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Which European country is committed to decommissioning all of its nuclear reactors?

Nuclear Decommissioning: Decommission nuclear facilities - World Nuclear Association Decommissioning Nuclear Facilities (Updated November 2016) To date, about 110 commercial power reactors, 46 experimental or prototype reactors, over 250 research reactors and a number of fuel cycle facilities have been retired from operation. Some of these have been fully dismantled. Most parts of a nuclear power plant do not become radioactive, or are contaminated at only very low levels. Most of the metal can be recycled. Proven techniques and equipment are available to dismantle nuclear facilities safely and these have now been well demonstrated in several parts of the world. Decommissioning costs for nuclear power plants, including disposal of associated wastes, are reducing and contribute only a small fraction of the total cost of electricity generation. All power plants, coal, gas and nuclear, have a finite life beyond which it is not economically feasible to operate them. Generally speaking, early nuclear plants were designed for a life of about 30 years, though with refurbishment, some have proved capable of continuing well beyond this. Newer plants are designed for a 40 to 60 year operating life. At the end of the life of any power plant, it needs to be decommissioned, cleaned up and demolished so that the site is made available for other uses. For nuclear plants, the term decommissioning includes all clean-up of radioactivity and progressive dismantling of the plant. This may start with the owner's decision to write it off or declare that it is permanently removed from operation. For practical purposes it includes defueling and removal of coolant, though NRC at least defines it as strictly beginning only after fuel and coolant are removed. It concludes with licence termination after decontamination is verified and wastes removed. A Table showing about 150 shutdown reactors is at the end of this paper. About 17 of these have had the full decommissioning process completed as of 2016. Decommissioning Options The International Atomic Energy Agency (IAEA) has defined three options for decommissioning, the definitions of which have been internationally adopted: Immediate Dismantling (or Early Site Release/'Decon' in the US): This option allows for the facility to be removed from regulatory control relatively soon after shutdown or termination of regulated activities. Final dismantling or decontamination activities can begin within a few months or years, depending on the facility. Following removal from regulatory control, the site is then available for re-use. Safe Enclosure ('Safstor') or deferred dismantling: This option postpones the final removal of controls for a longer period, usually in the order of 40 to 60 years. The facility is placed into a safe storage configuration until the eventual dismantling and decontamination activities occur after resudual radioactivity has decayed. There is a risk in this case of regulatory change which could increase costs unpredictably. Entombment (or 'Entomb'): This option entails placing the facility into a condition that will allow the remaining on-site radioactive material to remain on-site without ever removing it totally. This option usually involves reducing the size of the area where the radioactive material is located and then encasing the facility in a long-lived structure such as concrete, that will last for a period of time to ensure the remaining radioactivity is no longer of concern. Each approach has its benefits and disadvantages. National policy determines which approach or combination of approaches is adopted or allowed. In the case of immediate dismantling (or early site release), responsibility for completion of decommissioning is not transferred to future generations. The experience and skills of operating staff can also be utilised during the decommissioning program. Alternatively, Safe Enclosure (or Safstor) allows significant reduction in residual radioactivity, thus reducing radiation hazard during the eventual dismantling. The expected improvements in mechanical techni

Which Canadian city gave its name to the 1987world agreement on protection of the ozone layer?

Effective Communication at Pepsi Co - Term Paper Effective Communication at Pepsi Co Which Indian state is at the eastern end of the Himalayas? A: Assam. What is the name of the atmospheric gas which screens out the sun's harmful ultraviolet radiation? A: Ozone. What is the world's deepest ocean? A: Pacific. Which is the largest animal ever to have inhabited the Earth? A: Blue Whale. What once covered 14% of the Earth's land area, but by 1991 over half had been destroyed? A: Rainforest. Which inland sea between Kazakhstan and Uzbekistan is fast disappearing because the rivers that feed it have been diverted and dammed? A: Aral Sea. The damaged Chernobyl nuclear power station is situated in which country? A: Ukraine. What type of rock is granite? A: Igneous. What type of rock is basalt? A: Igneous. What is the main constituent of natural gas? A: Methane. What is the term for nutrient enrichment of lakes? A: Eutrophication. Which of the Earth's atmospheric layers reflects radio waves? A: Ionosphere. Which gas forms 80% of Earth's atmosphere? A: Nitrogen. In which mountain chain would you find Mount Everest? A: Himalayas. What is the collective term for substances such as coal, oil and natural gas, the burning of which produces carbon dioxide? A: Fossil fuel. What contributes to the greenhouse effect at lower atmospheric levels, but in the upper atmosphere protects life on Earth? A: Ozone. What is the name of the process by which substances are washed out of the soil? A: Leaching. Who was director of the environmental pressure group Friends of the Earth 1984 - 90? A: Jonathon Porritt. Which European country is committed to decommissioning all of its nuclear reactors? A: Sweden. Which Canadian city gave its name to the 1987world agreement on protection of the ozone layer? A: Montreal. Five-legged creatures have damaged which 1250 mile long wonder of the world? A: Great Barrier Reef.

The dodo was a native bird of which island?

The Dodo Bird | History, Story and Resources for Dodobirds The Story of the Dodo Bird A Reference Site for The Dodo Bird and it's History The Dodo bird or Raphus Cucullatus was a flightless bird native to the island of Mauritius, near the island of Madagascar in the Indian Ocean. The closest relatives to the dodo bird are pigeons and doves, even though dodo birds were much larger in size. On average, dodo birds stood 3 feet tall and weighted about 40 lb. Unfortunately, due to aggressive human population, dodo birds became extinct in late 17th century. The Dodo Bird Location Dodo Birds, while now extinct, were found only on the small island of Mauritius, some 500 miles east of Madagascar, and 1200 miles east of Africa. The complete isolation of this island let the Dodo Birds grow and evolve without natural predators, unfortunately to a fault that led to their extinction.

What is the name given to the study of earthquakes?

earthquakes earthquakes adapted to HTML from lecture notes of Prof. Stephen A. Nelson Tulane University Earthquakes Earthquakes occur when energy stored in elastically strained rocks is suddenly released. This release of energy causes intense ground shaking in the area near the source of the earthquake and sends waves of elastic energy, called seismic waves, throughout the Earth. Earthquakes can be generated by bomb blasts, volcanic eruptions , and sudden slippage along faults. Earthquakes are definitely a geologic hazard for those living in earthquake prone areas, but the seismic waves generated by earthquakes are invaluable for studying the interior of the Earth. Origin of Earthquakes Most natural earthquakes are caused by sudden slippage along a fault zone . The elastic rebound theory suggests that if slippage along a fault is hindered such that elastic strain energy builds up in the deforming rocks on either side of the fault, when the slippage does occur, the energy released causes an earthquake. This theory was discovered by making measurements at a number of points across a fault. Prior to an earthquake it was noted that the rocks adjacent to the fault were bending. These bends disappeared after an earthquake suggesting that the energy stored in bending the rocks was suddenly released during the earthquake. Seismology, The Study of Earthquakes When an earthquake occurs, the elastic energy is released and sends out vibrations that travel throughout the Earth. These vibrations are called seismic waves. The study of how seismic waves behave in the Earth is called seismology. Seismographs - Seismic waves travel through the Earth as vibrations. A seismometer is an instrument used to record these vibrations and the resulting graph that shows the vibrations is called a seismograph. The seismometer must be able to move with the vibrations, yet part of it must remain nearly stationary. This is accomplished by isolating the recording device (like a pen) from the rest of the Earth using the principal of inertia. For example, if the pen is attached to a large mass suspended by a spring, the spring and the large mass move less than the paper which is attached to the Earth, and on which the record of the vibrations is made. Seismic Waves (freeware simulation 3.39Megs) . The source of an earthquake is called the focus, which is an exact location within the Earth were seismic waves are generated by sudden release of stored elastic energy. The epicenter is the point on the surface of the Earth directly above the focus. Sometimes the media get these two terms confused. Seismic waves emanating from the focus can travel in several ways, and thus there are several different kinds of seismic waves. Types of Seismic Waves Body Waves - emanate from the focus and travel in all directions through the body of the Earth. There are two types of body waves: P - waves - are Primary waves . They travel with a velocity that depends on the elastic properties of the rock through which they travel. Vp = Ö [(K + 4/3m )/r ] Where, Vp is the velocity of the P-wave, K is the incompressibility of the material, m is the rigidity of the material, and r is the density of the material. S-Waves - Secondary waves , also called shear waves. They travel with a velocity that depends only on the rigidity and density of the material through which they travel: Vs = Ö [( m )/r ] S-waves travel through material by shearing it or changing its shape in the direction perpendicular to the direction of travel. The resistance to shearing of a material is the property called the rigidity. It is notable that liquids have no rigidity, so that the velocity of an S-wave is zero in a liquid. (This point will become important later). Note that S-waves travel slower than P-waves, so they will reach a seismograph after the P-wave. Surface Waves - Surface waves differ from body waves in that they do not travel through the Earth, but instead travel along paths nearly parallel to the surface of the Earth. Surface waves behave like S-waves in that they cause up and down and side to side

Marble is formed by the metamorphosis of which rock?

