with cryogenic and hypergolic systems, although later variants of Altair were meant to serve as testbeds for methane rockets and Sabatier reactors after a permanent lunar base was established. On-orbit assembly Because of the spacecraft's size and weight, Altair, and its associated Earth Departure Stage, would have been launched into a low-Earth orbit (LEO) using the super heavy-lift Ares V launch vehicle, followed by a separate launch of an Orion spacecraft lifted by an Ares I. After rendezvous and docking with Altair in LEO, the crew would have then configured the Orion/Altair for the journey to the Moon. Offices and development The development of Altair was managed by the Constellation Lunar Lander Project Office at Johnson Space Center (JSC). JSC worked directly with Apollo astronauts, various industry suppliers and universities to develop the architecture for Altair. In conjunction with early development a mockup or testbed was to have been developed at JSC to study/develop specialized subsystems and other design considerations. Northrop Grumman, which built the Apollo Lunar Module, was contracted to help the project office develop the system concept. In popular culture In For All Mankind, a 2019 TV series depicting an alternate reality in which the Soviet Union was the first country to successfully land a man on the Moon, NASA develops the LSAM as a successor to the LM after establishing a permanent base on the Moon in the early 1970s. However, the LSAM looks more like the LM than the Altair. See also List of crewed lunar lander designs References External links Altair Lunar Lander Fact Sheet Space Review Globalsecurity Propulsion and Cryogenic Advanced Development for Altair Cancelled American spacecraft Constellation program Crewed spacecraft

3949416

https://en.wikipedia.org/wiki/Kosmos%20772

Kosmos 772

Kosmos 772 ( meaning Cosmos 772) was an uncrewed military Soyuz 7K-S test. It was an unsuccessful mission as only one transmitter worked. Only the 166 MHz frequency transmitter operated, all of the other normal Soyuz wavelengths transmitters failed. The experience from these flights were used in the development of the successor program Soyuz spacecraft the Soyuz 7K-ST. Mission parameters Spacecraft: Soyuz 7K-S Mass: 6750 kg Crew: None Launched: September 29, 1975 Landed: October 3, 1975 4:10 UTC Perigee: 154 km Apogee: 245 km Inclination: 51.8 deg Duration: 3.99 days Maneuver Summary 193 km X 270 km orbit to 195 km X 300 km orbit. Delta V: 8 m/s. 196 km X 300 km orbit to 196 km X 328 km orbit. Delta V: 8 m/s. Total Delta V: 16 m/s. See also Soyuz 7K-OK Soyuz TM-25 Cosmos 670 Cosmos 869 References Kosmos 0772 Kosmos 0772 Kosmos 0772 1975 in the Soviet Union Spacecraft launched in 1975

3949483

https://en.wikipedia.org/wiki/Kosmos%20869

Kosmos 869

Kosmos 869 ( meaning Cosmos 869) was an uncrewed military Soyuz 7K-S test. It was a somewhat successful mission. This was the third and final test flight of a new Soyuz spacecraft type 7K-S. It was designed to be a spaceship for military solo missions. At the time of the launch the program had already been discontinued. The completed spaceships were launched as uncrewed test flights: Kosmos 670, Kosmos 772 and Kosmos 869. The experience from these flights were used in the development of the successor program Soyuz spacecraft the Soyuz 7K-ST. Mission parameters Spacecraft: Soyuz 7K-S. Mass: 6800 kg. Crew: None. Launched: November 29, 1976. Landed: December 17, 1976 10:31 UTC. Perigee: 209 km. Apogee: 289 km. Inclination: 51.7 deg. Duration: 17.99 days. Maneuver Summary 196 km X 290 km orbit to 187 km X 335 km orbit. Delta V: 15 m/s. 187 km X 335 km orbit to 259 km X 335 km orbit. Delta V: 21 m/s. 259 km X 335 km orbit to 260 km X 345 km orbit. Delta V: 2 m/s. 260 km X 345 km orbit to 265 km X 368 km orbit. Delta V: 7 m/s. 265 km X 368 km orbit to 267 km X 391 km orbit. Delta V: 6 m/s. 267 km X 391 km orbit to 300 km X 310 km orbit. Delta V: 32 m/s. Total Delta V: 83 m/s. See also Soyuz 7K-OK Soyuz TM-25 Cosmos 670 Cosmos 772 References Kosmos 0869 Kosmos 0869 Kosmos 0869 1976 in the Soviet Union Spacecraft launched in 1976 1976 in spaceflight

3951115

https://en.wikipedia.org/wiki/88P/Howell

88P/Howell

88P/Howell is a periodic comet with a 5.5 year orbital period. It was discovered on 29 August 1981, by Ellen Howell. In 1975 the comet's perihelion (closest approach to the Sun) was 1.9 AU, but a close approach to Jupiter in 1978 perturbed the perihelion distance closer to the Sun. During the 2009 apparition the comet became as bright as apparent magnitude 8. It last came to perihelion on 6 April 2015; the next perihelion will be on 26 September 2020. On 14 September 2031 the comet will pass from Mars. Between 2000–2050 the closest the comet will come to Earth is in June 2042. In response to New Frontiers program call for Mission 4, a team from Johns Hopkins University Applied Physics Laboratory (JHUAPL) submitted a mission concept proposal called Comet Rendezvous, Sample Acquisition, Investigation, and Return (CORSAIR) that would perform a sample return from comet 88P/Howell. During the 2020 apparition the comet has brightened to about apparent magnitude 10.7 and should reach magnitude 9. References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 88P at Kronk's Cometography 88P at CometBase database Periodic comets 0088 20150406 Comets in 2020 19810829

3951355

https://en.wikipedia.org/wiki/91P/Russell

91P/Russell

91P/Russell, also known as Russell 3, is a periodic comet in the Solar System. It was discovered by Kenneth S. Russell in 1983. References External links Orbital simulation from JPL (Java) / Horizons Ephemeris 91P/Russell 3 – Seiichi Yoshida @ aerith.net 91P at Kronk's Cometography Periodic comets 0091 091P Comets in 2013 19830614

3951393

https://en.wikipedia.org/wiki/98P/Takamizawa

98P/Takamizawa

98P/Takamizawa is a periodic comet in the Solar System. On 29 June 2188 the comet will pass about from Earth. References External links 98P/Takamizawa – Seiichi Yoshida @ aerith.net 98P at Kronk's Cometography Periodic comets 0098 Comets in 2013 19840730

3951466

https://en.wikipedia.org/wiki/99P/Kowal

99P/Kowal

99P/Kowal, also known as Kowal 1, is a periodic comet in the Solar System that orbits out by Jupiter and has a 15 year orbital period. It has been observed regularly since 2019. It came to perihelion in April 2022 and will again in May 2037. References 99P at Gary W. Kronk's Cometography External links 99P/Kowal 1 – Seiichi Yoshida @ aerith.net Periodic comets 0099 Discoveries by Charles T. Kowal 19770424