Marble: Metamorphic Rock: Pictures, Definition, Properties Marble A non-foliated metamorphic rock that forms when limestone is subjected to heat and pressure. Pink Marble: A piece of pink marble about four inches (ten centimeters) across. The pink color is most likely derived from iron. Image by NASA. What is Marble? Marble is a metamorphic rock that forms when limestone is subjected to the heat and pressure of metamorphism. It is composed primarily of the mineral calcite (CaCO3) and usually contains other minerals, such as clay minerals, micas, quartz , pyrite , iron oxides, and graphite . Under the conditions of metamorphism, the calcite in the limestone recrystallizes to form a rock that is a mass of interlocking calcite crystals. A related rock, dolomitic marble, is produced when dolostone is subjected to heat and pressure.   Photo Gallery:   The Many Uses of Marble Ruby in Marble: Marble is often the host rock for corundum, spinel, and other gem minerals. This specimen is a piece of white marble with a large red ruby crystal from Afghanistan. Specimen is about 1 1/4 inches across (about 3 centimeters). Specimen and photo by Arkenstone / www.iRocks.com . How Does Marble Form? Most marble forms at convergent plate boundaries where large areas of Earth's crust are exposed to regional metamorphism. Some marble also forms by contact metamorphism when a hot magma body heats adjacent limestone or dolostone. Before metamorphism, the calcite in the limestone is often in the form of lithified fossil material and biological debris. During metamorphism, this calcite recrystallizes and the texture of the rock changes. In the early stages of the limestone-to-marble transformation, the calcite crystals in the rock are very small. In a freshly-broken hand specimen, they might only be recognized as a sugary sparkle of light reflecting from their tiny cleavage faces when the rock is played in the light. As metamorphism progresses, the crystals grow larger and become easily recognizable as interlocking crystals of calcite. Recrystallization obscures the original fossils and sedimentary structures of the limestone. It also occurs without forming foliation, which normally is found in rocks that are altered by the directed pressure of a convergent plate boundary. Recrystallization is what marks the separation between limestone and marble. Marble that has been exposed to low levels of metamorphism will have very small calcite crystals. The crystals become larger as the level of metamorphism progresses. Clay minerals within the marble will alter to micas and more complex silicate structures as the level of metamorphism increases. Marble Dimension Stone: Marble cut into blocks and slabs of specific size is known as "dimension stone." Photo © iStockphoto / Thomas Lehmann. Physical Properties and Uses of Marble Marble occurs in large deposits that can be hundreds of feet thick and geographically extensive. This allows it to be economically mined on a large scale, with some mines and quarries producing millions of tons per year. Most marble is made into either crushed stone or dimension stone. Crushed stone is used as an aggregate in highways, railroad beds, building foundations, and other types of construction. Dimension stone is produced by sawing marble into pieces of specific dimensions. These are used in monuments, buildings, sculptures, paving and other projects. We have an article about " the uses of marble " that includes photos and descriptions of marble in many types of uses. Gray Marble: This specimen has calcite cleavage faces up to several millimeters in size that are reflecting light. The specimen is about two inches (five centimeters) across. Calcium carbonate medicines: Marble is composed of calcium carbonate. That makes it very effective at neutralizing acids. Highest purity marble is often crushed to a powder, processed to remove impurities, and then used to make products such as Tums and Alka-Seltzer that are used for the treatment of acid indigestion. Crushed marble is also used to reduce the acid cont

Which common water pollutant is believed to be harmful to newborn babies?

Common Newborn Ailments Common Newborn Ailments Comments Alexandra Grablewski Bringing a new baby home from the hospital is a very exciting time. It can also be pretty nerve-racking, especially for first-time moms. Rest assured that your baby is probably perfectly healthy. But keep in mind that there are some common conditions that your baby may experience. Most are nothing to worry too much about, but knowing what to expect can help you determine whether your baby might need medical attention. Read on for eight common conditions to find out what causes them, what to look for, and what treatment might be required. Then relax and enjoy your little one! Jaundice "Physiologic jaundice" is an indicator that a baby's blood contains an excess amount of bilirubin, a chemical formed during the normal breakdown of old red blood cells. We all have some bilirubin in our blood, but newborns usually have higher levels because their young immune system takes longer to process the extra red blood cells present at birth. Signs: A yellowish tint to the skin that usually appears first on the face and then on the chest, abdomen, and legs. To test, gently press on your baby's nose, forehead, or thigh to see if the skin beneath your finger appears yellow. Treatment: Jaundice usually corrects itself within a few days (though it may worsen before it gets better). If it doesn't, you child's pediatrician may do a blood test to determine the bilirubin level. If the level is extremely high and goes untreated, there is a chance that damage to the nervous system can occur. Your doctor may recommend phototherapy -- a treatment in which your baby is placed under special fluorescent-type lights for a day or two. Thrush Thrush is a common yeast infection. Signs: White patches in the mouth Treatment: Your pediatrician will most likely prescribe an oral antifungal medication. Heart Murmur A heart murmur is a noise heard between the beats of the heart. By listening to the heartbeat, doctors can usually classify the murmur by location and timing. Heart murmurs are extremely common, and almost always turn out to be harmless. Signs: A doctor will detect the heart murmur while listening to a baby's heart. Treatment: Normal or "innocent" heart murmurs usually don't require any treatment. If your child's pediatrician is concerned, though, he may refer you to a pediatric cardiologist for special tests. Cradle Cap Redness, greasy scales, and heavy flaking on the scalp are signs of cradle cap -- a condition caused by the buildup of oil and the shedding of skin cells. It looks unattractive, but isn't harmful to your baby. Signs: Scaly patches of skin cells and/or redness appear on the scalp. Treatment: You can treat cradle cap yourself by washing your baby's head with a mild baby shampoo more frequently than normal. Soft brushing can also help remove the scales. If this doesn't work, consult your pediatrician. She may prescribe a stronger shampoo or an ointment. Baby Acne Baby acne or pimples that break out on the face, typically during the fourth or fifth week of life, are harmless. Doctors believe the acne is caused by pregnancy hormones stimulating the oil glands in the skin. Signs: Baby acne looks similar to adult acne. Treatment: Gently wash your baby's face with mild baby soap once a day. Avoid laundering the crib sheets in harsh detergents. Umbilical Granuloma The stump of your baby's umbilical cord should dry up and fall off within a few weeks of birth. On occasion, the base of the cord forms a growth called a granuloma. Signs: The area around the umbilical cord may be moist and swell slightly. The area may be yellowish and could ooze or bleed a little bit. Treatment: Your pediatrician can treat the growth with silver nitrate to dry it out. If that doesn't work, it may have to be removed in a minor procedure. Umbilical Hernia An umbilical hernia is caused by a small hole in the abdominal wall that allows tissue to bulge out when there's pressure inside the abdomen (when a baby cries or strains, for example). Signs: Your baby's umbilical cord seems to push ou

What natural feature covers approximately 6% of the Earth's land surface, and harbors 40% of the Earth's species?

Community and Ecosystem Dynamics COMMUNITY AND ECOSYSTEM DYNAMICS Definitions | Back to Top A community is the set of all populations that inhabit a certain area. Communities can have different sizes and boundaries. These are often identified with some difficulty. An ecosystem is a higher level of organization the community plus its physical environment. Ecosystems include both the biological and physical components affecting the community/ecosystem. We can study ecosystems from a structural view of population distribution or from a functional view of energy flow and other processes. Community Structure | Back to Top Ecologists find that within a community many populations are not randomly distributed. This recognition that there was a pattern and process of spatial distribution of species was a major accomplishment of ecology. Two of the most important patterns are open community structure and the relative rarity of species within a community. Do species within a community have similar geographic range and density peaks? If they do, the community is said to be a closed community , a discrete unit with sharp boundaries known as ecotones . An open community, however, has its populations without ecotones and distributed more or less randomly. In a forest, where we find an open community structure, there is a gradient of soil moisture. Plants have different tolerances to this gradient and occur at different places along the continuum. Where the physical environment has abrupt transitions, we find sharp boundaries developing between populations. For example, an ecotone develops at a beach separating water and land. Open structure provides some protection for the community. Lacking boundaries, it is harder for a community to be destroyed in an all or nothing fashion. Species can come and go within communities over time, yet the community as a whole persists. In general, communities are less fragile and more flexible than some earlier concepts would suggest. Most species in a community are far less abundant than the dominant species that provide a community its name: for example oak-hickory, pine, etc. Populations of just a few species are dominant within a community, no matter what community we examine. Resource partitioning is thought to be the main cause for this distribution. Classification of Communities | Back to Top There are two basic categories of communities: terrestrial (land) and aquatic (water). These two basic types of community contain eight smaller units known as biomes . A biome is a large-scale category containing many communities of a similar nature, whose distribution is largely controlled by climate Terrestrial Biomes: tundra, grassland, desert, taiga, temperate forest, tropical forest. Terrestrial biome distribution is shown in Figure 1. Aquatic Biomes: marine, freshwater. Figure 1. Major terrestrial biomes. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates ( www.sinauer.com ) and WH Freeman ( www.whfreeman.com ), used with permission. Terrestrial Biomes Tundra and Desert The tundra and desert biomes occupy the most extreme environments, with little or no moisture and extremes of temperature acting as harsh selective agents on organisms that occupy these areas. These two biomes have the fewest numbers of species due to the stringent environmental conditions. In other words, not everyone can live there due to the specialized adaptations required by the environment. Tropical Rain Forests Tropical rain forests occur in regions near the equator. The climate is always warm (between 20° and 25° C) with plenty of rainfall (at least 190 cm/year). The rain forest is probably the richest biome, both in diversity and in total biomass. The tropical rain forest has a complex structure, with many levels of life. More than half of all terrestrial species live in this biome. While diversity is high, dominance by a particular species is low. Typical tropical rain forest views are shown in Figure 2. While some animals live on the ground,

What name is given to the huge growths of algae sometimes seen in polluted lakes and rivers?

Trivia Questions for Environmental Science class. - ppt download Presentation is loading. Please wait. Trivia Questions for Environmental Science class. Published by Alexandrina Nicholson Modified about 1 year ago Embed Presentation on theme: "Trivia Questions for Environmental Science class."— Presentation transcript: 1 Trivia Questions for Environmental Science class 2 What is the name of the atmospheric gas which screens out the sun’s harmful UV radiation? a.Oxygen b.Ozone c.Carbon d.Carbon dioxide 3 What is the world’s deepest ocean? a.Pacific b.Atlantic c.Indian d.Arctic 4 Which is the largest animal ever to have inhabited the Earth? a.Blue whale b.Elephant c.Dinosaur d.Giraffe 5 In the United States, how many animals were on the threatened or endangered list as of 2009? a.200 b.750 c.1,200 d.900 6 What percentage of the world’s water is drinkable? a.20% b.60% c.1% d.100% 7 There is a specific name for rain, which contains chemicals that are harmful to the environment. What is this type of rain called? a.Acid pollution b.Acid rain c.Chemical rain d.Precipitation 8 If an item can decompose naturally, it is said to be this. a.Organic b.Biodegradable c.Renewable d.Environmentally friendly 9 Currently, the United States as a nation uses the most energy per annum. Which country comes in second? a.China b.Great Britain c.Japan d.Germany 10 The amount of energy that is saved for every 1,000 pounds of aluminum cans recycled is equivalent to how many gallons of gasoline? a.500 gallons b.1,250 gallons c.250 gallons d.100 gallons 11 Which of the following gases contribute to the effects of global warming? a.Methane b.Carbon dioxide c.Nitrous oxide d.All of these 12 DDT was once a common insecticide. However, it has been determined that it is incredibly harmful to the plant. Exactly, what does DDT affect? a.Water and air b.Soil and air c.Water and soil d.Air and crops 13 Soil erosion can have devastating effects on the planet. Erosion can be reversed by doing what? a.Re-forestation b.Increasing the number of animals in the region c.Re-introducing certain animal species d.Fertilizing soil 14 Littering and garbage removal is a major environmental concern. Which country was the first to implement a garbage removal system? a.United States b.Great Britain c.Germany d.Japan 15 In Canada, where temperatures are often cold, the average person does what with their car to five to ten minutes every day? a.Washes it b.Drives it c.Idles it d.Parks it 16 Fresh water is essential to life on the planet. Which country hosts the largest amount of fresh water? a.Russia b.Canada c.Brazil d.Kenya 17 What kind of animal is essential to more than 100,000 different species of plants? a.Spiders b.Birds c.Bees d.Frogs 18 Air pollution is on a rise. Scientists are able to monitor this increase using which kind of plant? a.Lichen b.Mushrooms c.Giant red woods d.Palm trees 19 What once covered 14% of the Earth’s land area, but by 1991 over half had been destroyed? a.Rainforest b.Oceans c.Mountains d.Sand 20 The damaged Chernobyl nuclear power station is situated in which country? a.Russia b.Ukraine c.Belarus d.Slovakia 21 What is the term for nutrient enrichment for lakes? a.Eutrophication b.Carrying capacity c.Nutrient deprivation d.Nitrification 22 What is the collective term for substances such as coal, oil and natural gas, the burning that produces carbon dioxide? a.Renewable resources b.Natural resources c.Fossil fuels d.Energy 23 Which gas forms 80% of Earths’ atmosphere? a.Oxygen b.Carbon c.Nitrogen d.Carbon dioxide 24 What name is given to the huge growths of algae sometimes seen in polluted lakes and rivers? a.Algal overgrowth b.Algal overproduction c.Algal bloom d.Algal pollution 25 What is the name of the process by which substances are washed out of the soil? a.Nutrient reduction b.Eutrophication c.Nutrient deprivation d.Leaching

What was the name of the dioxin-containing defoliant used during the Vietnam war by the USA army?

Agent Orange - Vietnam War - HISTORY.com Agent Orange A+E Networks Introduction Agent Orange was a powerful mixture of chemical defoliants used by U.S. military forces during the Vietnam War to eliminate forest cover for North Vietnamese and Viet Cong troops, as well as crops that might be used to feed them. The U.S. program of defoliation, codenamed Operation Ranch Hand, sprayed more than 19 million gallons of herbicides over 4.5 million acres of land in Vietnam from 1961 to 1972. Agent Orange, which contained the chemical dioxin, was the most commonly used of the herbicide mixtures, and the most effective. It was later revealed to cause serious health issues–including tumors, birth defects, rashes, psychological symptoms and cancer–among returning U.S. servicemen and their families as well as among the Vietnamese population. Google Operation Ranch Hand and Agent Orange From 1961 to 1972, the U.S. military conducted a large-scale defoliation program aimed at destroying the forest and jungle cover used by enemy North Vietnamese and Viet Cong troops fighting against U.S. and South Vietnamese forces in the Vietnam War . U.S. aircraft were deployed to spray powerful mixtures of herbicides around roads, rivers, canals and military bases, as well as on crops that might be used to supply enemy troops. During this process, crops and water sources used by the non-combatant peasant population of South Vietnam could also be hit. In all, Operation Ranch Hand deployed more than 19 million gallons of herbicides over 4.5 million acres of land. Did You Know? The controversy over Agent Orange and its effects has persisted for more than four decades. As late as June 2011, debate continued over whether so-called "Blue Water Navy" veterans (those who served aboard deep-sea vessels during the Vietnam War) should receive the same Agent Orange-related benefits as other veterans who served on the ground or on inland waterways. The most commonly used, and most effective, mixture of herbicides used was Agent Orange, named for the orange stripe painted on the 55-gallon drums in which the mixture was stored. It was one of several “Rainbow Herbicides” used, along with Agents White, Purple, Pink, Green and Blue. U.S. planes sprayed some 11 million to 13 million gallons of Agent Orange in Vietnam between January 1965 and April 1970. According to the U.S. Department of Veterans Affairs (VA), Agent Orange contained “minute traces” of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), more commonly known as dioxin. Through studies done on laboratory animals, dioxin has been shown to be highly toxic even in minute doses; human exposure to the chemical could be associated with serious health issues such as muscular dysfunction, inflammation, birth defects, nervous system disorders and even the development of various cancers. Agent Orange: Veteran Health Issues and Legal Battle Questions regarding Agent Orange arose in the United States after an increasing number of returning Vietnam veterans and their families began to report a range of afflictions, including rashes and other skin irritations, miscarriages, psychological symptoms, Type-2 diabetes, birth defects in children and cancers such as Hodgkin’s disease, prostate cancer and leukemia. In 1979, a class action lawsuit was filed on behalf of 2.4 million veterans who were exposed to Agent Orange during their service in Vietnam. Five years later, in an out-of-court-settlement, seven large chemical companies that manufactured the herbicide agreed to pay $180 million in compensation to the veterans or their next of kin. Various challenges to the settlement followed, including lawsuits filed by some 300 veterans, before the U.S. Supreme Court confirmed it in 1988. By that time, the settlement had risen to some $240 million including interest. In 1991, President George H.W. Bush signed into law the Agent Orange Act, which mandated that some diseases associated with defoliants (including non-Hodgkin’s lymphomas, soft tissue sarcomas and chloracne) be treated as the result of wartime service and helped codify the VA’

CITES is an international agreement on which environmental problem?