3953565

https://en.wikipedia.org/wiki/Piszk%C3%A9stet%C5%91%20Station

Piszkéstető Station

The Piszkéstető Station or Piszkéstető Mountain Station is an astronomical observatory in Mátraszentimre in Mátra Mountains, about northeast of Hungary's capital Budapest. It is a station of Konkoly Observatory, first built in 1958. It has the observatory code 461 and 561 for being used by the Szeged University and Konkoly Observatory, respectively. Instruments The observatory features four telescopes: 60/90/180-centimetre Schmidt telescope since 1962 50-centimetre Cassegrain telescope since 1966 1-metre Ritchey–Chrétien telescope since 1974 40-centimetre Ritchey–Chrétien telescope since 2010 Discovery of 2022 EB5 Piszkéstető Station discovered asteroid , which later impacted earth. It is only the fifth asteroid in history to have been discovered prior to impact. This puts the station in a very short list of observatories that have achieved this feat. Several asteroids impact earth every year with enough force to be detected by infrasound sensors designed to detect detonation of nuclear devices, but the vast majority of impacts are unpredicted and occur without warning. Piszkéstető Station discovered this asteroid before it impacted. Honors The minor planet 37432 Piszkéstető was named after the station, where it was discovered by astronomers Krisztián Sárneczky and Zsuzsanna Heiner in January 2002. List of discovered minor planets A total of 19 minor planet discoveries are credited directly to the Piszkéstető Station by the Minor Planet Center. Gallery See also List of asteroid-discovering observatories List of astronomical observatories List of observatory codes References External links Piszkéstető Station 3D animation: 1 m RCC telescope Astronomical observatories in Hungary Minor-planet discovering observatories

3953598

https://en.wikipedia.org/wiki/Mount%20Lemmon%20Survey

Mount Lemmon Survey

Mount Lemmon Survey (MLS) is a part of the Catalina Sky Survey with observatory code G96. MLS uses a cassegrain reflector telescope (with 10560x10560-pixel camera at the f/1.6 prime focus, for a five square degree field of view) operated by the Steward Observatory at Mount Lemmon Observatory, which is located at in the Santa Catalina Mountains northeast of Tucson, Arizona. It is currently one of the most prolific surveys worldwide, especially for discovering near-Earth objects. MLS ranks among the top discoverers on the Minor Planet Center's discovery chart with a total of more than 50,000 numbered minor planets. History Andrea Boattini and the survey accidentally rediscovered 206P/Barnard-Boattini, a lost comet, on 7 October 2008. The comet has made 20 revolutions since 1892 and passed within 0.3–0.4 AU of Jupiter in 1922, 1934 and 2005. This comet was also the first comet to be discovered by photographic means, by the American astronomer Edward Emerson Barnard, who did so on the night of 13 October 1892. On 12 January 2008, Mount Lemmon Survey discovered the near-Earth asteroid at an apparent magnitude of 21 using a reflecting telescope. was discovered by the Mount Lemmon Survey on 27 September 2009 and it is a stable Mars trojan asteroid. The survey also discovered the unusual Aten asteroid , a dynamically cold Kozai resonator, on 31 March 2012. See also List of astronomical observatories Mount Lemmon 2017 XX61 References External links NEODyS Astronomical surveys Discoverers of comets Astronomical observatories in Arizona

3954327

https://en.wikipedia.org/wiki/Maritime%20territory

Maritime territory

Maritime territory is a term used in international law to denote coastal waters which are not Territorial Waters though in immediate contact with the sea. In the case of Territorial Waters, the dominion of the adjacent state is subject to a limitation. Dominion over maritime territory is not subject to any limitation. Thus any strait through which the right of passage of foreign vessels can be forbidden, or bays so land-locked that they cannot be held to form part of any ocean-highway, are maritime territory. See also International waters Territorial waters References Law of the sea

3954482

https://en.wikipedia.org/wiki/Comet%20IRAS%E2%80%93Araki%E2%80%93Alcock

Comet IRAS–Araki–Alcock

Comet IRAS–Araki–Alcock (formal designation C/1983 H1, formerly 1983 VII) is a long-period comet that, in 1983, made the closest known approach to Earth of any comet in 200 years, at a distance of about . The comet was named after its discoverers the Infrared Astronomical Satellite and two amateur astronomers, George Alcock of the United Kingdom and Genichi Araki of Japan. Both men were schoolteachers by profession, although Alcock was retired. Alcock had made his discovery simply by observing through the window of his home, using binoculars. During the closest approach, the comet appeared as a circular cloud about the size of the full moon, having no discernible tail, and shining at a naked eye magnitude of 3–4. It swept across the sky at an angular speed of about 30 degrees per day. On May 11 the comet was detected on radar by Arecibo Observatory and Goldstone Solar System Radar making it the first comet detected by two different radar systems. A second detection was made by Goldstone on 14 May. It is a long-period comet, with an orbital period of about 970 years, and is the parent comet of the minor Eta Lyrid meteor shower. This shower's radiant lies between Vega and Cygnus and produces 1 or 2 meteors an hour in mid-May with a peak between 9 May and 11 May. Flyby comparison Comet IRAS–Araki–Alcock made its closest approach to Earth in 1983, at a distance of about . It was the closest approach up to that time of any comet in 200 years; only Lexell's Comet, in 1770, and 55P/Tempel-Tuttle, in 1366, are thought to have come closer. Subsequently, on 12 June 1999, the small comet P/1999 J6 (SOHO) passed about from Earth. What was thought to be a small fragment of 252P/LINEAR, called P/2016 BA14, passed at a distance of on 22 March 2016. 1983 Flyby References Near-Earth comets Long-period comets Discoveries by IRAS IRAS catalogue objects Astronomical objects discovered in 1983 Meteor shower progenitors

3957313

https://en.wikipedia.org/wiki/Hallmark%20holiday

Hallmark holiday

In the United States, a Hallmark holiday is a holiday that is perceived to exist primarily for commercial purposes, rather than to commemorate a traditionally or historically significant event. Background The name comes from Hallmark Cards, a privately owned American company, that benefits from such manufactured events through sales of greeting cards and other items. Holidays that have been referred to as "Hallmark holidays" Valentine's Day Mother's Day Father's Day Grandparents Day National Son's Day National Daughter's Day Sweetest Day Boss's Day Administrative Professionals' Day Teacher Appreciation Day, Clergy Appreciation Day See also Anna Jarvis and Mother's Day Christmas in July in the Northern Hemisphere Valentine's Day List of food days References Further reading Greeting cards Hallmark Cards Holidays Pejorative terms

3964619

https://en.wikipedia.org/wiki/Fog%20bow

Fog bow

A fog bow, sometimes called a white rainbow, is a similar phenomenon to a rainbow; however, as its name suggests, it appears as a bow in fog rather than rain. Because of the very small size of water droplets that cause fog—smaller than —the fog bow has only very weak colors, with a red outer edge and bluish inner edge. The colors fade due to being smeared out by the diffraction effect of the smaller droplets. In many cases, when the droplets are very small, fog bows appear white, and are therefore sometimes called white rainbows. Along with its larger angular size, this lack of color is a feature of a fog bow that distinguishes it from a glory, which has multiple pale-colored rings caused by diffraction. When droplets forming it are almost all of the same size, the fog bow can have multiple inner rings, or supernumeraries, which are more strongly colored than the main bow. A fog bow seen in clouds, typically from an aircraft looking downwards, is called a cloud bow. Mariners sometimes call fog bows sea-dogs. Direction A fog bow is seen in the same direction as a rainbow, thus the sun would be behind the head of the observer and the direction of view would be into a bank of fog (which may not be noticeable in directions away from the bow itself). Its outer radius is slightly less than that of a rainbow. When a fog bow appears at night it is called a lunar fog bow. See also Circumhorizontal arc Circumzenithal arc Cloud iridescence Dewbow Halo Moonbow Sun dog References External links Photos and explanation of fogbows at Atmospheric Optics. Fogbow image gallery at AKM website. Fogbows at Glows, Bows and Haloes site. Atmospheric optical phenomena Atmospheric sciences Earth phenomena Rainbow