Verification of International Environmental Agreements - J.H. Ausubel and D.G. Victor Verification of International Environmental Agreements Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139 KEY WORDS: monitoring, compliance, regime Abbreviations used: BWU, blue whale unit; CEMS, continuous emissions monitoring systems; CFCs, chlorofluorocarbons; CFE, Treaty on Conventional Armed Forces in Europe; CITES, Convention on International Trade in Endangered Species; CTB, comprehensive test ban; EC, European Community; ECE, United Nations Economic Commission for Europe; EEZ, Exclusive Economic Zone; EMEP, Cooperative Programme for Monitoring and Evaluation of the Long-Range Transmission of Air Pollutants in Europe; GAO, General Accounting Office (U.S. Congress); IAEA, International Atomic Energy Agency; ICES, International Council for the, Exploration of the Seas; IMCO, Inter-governmental Maritime Consultative Organization (IMCO after 1981); IMO, International Maritime Organization (IMCO before 1981); INF, Intermediate Nuclear Forces Treaty; IOS, International Observer System; IUCN, International Union for the Conservation of Nature (recently renamed to World Conservation Union); IWC, International Whaling Commission; LRTAP, Convention on Long Range Transboundary Air Pollution; LTB (T), Limited Test Ban (Treaty); MARPOL, Convention for the Prevention of Pollution from Ships; MSY, maximum sustainable yield; NAAQS, National Ambient Air Quality Standards (U.S.); NGOs, nongovernmental organizations; NEAFC, Northeast Atlantic Fisheries Commission; NPT, Nuclear Non-proliferation Treaty; NTM, national technical means; OECD, Organization for Economic Cooperation and Development; OSHA, Occupational Safety and Health Administration (U.S.); OSL, on-site inspection; OSIA, On-site Inspection Agency (U.S.); SALT, Strategic Arms Limitation Talks; TAC, total allowable catch; UNEP, United Nations Environment Programme. INTRODUCTION Problems and opportunities frequently cross national borders. Informal and formal international arrangements-loosely termed "regimes," defined here as systems of rule or government that have widespread influence--are for the collective management of such transboundary issues. Regimes are pervasive; their number and extent have grown markedly in the 20th century, especially since the Second World War. Students of the international system study the conditions under which regimes are formed and the factors that contribute to their success. These include distribution of power among states, the nature of the issue, its linkages to other issues, the roles and functions of international organizations, the processes of bargaining and rule-maldng, and the influence of domestic politics (1-3). Scholars also theorize how regimes are maintained and changed (4-6). In the past two decades students of international cooperation have increasingly applied their tools to issues of the environment and natural resources (7-9). A few studies have critically assessed international cooperation for transboundary environmental protection and drawn tentative conclusions on factors that lead to effective international regimes (8, 10-12). Studies of local management of common natural resources also yield relevant lessons for international environmental cooperation (13). For several reasons, assessing the effectiveness of international environmental agreements requires study of how compliance is verified. International agreements that are verifiable are more likely to succeed in both negotiation and implementation. The process of verification builds confidence in existing formal and informal agreements, thus improving the prospects for future cooperation and compliance. Verification activities produce information that can provide the technical basis for future agreements and shared understanding. Such information also can provide the basis for sanctions, which depend upon timely, legitimate, and accurate information. Information from verification activities helps to assess how effectively a regime has met its goals and whethe

What prevents the earth's atmosphere from floating out into space?

NOAA/NASA SciJinks :: Why does the atmosphere not drift off into space? Why does the atmosphere not drift off into space? The answer in a word is... Gravity Fortunately for us, Earth’s gravity is strong enough to hold onto its atmosphere. Mars, for example, is less than half Earth’s size and around one-tenth Earth’s mass. Less mass means less gravitational pull. Mars’ atmosphere is only about 1/100th as dense as Earth’s. And, by the way, it is mostly CO2. The air at the bottom of the atmosphere is under a lot more weight than the air nearer the top. Like the acrobat at the bottom of a stack of acrobats, the air at the bottom of the atmosphere is under a lot more weight than the air nearer the top. That means, the air nearer Earth’s surface is squished by the air above it, and is thus denser. The higher you go in the atmosphere, the thinner the air becomes. Ninety-nine percent of the air is in the lowest 30 kilometers (19 miles) of the atmosphere. Yes, Earth’s atmosphere has weight. So we, here at the surface, at the bottom of the “stack,” have about 14.7 pounds of air pressing down on every square inch of our bodies! Fortunately, we’re used to it. We evolved down here, so our bodies can handle it. Higher in the atmosphere we begin to have problems. Even at 3,000 — 4,500 meters (around 10 — 15,000 feet) altitude, the air becomes thin enough that most people have trouble getting enough oxygen. If Earth were the size of a beach ball, the breathable atmosphere would be as thin as paper. Seeing our atmosphere from space shows us how thin and fragile it is. "Many astronauts have reported seeing that delicate, thin blue aura at the horizon of the daylit hemisphere - that represents the thickness of the entire atmosphere - and immediately, unbidden, contemplating its fragility and vulnerability. They worry about it. They have reason to worry.” Carl Sagan, Billions & Billions If each acrobat weighs 100 pounds, how much weight does each acrobat hold up? Is there any wonder the bottom acrobat is starting to look a little squashed?

Which of the emissions from cars are acidic?

Vehicle Emission Controls Vehicle Emission Controls Think Energy Vehicle Emission Controls Through emissions of nitrogen oxides , cars and other road vehicles are major contributors to acidic emissions which cause acid rain. In all countries of the industrialised world, the number of vehicles on the roads has been continually increasing since the 1970s. With a large rise in traffic numbers, it becomes increasingly important to keep pollutant emissions to a minimum. There are presently a number of ways in which road traffic pollution can be reduced, including the use of emission control technology solutions. Since January 1993, all new cars sold in the European Union have been fitted with a catalytic converter. Most catalytic converters lead to a dramatic reduction in emissions of nitrogen oxides , as well as other harmful pollutants. Exhaust Gas Recirculation involves returning exhaust air to the fuel inlet, which results in a reduction in peak engine temperatures and emissions of nitrogen oxides from petrol vehicles. Smaller, lighter cars use less fuel and hence produce less pollution. Technological development using lighter materials for construction may therefore reduce emissions. The above technologies all provide a reduction in emissions from vehicles. Electric transport is an alternative development that could lead to a large reduction in acidic pollution at ground level, if it became more wide spread. Electric transport produces no emissions at the point of use, although pollution is emitted during the production of electricity from power stations . The main drawback for electric vehicles is the need to recharge batteries. In addition, although they have lower fuel and maintenance costs than petrol and diesel, at present they require a higher capital investment. The technical fixes such as those outlined above need to be combined with management schemes to reduce traffic in city centres, education to encourage the public to use their cars less, and the further development of alternative fuels that are not harmful to the environment.

Which quarry in the Italian region of Tuscany is renowned for the quality of its marble?

Tuscany Travel Guide Share The sunny Italian region of Tuscany provides infinite allure for travelers. Artists, winemakers, monks and merchants make their home in the rustic medieval hilltop hamlets, rolling hills of olives and wine, bucolic farmlands strewn with poppies and sunflowers, and marvelous cities such as Florence. Read on to discover our favorite Tuscan treasures. Florence – The Streets Less Traveled The large crowds that visit Florence in the summer can make it feel a bit like Disneyland. To find real Florentine flavor and space to breathe, cross one of the three bridges over the Arno River to the district. Less crowded than the other side, its medieval backstreets are a labyrinth of picturesque lanes, alleyways, nooks and crannies. While you should definitely try to see attractions like Pitti Palace , the lovely Boboli Garden and the lesser-known Bardini Gardens beyond it, when you get to Oltrarno, leave the map behind and just wander. Let yourself be surprised by narrow lanes that open onto a piazza, antique shops and artisan studios where contemporary craftsmen continue Florentine traditions such as sculpture, leathercraft, metalwork, woodwork, goldsmithing and bookbinding. Superb family-style trattorias feature fresh and simple ingredients—and are mostly undiscovered by tourists. Practice your Italian in small markets, cafés and gelaterias as you sample local specialties and explore piazzas like Santo Spirito and Piazza Pitti. Florence – Medieval Church with a Breathtaking View Signs lead the way to a medieval hilltop church beyond Oltrarno and the old city walls of Florence. The story of San Miniato al Monte goes back to 250 A.D., when St. Minias—an Armenian prince turned Christian hermit—was beheaded for his faith. Legend has it that St. Minias carried his own head over the Arno River and made his way up the hillside that overlooks Florence, where he laid himself to rest. The church was built in his honor in 1013, with an adjoining monastery erected around it. Michelangelo looked after the church during the Siege of Florence (1530), devising a plan of defense that included placing two cannons on top of the bell tower and hanging monks’ mattresses from its walls to absorb the impact from incoming cannonballs. Meticulously planned, the church is filled with fascinating symbolism , geometry and zodiacs (its façade resembles an owl). Impressive frescoes can be found inside and out. The adjoining gift shop sells honey, soap and liqueurs made by the monks. On summer weekdays, the monks accompany mass with Gregorian chants in the crypt at 5:30 p.m. Day or night, regardless of the season, the view is outstanding. Arezzo – A Medieval Pot of Gold Southeast of Florence, Arezzo presides on a hill overlooking four valleys. A haven of goldsmiths and jewelers, it’s also home to boutique shops and beautiful Renaissance and Romanesque architecture of red brick, stucco and stone. Monuments, churches and museums like the Casa di Giorgio Vasari provide historical and artistic interest, while small alleyways, piazzas, quiet streets and the Corso Italia—a pedestrian-only avenue to the old city center­—make it a great, uncrowded place to explore on foot. The steeply graded Piazza Grande in the old town marks the center of this ancient commune and features a town hall that dates back to the 6th century. Take a seat at one of the surrounding cafés for a cool drink, gelato or panini. Pop into the town’s tavernas and trattorias to sample local specialties like acquacotta (peasant bread soup made with porcini mushrooms), ribollita (a bean and vegetable soup) and the famous Chianina steak (aka Bistecca Fiorentina), paired with one of the area’s fantastic wines. Summer events in Arezzo provide great souvenir shopping and entertainment. On the first Sunday of the first full weekend of each month, an antique fair is staged on the Piazza Grande. Spilling over to adjacent streets, hundreds of stalls offer everything from wrought-iron implements, cooking utensils and furniture to art prints, paintings, books and handblown glass. In June

What is the name given to the geological time period of 363-290 million years ago during which coal measures were formed?