3966381

https://en.wikipedia.org/wiki/Turbopause

Turbopause

The turbopause, also called the homopause, marks the altitude in an atmosphere below which turbulent mixing dominates. Mathematically, it is defined as the point where the coefficient of Eddy diffusion is equal to the coefficient of molecular diffusion. The region below the turbopause is known as the homosphere, where the atmosphere is well mixed for chemical species which have long mean residence times. Highly reactive chemicals tend to have variable concentration throughout the atmosphere, while unreactive species have more homogeneous concentrations. The region above the turbopause is the heterosphere, where molecular diffusion dominates and the chemical composition of the atmosphere varies according to chemical species and their atomic weight. Earth's turbopause lies near the mesopause, at the intersection of the mesosphere and the thermosphere, at an altitude of roughly . Some other turbopauses in the Solar System that are known include Venus' turbopause at about , Mars' at about , Jupiter's at roughly , and Titan's at around . It was discovered by French scientists following the firing of two Véronique sounding rockets on 10 and 12 March 1959. References Specific Atmospheric boundaries Atmosphere of Earth

3966984

https://en.wikipedia.org/wiki/River%20engineering

River engineering

River engineering is a discipline of civil engineering which studies human intervention in the course, characteristics, or flow of a river with the intention of producing some defined benefit. People have intervened in the natural course and behaviour of rivers since before recorded history—to manage the water resources, to protect against flooding, or to make passage along or across rivers easier. Since the Yuan Dynasty and Ancient Roman times, rivers have been used as a source of hydropower. From the late 20th century, the practice of river engineering has responded to environmental concerns broader than immediate human benefit. Some river engineering projects have focused exclusively on the restoration or protection of natural characteristics and habitats. Hydromodification encompasses the systematic response to alterations to riverine and non-riverine water bodies such as coastal waters (estuaries and bays) and lakes. The U.S. Environmental Protection Agency (EPA) has defined hydromodification as the "alteration of the hydrologic characteristics of coastal and non-coastal waters, which in turn could cause degradation of water resources." River engineering has often resulted in unintended systematic responses, such as reduced habitat for fish and wildlife, and alterations of water temperature and sediment transport patterns. Beginning in the late 20th century, the river engineering discipline has been more focused on repairing hydromodified degradations and accounting for potential systematic response to planned alterations by considering fluvial geomorphology. Fluvial geomorphology is the study of how rivers change their form over time. Fluvial geomorphology is the cumulation of a number of sciences including open channel hydraulics, sediment transport, hydrology, physical geology, and riparian ecology. River engineering practitioners attempt to understand fluvial geomorphology, implement a physical alteration, and maintain public safety. Characteristics of rivers The size of rivers above any tidal limit and their average freshwater discharge are proportionate to the extent of their basins and the amount of rain which, after falling over these basins, reaches the river channels in the bottom of the valleys, by which it is conveyed to the sea. The basin of a river is the expanse of country bounded by a watershed (called a "divide" in North America) over which rainfall flows down towards the river traversing the lowest part of the valley, whereas the rain falling on the far slope of the watershed flows away to another river draining an adjacent basin. River basins vary in extent according to the configuration of the country, ranging from the insignificant drainage areas of streams rising on high ground very near the coast and flowing straight down into the sea, up to immense tracts of great continents, where rivers rising on the slopes of mountain ranges far inland have to traverse vast stretches of valleys and plains before reaching the ocean. The size of the largest river basin of any country depends on the extent of the continent in which it is situated, its position in relation to the hilly regions in which rivers generally arise and the sea into which they flow, and the distance between the source and the outlet into the sea of the river draining it. The rate of flow of rivers depends mainly upon their fall, also known as the gradient or slope. When two rivers of different sizes have the same fall, the larger river has the quicker flow, as its retardation by friction against its bed and banks is less in proportion to its volume than is the case with the smaller river. The fall available in a section of a river approximately corresponds to the slope of the country it traverses; as rivers rise close to the highest part of their basins, generally in hilly regions, their fall is rapid near their source and gradually diminishes, with occasional irregularities, until, in traversing plains along the latter part of their course, their fall usually becomes quite gentle. Accordingly, in large basins, rivers in most cases begin as torrents with a very variable flow, and end as gently flowing rivers with a comparatively regular discharge. The irregular flow of rivers throughout their course forms one of the main difficulties in devising works for mitigating inundations or for increasing the navigable capabilities of rivers. In tropical countries subject to periodical rains, the rivers are in flood during the rainy season and have hardly any flow during the rest of the year, while in temperate regions, where the rainfall is more evenly distributed throughout the year, evaporation causes the available rainfall to be much less in hot summer weather than in the winter months, so that the rivers fall to their low stage in the summer and are very liable to be in flood in the winter. In fact, with a temperate climate, the year may be divided into a warm and a cold season, extending from May to October and from November to April in the Northern hemisphere respectively; the rivers are low and moderate floods are of rare occurrence during the warm period, and the rivers are high and subject to occasional heavy floods after a considerable rainfall during the cold period in most years. The only exceptions are rivers which have their sources amongst mountains clad with perpetual snow and are fed by glaciers; their floods occur in the summer from the melting of snow and ice, as exemplified by the Rhône above the Lake of Geneva, and the Arve which joins it below. But even these rivers are liable to have their flow modified by the influx of tributaries subject to different conditions, so that the Rhone below Lyon has a more uniform discharge than most rivers, as the summer floods of the Arve are counteracted to a great extent by the low stage of the Saône flowing into the Rhone at Lyon, which has its floods in the winter when the Arve, on the contrary, is low. Another serious obstacle encountered in river engineering consists in the large quantity of detritus they bring down in flood-time, derived mainly from the disintegration of the surface layers of the hills and slopes in the upper parts of the valleys by glaciers, frost and rain. The power of a current to transport materials varies with its velocity, so that torrents with a rapid fall near the sources of rivers can carry down rocks, boulders and large stones, which are by degrees ground by attrition in their onward course into slate, gravel, sand and silt, simultaneously with the gradual reduction in fall, and, consequently, in the transporting force of the current. Accordingly, under ordinary conditions, most of the materials brought down from the high lands by torrential water courses are carried forward by the main river to the sea, or partially strewn over flat alluvial plains during floods; the size of the materials forming the bed of the river or borne along by the stream is gradually reduced on proceeding seawards, so that in the Po River in Italy, for instance, pebbles and gravel are found for about 140 miles below Turin, sand along the next 100 miles, and silt and mud in the last 110 miles (176 km). Methods Improvements can be divided into those that are aimed at improving the flow of the river, particularly in flood conditions, and those that aim to hold back the flow, primarily for navigation purposes, although power generation is often an important factor. The former is known in the US as channelization and the latter is generally referred to as canalization. Channelization Reducing the length of the channel by substituting straight cuts for a winding course is the only way in which the effective fall can be increased. This involves some loss of capacity in the channel as a whole, and in the case of a large river with a considerable flow it is very difficult to maintain a straight cut owing to the tendency of the current to erode the banks and form again a sinuous channel. Even if the cut is preserved by protecting the banks, it is liable to produce changes shoals and raise the flood-level in the channel just below its termination. Nevertheless, where the available fall is exceptionally small, as in land originally reclaimed from the sea, such as the English Fenlands, and where, in consequence, the drainage is in a great measure artificial, straight channels have been formed for the rivers. Because of the perceived value in protecting these fertile, low-lying lands from inundation, additional straight channels have also been provided for the discharge of rainfall, known as drains in the fens. Even extensive modification of the course of a river combined with an enlargement of its channel often produces only a limited reduction in flood damage. Consequently, such floodworks are only commensurate with the expenditure involved where significant assets (such as a town) are under threat. Additionally, even when successful, such floodworks may simply move the problem further downstream and threaten some other town. Recent floodworks in Europe have included restoration of natural floodplains and winding courses, so that floodwater is held back and released more slowly. The removal of obstructions, natural or artificial (e.g., trunks of trees, boulders and accumulations of gravel) from a river bed furnishes a simple and efficient means of increasing the discharging capacity of its channel. Such removals will consequently lower the height of floods upstream. Every impediment to the flow, in proportion to its extent, raises the level of the river above it so as to produce the additional artificial fall necessary to convey the flow through the restricted channel, thereby reducing the total available fall. Human intervention sometimes inadvertently modifies the course or characteristics of a river, for example by introducing obstructions such as mining refuse, sluice gates for mills, fish-traps, unduly wide piers for bridges and solid weirs. By impeding flow these measures can raise the flood-level upstream. Regulations for the management of rivers may include stringent prohibitions with regard to pollution, requirements for enlarging sluice-ways and the compulsory raising of their gates for the passage of floods, the removal of fish traps, which are frequently blocked up by leaves and floating rubbish, reduction in the number and width of bridge piers when rebuilt, and the substitution of movable weirs for solid weirs. By installing gauges in a fairly large river and its tributaries at suitable points, and keeping continuous records for some time of the heights of the water at the various stations, the rise of the floods in the different tributaries, the periods they take in passing down to definite stations on the main river, and the influence they severally exercise on the height of the floods at these places, can be ascertained. With the help of these records, and by observing the times and heights of the maximum rise of a particular flood at the stations on the various tributaries, the time of arrival and height of the top of the flood at any station on the main river can be predicted with remarkable accuracy two or more days beforehand. By communicating these particulars about a high flood to places on the lower river, weir-keepers are enabled to fully open the movable weirs beforehand to permit the passage of the flood, and riparian inhabitants receive timely warning of the impending inundation. Where portions of a riverside town are situated below the maximum flood-level, or when it is important to protect land adjoining a river from inundations, the overflow of the river must be diverted into a flood-dam or confined within continuous embankments on both sides. By placing these embankments somewhat back from the margin of the river-bed, a wide flood-channel is provided for the discharge of the river as soon as it overflows its banks, while leaving the natural channel unaltered for the ordinary flow. Low embankments may be sufficient where only exceptional summer floods have to be excluded from meadows. Occasionally the embankments are raised high enough to retain the floods during most years, while provision is made for the escape of the rare, exceptionally high floods at special places in the embankments, where the scour of the issuing current is guarded against, and the inundation of the neighboring land is least injurious. In this manner, the increased cost of embankments raised above the highest flood-level of rare occurrence is avoided, as is the danger of breaches in the banks from an unusually high flood-rise and rapid flow, with their disastrous effects. Effects A most serious objection to the formation of continuous, high embankments along rivers bringing down considerable quantities of detritus, especially near a place where their fall has been abruptly reduced by descending from mountain slopes onto alluvial plains, is the danger of their bed being raised by deposit, producing a rise in the flood-level, and necessitating a raising of the embankments if inundations are to be prevented. Longitudinal sections of the Po River, taken in 1874 and 1901, show that its bed was materially raised during this period from the confluence of the Ticino to below Caranella, despite the clearance of sediment effected by the rush through breaches. Therefore, the completion of the embankments, together with their raising, would only eventually aggravate the injuries of the inundations they have been designed to prevent, as the escape of floods from the raised river must occur sooner or later. In the UK, problems of flooding of domestic properties around the turn of the 21st century have been blamed on inadequate planning controls which have permitted development on floodplains. This exposes the properties on the floodplain to flood, and the substitution of concrete for natural strata speeds the run-off of water, which increases the danger of flooding downstream. In the Midwestern United States and the Southern United States the term for this measure is channelization. Much of it was done under the auspices or overall direction of the United States Army Corps of Engineers. One of the most heavily channelized areas in the United States is West Tennessee, where every major stream with one exception (the Hatchie River) has been partially or completely channelized. Advantages Channelization of a stream may be undertaken for several reasons. One is to make a stream more suitable for navigation or for navigation by larger vessels with deep draughts. Another is to restrict water to a certain area of a stream's natural bottom lands so that the bulk of such lands can be made available for agriculture. A third reason is flood control, with the idea of giving a stream a sufficiently large and deep channel so that flooding beyond those limits will be minimal or nonexistent, at least on a routine basis. One major reason is to reduce natural erosion; as a natural waterway curves back and forth, it usually deposits sand and gravel on the inside of the corners where the water flows slowly, and cuts sand, gravel, subsoil, and precious topsoil from the outside corners where it flows rapidly due to a change in direction. Unlike sand and gravel, the topsoil that is eroded does not get deposited on the inside of the next corner of the river. It simply washes away. Disadvantages Channelization has several predictable and negative effects. One of them is loss of wetlands. Wetlands are an excellent habitat for many forms of wildlife, and additionally serve as a "filter" for much of the world's surface fresh water. Another is the fact that channelized streams are almost invariably straightened. For example, the channelization of Florida's Kissimmee River has been cited as a cause contributing to the loss of wetlands. This straightening causes the streams to flow more rapidly, which can, in some instances, vastly increase soil erosion. It can also increase flooding downstream from the channelized area, as larger volumes of water traveling more rapidly than normal can reach choke points over a shorter period of time than they otherwise would, with a net effect of flood control in one area coming at the expense of greatly aggravated flooding in another. In addition, studies have shown that stream channelization results in declines of river fish populations. A 1971 study of the Chariton River in northern Missouri, United States, found that the channelized section of the river contained only 13 species of fish, whereas the natural segment of the stream was home to 21 species of fish. The biomass of fish able to be caught in the dredged segments of the river was 80 percent less than in the natural parts of the same stream. This loss of fish diversity and abundance is thought to occur because of reduction in habitat, elimination of riffles and pools, greater fluctuation of stream levels and water temperature, and shifting substrates. The rate of recovery for a stream once it has been dredged is extremely slow, with many streams showing no significant recovery 30 to 40 years after the date of channelization. Modern policy in the United States For the reasons cited above, in recent years stream channelization has been greatly curtailed in the U.S., and in some instances even partially reversed. In 1990 the United States Government published a "no net loss of wetlands" policy, whereby a stream channelization project in one place must be offset by the creation of new wetlands in another, a process known as "mitigation." The major agency involved in the enforcement of this policy is the same Army Corps of Engineers, which for many years was the primary promoter of wide-scale channelization. Often, in the instances where channelization is permitted, boulders may be installed in the bed of the new channel so that water velocity is slowed, and channels may be deliberately curved as well. In 1990 the U.S. Congress gave the Army Corps a specific mandate to include environmental protection in its mission, and in 1996 it authorized the Corps to undertake restoration projects. The U.S. Clean Water Act regulates certain aspects of channelization by requiring non-Federal entities (i.e. state and local governments, private parties) to obtain permits for dredging and filling operations. Permits are issued by the Army Corps with EPA participation. Canalization of rivers Rivers whose discharge is liable to become quite small at their low stage, or which have a somewhat large fall, as is usual in the upper part of rivers, cannot be given an adequate depth for navigation purely by works which regulate the flow; their ordinary summer level has to be raised by impounding the flow with weirs at intervals across the channel, while a lock has to be provided alongside the weir, or in a side channel, to provide for the passage of vessels. A river is thereby converted into a succession of fairly level reaches rising in steps up-stream, providing still-water navigation comparable to a canal; but it differs from a canal in the introduction of weirs for keeping up the water-level, in the provision for the regular discharge of the river at the weirs, and in the two sills of the locks being laid at the same level instead of the upper sill being raised above the lower one to the extent of the rise at the lock, as usual on canals. Canalization secures a definite available depth for navigation; and the discharge of the river generally is amply sufficient for maintaining the impounded water level, as well as providing the necessary water for locking. Navigation, however, is liable to be stopped during the descent of high floods, which in many cases rise above the locks; and it is necessarily arrested in cold climates on all rivers by long, severe frosts, and especially by ice. Many small rivers, like the Thames above its tidal limit, have been rendered navigable by canalization, and several fairly large rivers have thereby provided a good depth for vessels for considerable distances inland. Thus the canalized Seine has secured a navigable depth of 10 feet (3.2 metres) from its tidal limit up to Paris, a distance of 135 miles, and a depth of 6 feet (2.06 metres) up to Montereau, 62 miles higher up. Regulation works (flow and depth control) As rivers flow onward towards the sea, they experience a considerable diminution in their fall, and a progressive increase in the basin which they drain, owing to the successive influx of their various tributaries. Thus, their current gradually becomes more gentle and their discharge larger in volume and less subject to abrupt variations; and, consequently, they become more suitable for navigation. Eventually, large rivers, under favorable conditions, often furnish important natural highways for inland navigation in the lower portion of their course, as, for instance, the Rhine, the Danube and the Mississippi. River engineering works are only required to prevent changes in the course of the stream, to regulate its depth, and especially to fix the low-water channel and concentrate the flow in it, so as to increase as far as practicable the navigable depth at the lowest stage of the water level. Engineering works to increase the navigability of rivers can only be advantageously undertaken in large rivers with a moderate fall and a fair discharge at their lowest stage, for with a large fall the current presents a great impediment to up-stream navigation, and there are generally great variations in water level, and when the discharge becomes very small in the dry season. It is impossible to maintain a sufficient depth of water in the low-water channel. The possibility to secure uniformity of depth in a river by lowering the shoals obstructing the channel depends on the nature of the shoals. A soft shoal in the bed of a river is due to deposit from a diminution in velocity of flow, produced by a reduction in fall and by a widening of the channel, or to a loss in concentration of the scour of the main current in passing over from one concave bank to the next on the opposite side. The lowering of such a shoal by dredging merely effects a temporary deepening, for it soon forms again from the causes which produced it. The removal, moreover, of the rocky obstructions at rapids, though increasing the depth and equalizing the flow at these places, produces a lowering of the river above the rapids by facilitating the efflux, which may result in the appearance of fresh shoals at the low stage of the river. Where, however, narrow rocky reefs or other hard shoals stretch across the bottom of a river and present obstacles to the erosion by the current of the soft materials forming the bed of the river above and below, their removal may result in permanent improvement by enabling the river to deepen its bed by natural scour. The capability of a river to provide a waterway for navigation during the summer or throughout the dry season depends on the depth that can be secured in the channel at the lowest stage. The problem in the dry season is the small discharge and deficiency in scour during this period. A typical solution is to restrict the width of the low-water channel, concentrate all of the flow in it, and also to fix its position so that it is scoured out every year by the floods which follow the deepest part of the bed along the line of the strongest current. This can be effected by closing subsidiary low-water channels with dikes across them, and narrowing the channel at the low stage by low-dipping cross dikes extending from the river banks down the slope and pointing slightly up-stream so as to direct the water flowing over them into a central channel. Estuarine works The needs of navigation may also require that a stable, continuous, navigable channel is prolonged from the navigable river to deep water at the mouth of the estuary. The interaction of river flow and tide needs to be modeled by computer or using scale models, moulded to the configuration of the estuary under consideration and reproducing in miniature the tidal ebb and flow and fresh-water discharge over a bed of very fine sand, in which various lines of training walls can be successively inserted. The models should be capable of furnishing valuable indications of the respective effects and comparative merits of the different schemes proposed for works. See also Bridge scour Flood control References External links U.S. Army Corps of Engineers – Civil Works Program Environmental engineering Riparian zone Rivers River regulation Hydrology and urban planning Water resources management