Geologic Time Scale Geologic time scale From Wikipedia, the free encyclopedia: http://en.wikipedia.org/wiki/Geologic_time_scale See notes at the ends of "Major events" about carbon dioxide concentrations. The geologic time scale is a chronologic schema (or idealized Model ) relating stratigraphy to time that is used by geologists and other earth scientists to describe the timing and relationships between events that have occurred during the history of Earth . The table of geologic time spans presented here agrees with the dates and nomenclature proposed by the International Commission on Stratigraphy , and uses the standard color codes of the United States Geological Survey . Evidence from radiometric dating indicates that the Earth is about 4.570 billion years old. The geological or deep time of Earth's past has been organized into various units according to events which took place in each period. Graphical timelines The second and third timelines are each subsections of their preceding timeline as indicated by asterisks. Millions of Years The Holocene (the latest epoch ) is too small to be shown clearly on this timeline. Terminology Chron Generic term for any identifiable time period; not necessarily part of a hierarchy The largest defined unit of time is the supereon, composed of eons. Eons are divided into eras, which are in turn divided into periods, epochs and ages. The terms eonothem , erathem , system , series , and stage are used to refer to the layers of rock that correspond to these periods of geologic time. Geologists tend to talk in terms of Upper/Late, Lower/Early and Middle parts of periods and other units , such as "Upper Jurassic ", and "Middle Cambrian ". Upper, Middle, and Lower are terms applied to the rocks themselves, as in "Upper Jurassic sandstone ," while Late, Middle, and Early are applied to time, as in "Early Jurassic deposition " or " fossils of Early Jurassic age." The adjectives are capitalized when the subdivision is formally recognized, and lower case when not; thus "early Miocene" but "Early Jurassic." Because geologic units occurring at the same time but from different parts of the world can often look different and contain different fossils, there are many examples where the same period was historically given different names in different locales. For example, in North America the Lower Cambrian is referred to as the Waucoban series that is then subdivided into zones based on trilobites . The same timespan is split into Tommotian , Atdabanian and Botomian stages in East Asia and Siberia . A key aspect of the work of the International Commission on Stratigraphy is to reconcile this conflicting terminology and define universal horizons that can be used around the world.[ citations needed ] History of the time scale See the main articles: history of geology and history of paleontology . Earth history mapped to 24 hours The first geologic time scale was proposed in 1913 by the British geologist Arthur Holmes . [2] He greatly furthered the newly created discipline of geochronology and published the world renowned book The Age of the Earth in 1913 in which he estimated the Earth 's age to be at least 1.6 billion years. [3] Aristotle realized that fossil seashells from rocks were similar to those found on the beach, indicating the fossils were once living animals. He deduced that the positions of land and sea had changed and these changes occurred over long periods of time. Leonardo da Vinci concurred with Aristotle's view that fossils were the remains of ancient life. [4] One of the principles underlying geologic time scales was the principle of superposition of strata, first proposed in the 11th century by the Persian geologist , Avicenna (Ibn Sina). However, he rejected the explanation of fossils as organic remains. [5] While discussing the origins of mountains in The Book of Healing in 1027, he outlined the principle as follows: [6] [7] "It is also possible that the sea may have happened to flow little by little over the land consisting of both plain and mountain, and then have ebbed awa

Which is further north, the tropic of cancer or the tropic of Capricorn?

The Equator, Tropic of Cancer and Tropic of Capricorn By Matt Rosenberg Updated August 31, 2016. Three of the most significant imaginary lines running across the surface of the Earth are the equator, the Tropic of Cancer, and the Tropic of Capricorn. While the equator is the longest line of latitude on the Earth (the line where the Earth is widest in an east-west direction), the tropics are based on the sun's position in relation to the Earth at two points of the year. All three lines of latitude are significant in their relationship between the Earth and the sun. The Equator The equator is located at zero degrees latitude . The equator runs through Indonesia, Ecuador, northern Brazil, the Democratic Republic of the Congo , and Kenya, among other countries . It is 24,901.55 miles (40,075.16 kilometers) long. On the equator, the sun is directly overhead at noon on the two equinoxes - near March and September 21. The equator divides the planet into the Northern and Southern Hemispheres. On the equator, the length of day and night are equal every day of the year - day is always twelve hours long and night is always twelve hours long. continue reading below our video Overview of the Four Seasons The Tropic of Cancer and The Tropic of Capricorn The Tropic of Cancer and the Tropic of Capricorn each lie at 23.5 degrees latitude. The Tropic of Cancer is located at 23.5° North of the equator and runs through Mexico, the Bahamas, Egypt, Saudi Arabia , India, and southern China. The Tropic of Capricorn lies at 23.5° South of the equator and runs through Australia, Chile, southern Brazil (Brazil is the only country that passes through both the equator and a tropic), and northern South Africa . The tropics are the two lines where the sun is directly overhead at noon on the two solstices - near June and December 21. The sun is directly overhead at noon on the Tropic of Cancer on June 21 (the beginning of summer in the Northern Hemisphere and the beginning of winter in the Southern Hemisphere) and the sun is directly overhead at noon on the Tropic of Capricorn on December 21 (the beginning of winter in the Northern Hemisphere and the beginning of summer in the Southern Hemisphere). The reason for the location of the Tropic of Cancer and the Tropic of Capricorn at 23.5° north and south respectively is due to the axial tilt of the Earth. The Earth is titled 23.5 degrees from the plane of the Earth's revolution around the sun each year. The area bounded by the Tropic of Cancer on the north and Tropic of Capricorn on the south is known as the "tropics." This area does not experience seasons because the sun is always high in the sky. Only higher latitudes, north of the Tropic of Cancer and south of the Tropic of Capricorn, experience significant seasonal variation in climate. Realize, however, that areas in the tropics can be cold. The peak of Mauna Kea on the big island of Hawaii stands nearly 14,000 feet above sea level, and snow is not unusual. If you live north of the Tropic of Cancer or south of the Tropic of Capricorn, the sun will never be directly overhead. In the United States, for example, Hawaii is the only location in the country that is south of the Tropic of Cancer, and it is thus the only location in the United States where the sun will be directly overhead in the summer.. Prime Meridian While the equator divides the Earth into Northern and Southern Hemispheres , it is the Prime Meridian at zero degrees longitude and the line of longitude opposite the Prime Meridian (near the International Date Line ) at 180 degrees longitude that divides the Earth into the Eastern and Western Hemispheres . The Eastern Hemisphere consists of Europe, Africa, Asia, and Australia while the Western Hemisphere includes North and South America . Some geographers place the boundaries between the hemispheres at 20° West and 160° East so as to not run through Europe and Africa. Unlike the equator and the Tropic of Cancer and the Tropic of Capricorn, the Prime Meridian and all lines of longitude are completely imaginary lines and have no significance w

What name is given to your angular distance on the Earth's surface relative to the equator?

Latitude and Longitude General Information CALCULATORS and CONVERTERS | Back Latitude and Longitude General Information The earth is effectively a sphere, so how do we describe where a point is on its surface? The most common way to locate points on the surface of the Earth is by standard, geographic coordinates called latitude and longitude. These coordinates values are measured in degrees (of arc, not temperature), and represent angular distances calculated from the center of the Earth. However, there are several CORRECT ways to designate them and to use the different values. What is latitude? We can imagine the Earth as a sphere, with an axis around which it spins. The ends of the axis are the North and South Poles. The Equator is a line around the earth, an equal distance from both poles. The Equator is also the latitude line given the value of zero degrees. This means it is the starting point for measuring latitude, up and down, or North and South properly indicated. Latitude values indicate the angular distance between the Equator and points North or South of it on the surface of the Earth. A line connecting all the points with the same latitude value is called a line of latitude. This term is usually used to refer to the lines that represent values in whole degrees. All lines of latitude are parallel to the Equator (and to each other), and they are sometimes also referred to as parallels. Parallels are equally spaced but they do NOT have the same distance around them! There are 90 degrees of latitude going North from the Equator, and the North Pole is at 90 degrees N. There are 90 degrees to the South of the Equator, and the South Pole is at 90 degrees S. Both are obviously the most distant points from any point on the Equator. When the directional designators (N, S, E or W) are omitted, northern latitudes are given positive values and southern latitudes are given negative values. The Prime Meridian is the alpha and omega of the lines of longitude, called meridians. They run perpendicular to lines of latitude, and all pass through both poles. Each longitude line is part of a great circle. There is no obvious zero degree point for longitude, as there is for latitude. Throughout history many different starting points have been used to measure longitude. By international agreement, the meridian line through Greenwich, England, is currently given the value of zero degrees of longitude; this meridian is referred to as the Prime Meridian. Longitude values are indicate the angular distance between the Prime Meridian and points east or west of it on the surface of the Earth. The Earth is divided equally into 360 degrees of longitude. There are 180 degrees of longitude to the east of the Prime Meridian; when the directional designator is omitted these longitudes are given positive values. There are also 180 degrees of longitude to the west of the Prime Meridian; when the directional designator is omitted these longitudes are given negative values. The 180 degree longitude line is opposite the Prime Meridian on the globe, and is the same going either east or west. How precise can we be with latitude and longitude? Degrees of latitude and longitude can be further subdivided into minutes and seconds (units of arc, not time): There are 60 minutes (') per degree, and 60 seconds (") per minute. For example, a coordinate might be written 65° 32' 15". Degrees can also be expressed as decimals: 65.5375, degrees and decimal minutes: 65° 32.25', or even degrees, minutes, and decimal seconds: 65° 32' 15.275". All these notations allow us to locate places on the Earth quite precisely – to within inches, depending on the accuracy of the equipment doing the measurement. A degree of latitude is approximately 69 miles, and a minute of latitude is approximately 1.15 miles. A second of latitude is approximately 0.02 miles, or just over 100 feet. A degree of longitude varies in size. At the equator, it is approximately 69 miles, the same size as a degree of latitude. The size gradually decreases to zero as the meridians converge at the poles.