3969036

https://en.wikipedia.org/wiki/Coat%20of%20arms%20of%20Saint%20Helena

Coat of arms of Saint Helena

The coat of arms of Saint Helena, part of the British Overseas Territory of Saint Helena, Ascension and Tristan da Cunha, was authorised on 30 January 1984. The arms feature a shield, with the top third showing the national bird, the Saint Helena plover (Charadrius sanctaehelenae), known locally as the wirebird – stylized, but with its unmistakable head pattern. The bottom two thirds depict a coastal scene of the island, a three-masted sailing ship with the mountainous island to the left. The coastal scene is taken from the colonial seal of the colony and shows the flag of England flying from the ship (when the shield was first introduced in 1874 the flag was a White Ensign). The motto is Loyal and unshakable. The full coat of arms features, above the shield, a woman holding a cross and a flower. This represents Helena of Constantinople, also known as Saint Helena, after whom the island is named. The cross is shown as Helena is credited with finding the relics of the True Cross (cross upon which Jesus was crucified). The shield of the arms features on the flag of Saint Helena and the Governor's flag. The local two pound coin has the full coat of arms on its reverse. Arms usage by dependencies The arms were also used by Ascension Island and Tristan da Cunha when they were dependencies of Saint Helena before 2009. Tristan da Cunha was granted its own arms in 2002 and Ascension Island was granted its own arms in 2012. See also Coat of arms of Saint Helena, Ascension and Tristan da Cunha Coat of arms of Ascension Island Coat of arms of Tristan da Cunha List of coats of arms of the United Kingdom and dependencies References Saint Helena Saint Helena Saint Helena Saint Helenian culture Saint Helena Saint Helena Saint Helena Saint Helena Helena, mother of Constantine I

3972465

https://en.wikipedia.org/wiki/Sound%20Dues

Sound Dues

The Sound Dues (or Sound Tolls; ) were a toll on the use of the Øresund, or "Sound" strait separating the modern day borders of Denmark and Sweden. The tolls constituted up to two thirds of Denmark's state income in the 16th and 17th centuries. The dues were introduced by King Eric of Pomerania in 1429 and remained in effect until the Copenhagen Convention of 1857 (with the sole exception of Swedish ships between 1660 and 1712). Tolls in the Great Belt had been collected by the Danish Crown at least a century prior to the establishment of the dues by Eric of Pomerania. History All foreign ships passing through the strait, whether en route to or from Denmark or not, had to stop in Helsingør and pay a toll to the Danish Crown. If a ship refused to stop, cannons in both Helsingør and Helsingborg could open fire and sink it. In 1567, the toll was changed into a 1–2% tax on the cargo value, providing three times more revenue. To keep the captains from understating the value of the cargo on which the tax was computed, the right to purchase the cargo at the stated value was reserved. In order to avoid ships simply taking a different route, tolls were also collected at the two other Danish straits, the Great Belt and the Little Belt; sometimes non-Danish vessels were forbidden to use any other waterways but the Øresund, and transgressing vessels were confiscated or sunk. The Sound Dues remained the most important source of income for the Danish Crown for several centuries, thus making Danish kings relatively independent of Denmark's Privy Council and aristocracy. However, the dues were an irritant to nations engaged in trade in the Baltic Sea, especially Sweden. Sweden had initially been exempted from the dues at the time of their introduction because it was then in the Kalmar Union along with Denmark. However, after the Kalmar War and the Treaty of Knäred in 1613 Denmark-Norway introduced dues on cargoes from Sweden's Baltic possessions and on non-Swedish ships carrying Swedish cargo. The friction over the Dues was an official casus belli (reason for war) of the Torstenson War in 1643. In 1658, Denmark-Norway had to cede her provinces east of the sound (Scania, Halland, Blekinge, Bohuslän, and the island of Ven) to Sweden as a consequence of the Second Northern War. Thus, the toll could not be enforced as well as before but Denmark-Norway retained its established right of the dues. Swedish shipping became exempt from the Sound Dues by the terms of the Treaty of Copenhagen, signed on 27 May 1660. The exemption was withdrawn after Sweden's defeat in the Great Northern War and the Treaty of Frederiksborg of 1720, although the eastern shore of the Sound was now Swedish. Copenhagen Convention The Copenhagen Convention, which came into force on 14 March 1857, abolished the dues and all Danish straits were made international waterways free to all commercial shipping. See also Skibsklarerergaarden Sound Toll Registers Online (STR) : http://dietrich.soundtoll.nl/public/ References Literature Degn, Ole. Tolden i Sundet: Toldopkrævning, politik og skibsfart i Øresund 1429-1857. København: Told- og Skattehistorisk Selskab, 2010. . Degn, Ole (Editor). The Sound Toll at Elsinore: Politics, Shipping and the Collection of Duties 1429-1857. Copenhagen: Museum Tusculanum Press and The Danish Society for Customs and Tax History, 2017. . Economic history of Denmark Toll (fee) 1429 establishments in Europe 1420s establishments in Denmark 15th century in Skåne County 1857 disestablishments in Europe Law of the sea Øresund

3973438

https://en.wikipedia.org/wiki/High-altitude%20nuclear%20explosion

High-altitude nuclear explosion

High-altitude nuclear explosions are the result of nuclear weapons testing within the upper layers of the Earth's atmosphere and in outer space. Several such tests were performed at high altitudes by the United States and the Soviet Union between 1958 and 1962. The Partial Test Ban Treaty was passed in October 1963, ending atmospheric and exoatmospheric nuclear tests. The Outer Space Treaty of 1967 banned the stationing of nuclear weapons in space, in addition to other weapons of mass destruction. The Comprehensive Nuclear-Test-Ban Treaty of 1996 prohibits all nuclear testing; whether over- or underground, underwater or in the atmosphere. EMP generation The strong electromagnetic pulse (EMP) that results has several components. In the first few tenths of nanoseconds, about a tenth of a percent of the weapon yield appears as powerful gamma rays with energies of one to three mega-electron volts (MeV, a unit of energy). The gamma rays penetrate the atmosphere and collide with air molecules, depositing their energy to produce huge quantities of positive ions and recoil electrons (also known as Compton electrons). These collisions create MeV-energy Compton electrons that then accelerate and spiral along the Earth's magnetic field lines. The resulting transient electric fields and currents that arise generate electromagnetic emissions in the radio frequency range of to . This high-altitude EMP occurs between above the Earth's surface. The potential as an anti-satellite weapon became apparent in August 1958 during Hardtack Teak. The EMP observed at the Apia Observatory at Samoa was four times more powerful than any created by solar storms, while in July 1962 the Starfish Prime test, damaged electronics in Honolulu and New Zealand (approximately away), fused 300 street lights on Oahu (Hawaii), set off about 100 burglar alarms, and caused the failure of a microwave repeating station on Kauai, which cut off the sturdy telephone system from the other Hawaiian islands. The radius for an effective satellite kill for the various Compton radiation produced by such a nuclear weapon in space was determined to be roughly . Further testing to this end was carried out, and embodied in a Department of Defense program, Program 437. Drawbacks There are problems with nuclear weapons carried over to testing and deployment scenarios, however. Because of the very large radius associated with nuclear events, it was nearly impossible to prevent indiscriminate damage to other satellites, including one's own satellites. Starfish Prime produced an artificial radiation belt in space that soon destroyed three satellites (Ariel, TRAAC, and Transit 4B all failed after traversing the radiation belt, while Cosmos V, Injun I and Telstar 1 suffered minor degradation, due to some radiation damage to solar cells, etc.). The radiation dose rate was at least 0.6 Gy/day at four months after Starfish for a well-shielded satellite or crewed capsule in a polar circular earth orbit, which caused NASA concern with regard to its crewed space exploration programs. Differences from atmospheric tests In general, nuclear effects in space (or very high altitudes) have a qualitatively different display. While an atmospheric nuclear explosion has a characteristic mushroom-shaped cloud, high-altitude and space explosions tend to manifest a spherical 'cloud,' reminiscent of other space-based explosions until distorted by Earth's magnetic field, and the charged particles resulting from the blast can cross hemispheres to create an auroral display which has led documentary maker Peter Kuran to characterize these detonations as 'the rainbow bombs'. The visual effects of a high-altitude or space-based explosion may last longer than atmospheric tests, sometimes in excess of 30 minutes. Heat from the Bluegill Triple Prime shot, at an altitude of , was felt by personnel on the ground at Johnston Atoll, and this test caused retina burns to two personnel at ground zero who were not wearing their safety goggles. Soviet high-altitude tests The Soviets detonated four high-altitude tests in 1961 and three in 1962. During the Cuban Missile Crisis in October 1962, both the US and the USSR detonated several high-altitude nuclear explosions as a form of saber rattling. The worst effects of a Soviet high-altitude test occurred on 22 October 1962, in the Soviet Project K nuclear tests (ABM System A proof tests) when a 300 kt missile-warhead detonated near Dzhezkazgan at altitude. The EMP fused of overhead telephone line with a measured current of , started a fire that burned down the Karaganda power plant, and shut down of shallow-buried power cables between Tselinograd and Alma-Ata. List of high-altitude nuclear explosions See also Nuclear weapons testing Nuclear electromagnetic pulse Operation Argus Operation Fishbowl Outer Space Treaty Partial Test Ban Treaty Project Highwater Soviet Project K nuclear tests The Yekaterinburg Fireball is suspected by some of being a high altitude nuclear explosion References External links "High-altitude nuclear explosions" Peter Kuran's Nukes in Space: The Rainbow Bombs – documentary film from 1999 United States high-altitude test experiences – A Review Emphasizing the Impact on the Environment Measured EMP waveform data and actual effects from high-altitude nuclear weapons tests by America and Russia American and British official analyses of photography from high-altitude nuclear explosions US Government Films: Operation Argus Operation Dominic Starfish Prime Operation Fishbowl Operation Dominic – Christmas Island Operation Dominic – Johnston Island High-Altitude Effects – Phenomenology High-Altitude Effects – Systems Interference Nuclear weapons testing Energy weapons

3975265

https://en.wikipedia.org/wiki/Nordic%20aliens

Nordic aliens

In ufology, Nordic alien is the name given to alleged humanoid extraterrestrials, purported to come from the Pleiades, who resemble Nordic-Scandinavians. Alleged contactees describe them as being six to seven feet tall (about two meters) with long blond hair, blue eyes, and fair skin. George Adamski is credited with being among the first to claim contact with Nordic aliens in the mid 1950s, and scholars note that the mythology of extraterrestrial visitation from beings with features described as "Aryan" often include claims of telepathy, benevolence, and physical beauty. History Cultural historian David J. Skal wrote that early stories of Nordic-type aliens may have been partially inspired by the 1951 film The Day the Earth Stood Still, in which an extraterrestrial arrives on Earth to warn humanity about the dangers of atomic weapons. Bates College professor Stephanie Kelley-Romano described alien abduction beliefs as "a living myth", and notes that, among believers, Nordic aliens "are often associated with spiritual growth and love and act as protectors for the experiencers." In contactee and ufology literature, Nordic aliens are often described as benevolent or even "magical" beings who want to observe and communicate with humans and are concerned about the Earth's ecology or prospects for world peace. Believers also ascribe telepathic powers to Nordic aliens, and describe them as "paternal, watchful, smiling, affectionate, and youthful." During the 1950s, many people alleging to be contactees, especially those in Europe, claimed encounters with beings fitting this description. Such claims became relatively less common in subsequent decades, as the grey alien supplanted the Nordic in most alleged accounts of extraterrestrial encounters. Publications by those claiming to have been contacted Books claiming personal contact with Nordic aliens include George Adamski's Flying Saucers Have Landed and Inside the Space Ships, Howard Menger's From Outer Space to You, and Travis Walton's The Walton Experience. See also Truman Bethurum Elizabeth Klarer Space Brothers Billy Meier Linda Moulton Howe List of alleged extraterrestrial beings Star people (New Age) Arcturians (New Age) UFOs UFO religion References External links Alleged UFO-related entities Nordicism Taurus (constellation)