Which landlocked Asian country is described as the world's 'highest rubbish dump' because of all the refuse left behind by expeditions?

Asia Times Online :: Letters     Letters      Please provide your name or a pen name, and your country of residence. Lengthy letters run the risk of being cut. Please note: This Letters page is intended primarily for readers to comment on ATol articles or related issues. It should not be used as a forum for readers to debate with each other. The Edge is the place for that. The editors do not mind publishing one or two responses to a reader's letter, but will, at their discretion, direct debaters away from the Letters page. Letters 2013 [Re Jeju port rises to territorial challenge , Dec 19, 2013] Sung Chan Kim and Seok-ho Kang swiftly concludes the obvious as a response to China's initiative in the South Asia Sea. They are too quick to pat themselves on the back. The construction of a military industrial port on Jeju was quickly understood from the very germ of the idea. In other words, South Korea had China very much in its cross hairs. Now that Beijing is flexing crudely its geopolitical muscle, South Korea rushes into to proclaim to the world see how prescient we were to anticipate China's moves. Stuff and nonsense, since Seoul and its US protector's project initially was a red flag to a resurgent China. Nakamura Junzo Guam (Dec 20, '13) [Re China vs US 'sea-to-shining-sea' , Dec 18, '13] Letďż˝s see. US Vice President Joe Biden was in China a couple weeks ago; coincidentally, Apple Inc announced a tentative partnership with China Mobile, thereby greatly increasing the devices companyďż˝s potential customer base. Seems both the Americans and the Chinese understand very well that (geo)politics largely serves economics. On the other hand, the countries that fail to fully grasp this relationship will likely be left holding an empty bag once the economic train has left the station. (But I suppose they all can feel good about themselves by patting one another on the back.) John Chen USA (Dec 20, '13) [Re Uyghurs shot dead in Xinjiang violence , Dec 19, '13] I do not know what type of veil would be used by a Uyghur Chinese woman though there are Muslim fundamentalists who cover their whole face except for the pair of eyes. If this was the case, the police have the right to lift the veil to identify the person. The police chief, Memet Sidiq, must have known the tradition as he himself is a Uyghur Chinese. Besides, attacking police is never allowed in any country, not even in the US. This is the third article submitted by RFA's Uyghur Service on this issue. They have made Asia Times Online a forum to justify their violent acts. Wendy Cai United States (Dec 20, '13) Some time next year the US will "officially" withdraw its armed forces from Afghanistan. I doubt that we'll see the last commanding Amerikan general cross a bridge behind a tank like the Soviets did in 1989, or see TV images of hapless Amerikans and luckless Afghans climbing desperately onto fleeing helicopters from the Kabul Embassy roof a la Saigon 1975. Of course, the Empire is not about to abandon a 13 year war without some kind of intelligence and military presence remaining behind, if for no other reason than to act as a figleaf to mask the debacle. But make no mistake about it; the Empire has been decisively defeated, if not humiliated, by the ragtag Afghan insurgency and its not-so-invisible supporters. The humiliation comes not so much for the fact that the allegedly mightiest military machine in the history of planet earth was unable to quell a fifth rate insurrection in the Third World (Vietnam had already proven that was possible) as from the fact that our alleged most important regional allies, Saudi Arabia and Pakistan, betrayed, manipulated and subverted every move we made in Afghanistan, with impunity, gall and, in the case of Pakistan, an open hand demanding ever more money, weapons and political support. They played Uncle Sam for the sucker he still very much is. Both Muslim countries actively funded, supported and trained the Ta

What name is given to the layer of the atmosphere closest to the surface of the Earth?

Layers of the Atmosphere Layers of the Atmosphere By Matt Rosenberg Updated October 20, 2016. The earth is surrounded by the atmosphere, which is the body of air or gasses that protects the planet and enables life. Most of our atmosphere is located close to the earth's surface where it is most dense. The air of our planet is 79% nitrogen and just under 21% oxygen; the small amount remaining is composed of carbon dioxide and other gasses. There are five distinct layers of the earth. Let's look at each, from closest to farthest from the earth. Troposphere The layer of the atmosphere closest to the earth is the troposphere. This layer is where weather occurs. It begins at the surface of the earth and extends out to about 4-12 miles. The temperature of the troposphere decreases with height. This layer is known as the lower atmosphere. Stratosphere Above the troposphere is the stratosphere, which extends to about 30-35 miles above the earth's surface. Temperature rises within the stratosphere but still remains well below freezing. Mesosphere From about 35 to 50 miles above the surface of the earth lies the mesosphere, where the air is especially thin and molecules are great distances apart. continue reading below our video What are the Seven Wonders of the World Temperatures in the mesosphere reach a low of -184°F (-120°C). The stratosphere and the mesosphere are the middle atmospheres. Thermosphere The thermosphere rises several hundred miles above the earth's surface, from 50 miles up to about 400 miles. Temperature increases with height and can rise to as high as 3,600°F (2000°C). Nonetheless, the air would feel cold because the hot molecules are so far apart. This layer is known as the upper atmosphere. Exosphere Extending from the top of the thermosphere to 6200 miles (10,000 km) above the earth is the exosphere. This layer has very few atmospheric molecules, which can escape into space. Pauses Between each layer of the atmosphere is a boundary. Above the troposphere is the tropopause; above the stratosphere is the stratopause; above the mesosphere is the mesopause; and above the thermosphere is the thermopause. At these "pauses," maximum change between the "spheres" occur.

What name is given to the Earth's single continent, which existed 250 million years ago?

The name of Earth's single, huge continent from over 250 million years ago is (1 point) A.Megaland. B.Pangaea. C.Gondwanaland. D.Laurasia. You have new items in your feed. Click to view. Question and answer The name of Earth's single, huge continent from over 250 million years ago is (1 point) A.Megaland. B.Pangaea. C.Gondwanaland. D.Laurasia. The name of the Earth's single continent was B. Pangaea Get an answer The name of Earth's single, huge continent from over 250 million years ago is (1 point) A.Megaland. B.Pangaea. C.Gondwanaland. D.Laurasia. Original conversation User: The name of Earth's single, huge continent from over 250 million years ago is (1 point) A.Megaland. B.Pangaea. C.Gondwanaland. D.Laurasia. Weegy: The name of the Earth's single continent was B. Pangaea MrG |Points 1812| User: Krystal Weegy: The name of Earth's single, huge continent from over 250 million years ago is B.- Pangaea Expert answered| hhaokok |Points 32|

What component of CFCs causes destruction of ozone?

NASA Earth Observatory (Illustration courtesy Barbara Summey, SSAI)   Understanding Stratospheric Ozone Depletion    Our understanding of stratospheric ozone depletion has been obtained through a combination of laboratory studies, computer models, and atmospheric observations. The wide variety of chemical reactions that occur in the stratosphere have been discovered and studied in laboratory studies. Chemical reactions between two gases follow well-defined physical rules. Some of these reactions occur on the surfaces of polar stratospheric clouds (PSCs) formed in the winter stratosphere. Reactions have been studied that involve many different molecules containing chlorine, bromine, fluorine, and iodine and other atmospheric constituents such as carbon, oxygen, nitrogen, and hydrogen. These studies have shown that several reactions involving chlorine and bromine directly or indirectly destroy ozone in the stratosphere.    Computer models have been used to examine the combined effect of the large group of known reactions that occur in the stratosphere. These models simulate the stratosphere by including representative chemical abundances, winds, air temperatures, and the daily and seasonal changes in sunlight. These analyses show that under certain conditions chlorine and bromine react in catalytic cycles in which one chlorine or bromine atom destroys many thousands of ozone molecules. Models are also used to simulate ozone amounts observed in previous years as a strong test of our understanding of atmospheric processes and to evaluate the importance of new reactions found in laboratory studies. The responses of ozone to possible future changes in the abundances of trace gases, temperatures, and other atmospheric parameters have been extensively explored with specialized computer models .    Atmospheric observations have shown what gases are present in different regions of the stratosphere and how their abundances vary. Gas and particle abundances have been monitored over time periods spanning a daily cycle to decades. Observations show that halogen source gases and reactive halogen gases are present in the stratosphere at the amounts required to cause observed ozone depletion. Ozone and chlorine monoxide (ClO), for example, have been observed extensively with a variety of instruments. ClO is a highly reactive gas that is involved in catalytic ozone destruction cycles throughout the stratosphere . Instruments on the ground and on satellites, balloons, and aircraft now routinely detect ozone and ClO remotely using optical and microwave signals. High-altitude aircraft and balloon instruments are also used to detect both gases locally in the stratosphere . The observations of ozone and reactive gases made in past decades are used extensively in comparisons with computer models in order to increase confidence in our understanding of stratospheric ozone depletion.   The stratospheric ozone layer shields life on Earth from the Sun’s harmful ultraviolet radiation. Chemicals that destroy ozone are formed by industrial and natural processes. With the exception of volcanic injection and aircraft exhaust, these chemicals are carried up into the stratosphere by strong upward-moving air currents in the tropics. Methane (CH4), chlorofluorocarbons (CFCs), nitrous oxide (N2O) and water are injected into the stratosphere through towering tropical cumulus clouds. These compounds are broken down by the ultraviolet radiation in the stratosphere. Byproducts of the breakdown of these chemicals form “radicals”—such as nitrogen dioxide (NO2) and chlorine monoxide (ClO)—that play an active role in ozone destruction. Aerosols and clouds can accelerate ozone loss through reactions on cloud surfaces. Thus, volcanic clouds and polar stratospheric clouds can indirectly contribute to ozone loss.       Stratospheric air temperatures in both polar regions reach minimum values in the lower stratosphere in the winter season. Average minimum values over Antarctica are as low as –90°C in July and August in a ty

What does a barometer measure?