3980636

https://en.wikipedia.org/wiki/Meitner%20%28Venusian%20crater%29

Meitner (Venusian crater)

Meitner is a multiring impact crater on Venus. This impact crater was named after the female Austrian-Swedish physicist, Lise Meitner, in her honour. References Impact craters on Venus

3980981

https://en.wikipedia.org/wiki/101P/Chernykh

101P/Chernykh

101P/Chernykh is a periodic comet which was first discovered on August 19, 1977, by Nikolaj Stepanovich Chernykh. It will next come to perihelion (closest approach to the Sun) in 2034. In 1991, 101P/Chernykh was observed to split. JPL concluded that the comet split in April 1991, when 3.3 AU from the Sun. The primary nucleus is in diameter and was last observed in 2022. Fragment B has not been observed since 2006. As of epoch 2022, fragment B takes 21 days longer to orbit the Sun. References External links 101P/Chernykh – Seiichi Yoshida @ aerith.net 101P at Gary W. Kronk's Cometography For 101P/Chernykh-B Periodic comets 0101 Split comets 19770819

3981194

https://en.wikipedia.org/wiki/Great%20Comet%20of%201680

Great Comet of 1680

C/1680 V1, also called the Great Comet of 1680, Kirch's Comet, and Newton's Comet, was the first comet discovered by telescope. It was discovered by Gottfried Kirch and was one of the brightest comets of the seventeenth century. Overview The comet was discovered by Gottfried Kirch, a German astronomer, on 14 November 1680 (New Style), in Coburg, and it became one of the brightest comets of the seventeenth century – reputedly visible even in daytime – and was noted for its spectacularly long tail. Passing 0.42 au from Earth on 30 November 1680, it sped around an extremely close perihelion of on 18 December 1680, reaching its peak brightness on 29 December as it swung outward. It was last observed on 19 March 1681. JPL Horizons shows the comet has roughly a barycentric orbital period of years. the comet is about from the Sun. While the Kirch Comet of 1680–1681 was discovered by – and subsequently named for – Gottfried Kirch, credit must also be given to Eusebio Kino, the Spanish Jesuit priest who charted the comet’s course. During his delayed departure for Mexico, Kino began his observations of the comet in Cádiz in late 1680. Upon his arrival in Mexico City, he published his Exposición astronómica de el cometa (Mexico City, 1681) in which he presented his findings. Kino’s Exposición astronómica is among the earliest scientific treatises published by a European in the New World. Basil Ringrose was serving under buccaneer Captain Bartholomew Sharpe and made the following observation shortly before raiding the Spanish port city of Coquimbo, Chile: Friday, November 19th, 1680. This morning about an hour before day we observed a comet to appear a degree N. from the bright in Libra. The body thereof seemed dull, and its tail extended itself 18 or 20 degrees in length, being of a pale colour and pointing directly N.N.W. Our prisoners hereupon reported to us that the Spaniards had seen very strange sights, both at Lima, the capital city of Peru, Guayaquil, and other places, much about the time of our coming into the South Seas. Although it was undeniably a sungrazing comet, it was probably not part of the Kreutz family. Isaac Newton used the comet to test and verify Kepler's laws. John Flamsteed was the first to propose that the two bright comets of 1680–1681 were the same comet, one travelling inbound to the Sun and the other outbound, and Newton originally disputed this. Newton later changed his mind, and then, with Edmond Halley's help, purloined some of Flamsteed's data to indeed verify this was the case without giving Flamsteed credit. See also Great comet Halley's Comet Lists of comets References External links The Great Comet of 1680 Over Rotterdam (APOD 28 October 2013) Sungrazing comets Non-periodic comets Great Comet of 1680 16801114 Great comets

3983509

https://en.wikipedia.org/wiki/Effect%20of%20Sun%20angle%20on%20climate

Effect of Sun angle on climate

The amount of heat energy received at any location on the globe is a direct effect of Sun angle on climate, as the angle at which sunlight strikes Earth varies by location, time of day, and season due to Earth's orbit around the Sun and Earth's rotation around its tilted axis. Seasonal change in the angle of sunlight, caused by the tilt of Earth's axis, is the basic mechanism that results in warmer weather in summer than in winter. Change in day length is another factor. Geometry of Sun angle Figure 1 presents a case when sunlight shines on Earth at a lower angle (Sun closer to the horizon), the energy of the sunlight is spread over a larger area, and is therefore weaker than if the Sun is higher overhead and the energy is concentrated on a smaller area. Figure 2 depicts a sunbeam wide falling on the ground from directly overhead, and another hitting the ground at a 30° angle. Trigonometry tells us that the sine of a 30° angle is 1/2, whereas the sine of a 90° angle is 1. Therefore, the sunbeam hitting the ground at a 30° angle spreads the same amount of light over twice as much area (if we imagine the Sun shining from the south at noon, the north–south width doubles; the east–west width does not). Consequently, the amount of light falling on each square mile is only half as much. Figure 3 shows the angle of sunlight striking Earth in the Northern and Southern Hemispheres when Earth's northern axis is tilted away from the Sun, when it is winter in the north and summer in the south. Technical note Heat energy is not received from the Sun. Rather, radiant energy is received and this results in change in energy level of receiving bodies in Earth's domain. Different materials have different properties for transmitting back received energy in the form of heat energy at different rates. See also Axial tilt Declination Solar irradiance (insolation) Sun path References Climate variability and change Seasons Atmospheric radiation

3983697

https://en.wikipedia.org/wiki/Belt%20of%20Venus

Belt of Venus

The Belt of Venus (also called Venus's Girdle, the antitwilight arch, or antitwilight) is an atmospheric phenomenon visible shortly before sunrise or after sunset, during civil twilight. It is a pinkish glow that surrounds the observer, extending roughly 10–20° above the horizon. It appears opposite to the afterglow, which it also reflects. In a way, the Belt of Venus is actually alpenglow visible near the horizon during twilight, above the antisolar point. Like alpenglow, the backscatter of reddened sunlight also creates the Belt of Venus. Though unlike alpenglow, the sunlight scattered by fine particulates that cause the rosy arch of the Belt shines high in the atmosphere and lasts for a while after sunset or before sunrise. As twilight progresses, the arch is separated from the horizon by the dark band of Earth's shadow, or "twilight wedge". The pinkish glow is due to the Rayleigh scattering of light from the rising or setting Sun, which is then backscattered by particulates. A similar effect can be seen on a "blood moon" during a total lunar eclipse. The zodiacal light and gegenschein, which are caused by the diffuse reflection of sunlight from interplanetary dust in the Solar System, are also similar phenomena. The Belt of Venus can be observed as having a vivider pink color during the winter months, as opposed to the summer months, when it appears faded and dim above the yellowish-orange band near the horizon. The name of the phenomenon alludes to the cestus, a girdle or breast-band, of the Ancient Greek goddess Aphrodite, customarily equated with the Roman goddess Venus. Since the greatest elongation (angular separation between the Sun and a Solar System body) of Venus is only 45–48°, the inferior planet never appears in the opposite of the Sun's direction (180° difference in ecliptic longitude) from Earth and is thus never located in the Belt of Venus. See also Anticrepuscular rays Atmospheric refraction Blue hour Earth's shadow Golden hour or Magic hour References External links Shadow of Earth, Belt of Venus as seen over Half Dome, Yosemite National Park, displayed in an interactive panorama. Scroll to the very bottom of the post to view, after all other Yosemite panoramas. Earth phenomena Atmospheric optical phenomena

3988692

https://en.wikipedia.org/wiki/Useful%20conversions%20and%20formulas%20for%20air%20dispersion%20modeling