What Does a Barometer Measure? | Wonderopolis Wonder of the Day #213 What Does a Barometer Measure? What does a barometer measure? How much pressure does the atmosphere exert on you at all times? How do changes in air pressure signal changes in the weather? Tags: Listen Can you feel the pressure ? It's around you…all the time…everywhere you go. What is it? Atmospheric pressure — often referred to simply as air pressure — is the constant force exerted on you by the weight of little particles of air. These tiny air particles, called air molecules, can't be seen, but they are all around you. They have weight, which means they constantly “push" down on you. If you look straight up in the air, you can imagine a tall column of air above your head reaching all the way to the edge of the Earth's atmosphere . The weight of that column of air is the amount of air pressure exerted on you. If you move to a higher elevation (climb a mountain, for example), the air pressure will be lower. Why? The length of that column of air above you has decreased by the amount of your increase in elevation . As you move to a higher elevation , you may notice that your ears have to “pop." This balances the pressure between the inside and outside of your ear. Since there are fewer air molecules the higher you go, you will also probably need to breathe faster to breathe in more molecules to make up for the deficit . Air molecules also take up space. Because there tends to be a lot of empty space between air molecules, air can either fill a big area or it can be compressed to fit into a smaller area. When it's compressed, air is said to be under high pressure . Earth's atmosphere presses down on you with a force of almost 15 pounds per square inch. You may be wondering why it doesn't feel that heavy or why you're not crushed under the weight. Remember that thing you do called breathing? The air inside your body balances out the pressure from air in the atmosphere , which prevents you from being squished by the pressure of the atmosphere . You don't sense air pressure as a constant force , because the air inside you balances outside pressure and you're used to that feeling. If you watch the weather report frequently, you're sure to hear the weatherman talk about barometric pressure . Weather forecasters use a special tool called a barometer to measure air pressure . Barometers measure atmospheric pressure using mercury , water or air. You'll usually hear forecasters give measurements in either inches of mercury or in millibars (mb). Forecasters use changes in air pressure measured with barometers to predict short-term changes in the weather . Changes in air pressure signal the movement of high- or low- pressure areas of air, called fronts. Air molecules in high pressure areas tend to flow toward low pressure areas. We call this flow of air molecules wind . The larger the difference in pressure between areas, the stronger the winds will be. As weather forecasters monitor air pressure , falling barometer measurements can signal that bad weather is on the way. In general, if a low pressure system is on its way, be prepared for warmer weather with storms and rain. If a high pressure system is coming, you can expect clear skies and cooler temperatures. Wonder Words (18) Test your knowledge Wonder What's Next? We’re about to erupt with excitement. Join us in Wonderopolis tomorrow for a Wonder of the Day that will blow your top! Try It Out How's the weather? Gather together a few friends or family members to check out one or more of the following fun activities: How accurate is the weatherman where you live? Keep track and find out! Over the course of the next week, watch the weather report at the same time each day. Take notes in a journal. Make sure to record predictions for temperature and precipitation. Then make careful observations about the weather on your own. Did the weatherman get it right? How often? Would you like to be a weather forecaster one day? Why or why not? Are you ready to predict the weather? You can be a weather forecaster in the making

What is the basic chemical composition of malachite?

Malachite: Uses and properties of the mineral and gemstone Home » Minerals » Malachite Malachite Used as an ore of copper, a pigment, a gemstone, and a sculptural material for thousands of years. Malachite Gemstones: A malachite cabochon (30x40 millimeter) and a malachite puffed heart, both cut from rough mined in the Democratic Republic of the Congo. This oval cabochon shows the agate-like banding in various shades of green that is typical of malachite. The puffed heart shows concentric structures. What is Malachite? Malachite is a green copper carbonate hydroxide mineral with a chemical composition of Cu2(CO3)(OH)2. It was one of the first ores used to produce copper metal. It is of minor importance today as an ore of copper because it is usually found in small quantities and can be sold for higher prices for other types of use. Malachite has been used as a gemstone and sculptural material for thousands of years and is still popular today. Today it is most often cut into cabochons or beads for jewelry use. Malachite has a green color that does not fade over time or when exposed to light. Those properties, along with its ability to be easily ground to a powder, made malachite a preferred pigment and coloring agent for thousands of years. Botryoidal Malachite: Close-up of botryoidal malachite in a seafoam green color from Bisbee, Arizona. This view spans an area of the specimen about 5 millimeters wide and high. Specimen and photo by Arkenstone / www.iRocks.com . Where Does Malachite Form? Malachite is a mineral that forms at shallow depths within the Earth, in the oxidizing zone above copper deposits. It precipitates from descending solutions in fractures, caverns, cavities, and the intergranular spaces of porous rock. It often forms within limestone where a subsurface chemical environment favorable for the formation of carbonate minerals can occur. Associated minerals include azurite , bornite , calcite , chalcopyrite , copper , cuprite , and a variety of iron oxides. Some of the first malachite deposits to be exploited were located in Egypt and Israel. Over 4000 years ago, they were mined and used to produce copper. Material from these deposits was also used to produce gemstones, sculptures, and pigments. Several large deposits in the Ural Mountains of Russia were aggressively mined, and they supplied abundant gem and sculptural material in the 1800s. Very little is produced from these deposits today. Much of the malachite entering the lapidary market today is from deposits in the Democratic Republic of the Congo. Smaller amounts are produced in Australia, France, and Arizona. Stalactitic malachite: A specimen of stalactitic malachite from the Kasompi Mine, Democratic Republic of the Congo. The specimen is approximately 21 x 16 x 12 centimeters in size. Specimen and photo by Arkenstone / www.iRocks.com . Physical Properties of Malachite A minor ore of copper. Gemstones, small sculptures, pigment. Physical Properties of Malachite Malachite's most striking physical property is its green color. All specimens of the mineral are green and range from a pastel green, to a bright green, to an extremely dark green that is almost black. It is typically found as stalactites and botryoidal coatings on the surfaces of underground cavities - similar to the deposits of calcite found in caves. When these materials are cut into slabs and pieces, the sawn surfaces often exhibit banding and eyes that are similar to agate . Malachite is rarely found as a crystal, but when found, the crystals are usually acicular to tabular in shape. The crystals are bright green in color, translucent, with a vitreous to adamantine luster. Non-crystalline specimens are opaque, usually with a dull to earthy luster. Malachite is a copper mineral, and that gives malachite a high specific gravity that ranges from 3.6 to 4.0. This property is so striking for a green mineral that malachite is easy to identify. Malachite is one of a small number of green minerals that produces effervescence in contact with cold, dilute hydrochloric acid . It

What is the term for a fold of the Earth's crust in which the layers of rock dip inwards?

10(l) Crustal Deformation Processes: Folding and Faulting CHAPTER 10: Introduction to the Lithosphere   (l). Crustal Deformation Processes: Folding and Faulting The topographic map illustrated in Figure 10l-1 suggests that the Earth's surface has been deformed. This deformation is the result of forces that are strong enough to move ocean sediments to an eleveation many thousands meters above sea level. In previous lectures, we have discovered that this displacement of rock can be caused by tectonic plate movement and subduction , volcanic activity , and intrusive igneous activity . Figure 10l-1: Topographic relief of the Earth's terrestrial surface and ocean basins. Ocean trenches and the ocean floor have the lowest elevations on the image and are colored dark blue. Elevation is indicated by color. The legend below shows the relationship between color and elevation. (Source: National Geophysical Data Center , National Oceanic and Atmospheric Administration).   Deformation of rock involves changes in the shape and/or volume of these substances. Changes in shape and volume occur when stress and strain causes rock to buckle and fracture or crumple into folds. A fold can be defined as a bend in rock that is the response to compressional forces. Folds are most visible in rocks that contain layering. For plastic deformation of rock to occur a number of conditions must be met, including: The rock material must have the ability to deform under pressure and heat. The higher the temperature of the rock the more plastic it becomes. Pressure must not exceed the internal strength of the rock. If it does, fracturing occurs. Deformation must be applied slowly. A number of different folds have been recognized and classified by geologists. The simplest type of fold is called a monocline (Figure 10i-2). This fold involves a slight bend in otherwise parallel layers of rock. Figure 10l-2: Monocline fold.   An anticline is a convex up fold in rock that resembles an arch like structure with the rock beds (or limbs) dipping way from the center of the structure (Figure 10l-3). Figure 10l-3: Anticline fold. Note how the rock layers dip away from the center of the fold are roughly symmetrical.   A syncline is a fold where the rock layers are warped downward (Figure 10l-4 and 10l-5). Both anticlines and synclines are the result of compressional stress. Figure 10l-4: Syncline fold. Note how the rock layers dip toward the center of the fold and are roughly symmetrical.   Figure 10l-5: Synclinal folds in bedrock, near Saint-Godard-de-Lejeune, Canada. (Source: Natural Resources Canada - Terrain Sciences Division - Canadian Landscapes ).   More complex fold types can develop in situations where lateral pressures become greater. The greater pressure results in anticlines and synclines that are

Which clouds only occur above 10,000 meters?