Useful conversions and formulas for air dispersion modeling

Various governmental agencies involved with environmental protection and with occupational safety and health have promulgated regulations limiting the allowable concentrations of gaseous pollutants in the ambient air or in emissions to the ambient air. Such regulations involve a number of different expressions of concentration. Some express the concentrations as ppmv and some express the concentrations as mg/m3, while others require adjusting or correcting the concentrations to reference conditions of moisture content, oxygen content or carbon dioxide content. This article presents a set of useful conversions and formulas for air dispersion modeling of atmospheric pollutants and for complying with the various regulations as to how to express the concentrations obtained by such modeling. Converting air pollutant concentrations The conversion equations depend on the temperature at which the conversion is wanted (usually about 20 to 25 degrees Celsius). At an ambient air pressure of 1 atmosphere (101.325 kPa), the general equation is: and for the reverse conversion: Notes: Pollution regulations in the United States typically reference their pollutant limits to an ambient temperature of 20 to 25 °C as noted above. In most other nations, the reference ambient temperature for pollutant limits may be 0 °C or other values. 1 percent by volume = 10,000 ppmv (i.e., parts per million by volume). atm = absolute atmospheric pressure in atmospheres mol = gram mole Correcting concentrations for altitude Atmospheric pollutant concentrations expressed as mass per unit volume of atmospheric air (e.g., mg/m3, µg/m3, etc.) at sea level will decrease with increasing altitude because the atmospheric pressure decreases with increasing altitude. The change of atmospheric pressure with altitude can be obtained from this equation: Given an atmospheric pollutant concentration at an atmospheric pressure of 1 atmosphere (i.e., at sea level altitude), the concentration at other altitudes can be obtained from this equation: As an example, given a concentration of 260 mg/m3 at sea level, calculate the equivalent concentration at an altitude of 1,800 meters: Ca = 260 × 0.9877 18 = 208 mg/m3 at 1,800 meters altitude Standard conditions for gas volumes A normal cubic meter (Nm3 ) is the metric expression of gas volume at standard conditions and it is usually (but not always) defined as being measured at 0 °C and 1 atmosphere of pressure. A standard cubic foot (scf) is the USA expression of gas volume at standard conditions and it is often (but not always) defined as being measured at 60 °F and 1 atmosphere of pressure. There are other definitions of standard gas conditions used in the USA besides 60 °F and 1 atmosphere. That being understood: 1 Nm3 of any gas (measured at 0 °C and 1 atmosphere of absolute pressure) equals 37.326 scf of that gas (measured at 60 °F and 1 atmosphere of absolute pressure). 1 kmol of any ideal gas equals 22.414 Nm3 of that gas at 0 °C and 1 atmosphere of absolute pressure ... and 1 lbmol of any ideal gas equals 379.482 scf of that gas at 60 °F and 1 atmosphere of absolute pressure. Notes: kmol = kilomole or kilogram mole lbmol = pound mole Windspeed conversion factors Meteorological data includes windspeeds which may be expressed as statute miles per hour, knots, or meters per second. Here are the conversion factors for those various expressions of windspeed: 1 m/s = 2.237 statute mile/h = 1.944 knots 1 knot = 1.151 statute mile/h = 0.514 m/s 1 statute mile/h = 0.869 knots = 0.447 m/s Note: 1 statute mile = 5,280 feet = 1,609 meters Correcting for reference conditions Many environmental protection agencies have issued regulations that limit the concentration of pollutants in gaseous emissions and define the reference conditions applicable to those concentration limits. For example, such a regulation might limit the concentration of NOx to 55 ppmv in a dry combustion exhaust gas corrected to 3 volume percent O2. As another example, a regulation might limit the concentration of particulate matter to 0.1 grain per standard cubic foot (i.e., scf) of dry exhaust gas corrected to 12 volume percent CO2. Environmental agencies in the USA often denote a standard cubic foot of dry gas as "dscf" or as "scfd". Likewise, a standard cubic meter of dry gas is often denoted as "dscm" or "scmd" (again, by environmental agencies in the USA). Correcting to a dry basis If a gaseous emission sample is analyzed and found to contain water vapor and a pollutant concentration of say 40 ppmv, then 40 ppmv should be designated as the "wet basis" pollutant concentration. The following equation can be used to correct the measured "wet basis" concentration to a "dry basis" concentration: Thus, a wet basis concentration of 40 ppmv in a gas having 10 volume percent water vapor would have a dry basis concentration = 40 ÷ ( 1 - 0.10 ) = 44.44 ppmv. Correcting to a reference oxygen content The following equation can be used to correct a measured pollutant concentration in an emitted gas (containing a measured O2 content) to an equivalent pollutant concentration in an emitted gas containing a specified reference amount of O2: Thus, a measured concentration of 45 ppmv (dry basis) in a gas having 5 volume % O2 is 45 × ( 20.9 - 3 ) ÷ ( 20.9 - 5 ) = 50.7 ppmv (dry basis) of when corrected to a gas having a specified reference O2 content of 3 volume %. Correcting to a reference carbon dioxide content The following equation can be used to correct a measured pollutant concentration in an emitted gas (containing a measured CO2 content) to an equivalent pollutant concentration in an emitted gas containing a specified reference amount of CO2: Thus, a measured particulates concentration of 0.1 grain per dscf in a gas that has 8 volume % CO2 is 0.1 × ( 12 ÷ 8 ) = 0.15 grain per dscf when corrected to a gas having a specified reference CO2 content of 12 volume %. Notes: Although ppmv and grains per dscf have been used in the above examples, concentrations such as ppbv (i.e., parts per billion by volume), volume percent, grams per dscm and many others may also be used. 1 percent by volume = 10,000 ppmv (i.e., parts per million by volume). Care must be taken with the concentrations expressed as ppbv to differentiate between the British billion which is 1012 and the USA billion which is 109. See also Standard conditions of temperature and pressure Units conversion by factor-label Atmospheric dispersion modeling Roadway air dispersion modeling Bibliography of atmospheric dispersion modeling Accidental release source terms Choked flow References External links More conversions and formulas useful in air dispersion modeling are available in the feature articles at www.air-dispersion.com. U.S. EPA tutorial course has very useful information. Atmospheric dispersion modeling Air pollution Environmental engineering

3991526

https://en.wikipedia.org/wiki/Solar%20cycle%20%28calendar%29

Solar cycle (calendar)

The solar cycle is a 28-year cycle of the Julian calendar, and 400-year cycle of the Gregorian calendar with respect to the week. It occurs because leap years occur every 4 years, typically observed by adding a day to the month of February, making it February 29th. There are 7 possible days to start a leap year, making a 28-year sequence. This cycle also occurs in the Gregorian calendar, but it is interrupted by years such as 1700, 1800, 1900, 2100, 2200, 2300 and 2500, which are divisible by four but which are common years. This interruption has the effect of skipping 16 years of the solar cycle between February 28 and March 1. Because the Gregorian cycle of 400 years has exactly 146,097 days, i.e. exactly 20,871 weeks, one can say that the Gregorian so-called solar cycle lasts 400 years. Calendar years are usually marked by Dominical letters indicating the first Sunday in a new year, thus the term solar cycle can also refer to a repeating sequence of Dominical letters. Unless a year is not a leap year due to Gregorian exceptions, a sequence of calendars is reused every 28 years. Sun-based calendars are first thought to be used by the Egyptians, who based it around the annual sunrise of the Dog Star and flooding of the Nile River. See also Birkat Hachama Dominical letter Doomsday rule Friday the 13th Lunar Calendar References Further reading C. R. Cheney (rev. Michael Jones), 2012: Handbook of dates (2nd edition), CUP External links The ISO 8601 calendar using week numbers, explained using Dominical letters. Calendars Gregorian calendar Julian calendar Units of time