Clouds - Metlink Teaching Weather and Climate Clouds Cirriform clouds   The nature of clouds A classification of clouds was introduced by Luke Howard (1772-1864) who used Latin words to describe their characteristics. Cirrus – a tuft or filament (e.g. of hair) Cumulus – a heap or pile Stratus – a layer Nimbus – rain bearing There are now ten basic cloud types with names based on combinations of these words (the word ‘alto’, meaning high but now used to denote medium-level cloud, is also used). C.S. Broomfield (© Crown Copyright) Clouds form when moist air is cooled to such an extent that it becomes saturated. The main mechanism for cooling air is to force it to rise. As air rises it expands – because the pressure decreases with height in the atmosphere – and this causes it to cool. Eventually it may become saturated and the water vapour then condenses into tiny water droplets, similar in size to those found in fog, and forms cloud. If the temperature falls below about minus 20 °C, many of the cloud droplets will have frozen so that the cloud is mainly composed of ice crystals. The main ways in which air rises to form cloud Rapid local ascent when heated air at the earth’s surface rises in the form of thermal currents (convection). Slow, widespread, mass ascent where warm moist air is forced to rise above cold air. The region between warm and cold air is called a ‘front’. Upward motion associated with turbulent eddies resulting from the frictional effect of the earth’s surface. Air forced to rise over a barrier of mountains or hills. The first of these tends to produce cumulus-type clouds, whereas the next two usually produce layered clouds. The last can produce either cumulus-type cloud or layered cloud depending upon the state of the atmosphere. The range of ways in which clouds can be formed and the variable nature of the atmosphere give rise to the enormous variety of shapes, sizes and textures of clouds. Types of cloud The ten main types of cloud can be separated into three broad categories according to the height of their base above the ground: high clouds, medium clouds and low clouds. High clouds are usually composed solely of ice crystals and have a base between 18,000 and 45,000 feet (5,500 and 14,000 metres). Cirrus – white filaments Cirrocumulus – small rippled elements Cirrostratus – transparent sheet, often with a halo Medium clouds are usually composed of water droplets or a mixture of water droplets and ice crystals, and have a base between 6,500 and 18,000 feet (2,000 and 5,500 metres). Altocumulus – layered, rippled elements, generally white with some shading Altostratus – thin layer, grey, allows sun to appear as if through ground glass Nimbostratus – thick layer, low base, dark. Rain or snow falling from it may sometimes be heavy Low clouds are usually composed of water droplets – though cumulonimbus clouds include ice crystals – and have a base below 6,500 feet (2,000 metres). Stratocumulus – layered, series of rounded rolls, generally white with some shading Stratus – layered, uniform base, grey Cumulus – individual cells, vertical rolls or towers, flat base Cumulonimbus – large cauliflower-shaped towers, often ‘anvil tops’, sometimes giving thunderstorms or showers of rain or snow Most of the main cloud types can be subdivided further on the basis of shape, structure and degree of transparency. Cumulus Cumulus clouds are often said to look like lumps of cotton wool. With a stiff breeze, they march steadily across the sky; their speed of movement gives a clue to their low altitude. Cumulus clouds occasionally produce light showers of rain or snow. © Steve Jebson © Steve Jebson Typically, the base of cumulus clouds will be about 2,000 feet (600 metres) above ground in winter, and perhaps 4,000 feet (1,200 metres) or more on a summer afternoon. Individual clouds are often short-lived, lasting only about 15 minutes. They tend to form as the ground heats up during the day and become less frequent as the sun’s heat wanes towards evening. The cause of small cumulus clouds is usually convection. Heat from t

Which gas in the atmosphere can be turned into fertilizer by some microbes?

Fertilizer use responsible for increase in nitrous oxide in atmosphere | Berkeley News Fertilizer use responsible for increase in nitrous oxide in atmosphere By Robert Sanders , Media relations | April 2, 2012 Robert Sanders University of California, Berkeley, chemists have found a smoking gun proving that increased fertilizer use over the past 50 years is responsible for a dramatic rise in atmospheric nitrous oxide, which is a major greenhouse gas contributing to global climate change. The Cape Grim Baseline Air Pollution Station in Tasmania, where air samples have been collected since 1978. These samples show a long-term trend in isotopic composition that confirms that nitrogen-based fertilizer is largely responsible for the 20 percent increase in atmospheric nitrous oxide since the Industrial Revolution. Photo courtesy of CSIRO. Climate scientists have assumed that the cause of the increased nitrous oxide was nitrogen-based fertilizer, which stimulates microbes in the soil to convert nitrogen to nitrous oxide at a faster rate than normal. The new study, reported in the April issue of the journal Nature Geoscience, uses nitrogen isotope data to identify the unmistakable fingerprint of fertilizer use in archived air samples from Antarctica and Tasmania. “Our study is the first to show empirically from the data at hand alone that the nitrogen isotope ratio in the atmosphere and how it has changed over time is a fingerprint of fertilizer use,” said study leader Kristie Boering, a UC Berkeley professor of chemistry and of earth and planetary science. “We are not vilifying fertilizer. We can’t just stop using fertilizer,” she added. “But we hope this study will contribute to changes in fertilizer use and agricultural practices that will help to mitigate the release of nitrous oxide into the atmosphere.” Since the year 1750, nitrous oxide levels have risen 20 percent – from below 270 parts per billion (ppb) to more than 320 ppb. After carbon dioxide and methane, nitrous oxide (N2O) is the most potent greenhouse gas, trapping heat and contributing to global warming. It also destroys stratospheric ozone, which protects the planet from harmful ultraviolet rays. Not surprisingly, a steep ramp-up in atmospheric nitrous oxide coincided with the green revolution that increased dramatically in the 1960s, when inexpensive, synthetic fertilizer and other developments boosted food production worldwide, feeding a burgeoning global population. Tracking the origin of nitrous oxide in the atmosphere, however, is difficult because a molecule from a fertilized field looks identical to one from a natural forest or the ocean if you only measure total concentration. But a quirk of microbial metabolism affects the isotope ratio of the nitrogen the N2O microbes give off, producing a telltale fingerprint that can be detected with sensitive techniques. Archived air from Cape Grim Boering and her colleagues, including former UC Berkeley graduate students Sunyoung Park and Phillip Croteau, obtained air samples from Antarctic ice, called firn air, dating from 1940 to 2005, and from an atmospheric monitoring station at Cape Grim, Tasmania, which has archived air back to 1978. Law Dome, Antarctica. Air trapped in the consolidated snow from this region provides historical air samples going back to 1940. Analysis of N2O levels in the Cape Grim air samples revealed a seasonal cycle, which has been known before. But isotopic measurements by a very sensitive isotope ratio mass spectrometer also displayed a seasonal cycle, which had not been observed before. At Cape Grim, the isotopes show that the seasonal cycle is due both to the circulation of air returning from the stratosphere, where N2O is destroyed after an average lifetime of 120 years, and to seasonal changes in the ocean, most likely upwelling that releases more N2O at some times of year than at others. “The fact that the isotopic composition of N2O shows a coherent signal in space and time is exciting, because now you have a way to differentiate agricultural N2O from natural ocean N2O from Amazon f

Which layer of the Earth is believed to be formed of molten iron and nickel?

Layers of the Earth Layers of the Earth   The earth is made up of layers (crust, mantle, outer core, and inner core).   Each one has a unique make-up to it. Crust  This is the outer layer of the Earth about 10 miles or so thick. Mostly made up of rock and loose material.  The crust found underneath continents is 3 times thicker than the crust underneath the oceans. Mantle The next layer beneath the crust is called the mantle.  It extends to a depth of approximately 1,800 miles and is made of a thick solid rocky substance that represents about 85% of the total weight and mass of the Earth. The first 50 miles of the mantle are believed to consist of very hard rigid rock. The next 150 miles or so is believed to be super-heated solid rock. Below that for the next several hundred miles, the Earth mantle is once again made up of very solid and sturdy rock materials. Outer Core Traveling deeper within the Earth, we next would encounter the Earth’s outer core, which extends to a depth of around 3000 miles beneath the surface. It is believed that this outer core is made up of super-heated liquid molten lava. This lava is believed to be mostly iron, and nickel. Inner Core Finally, we would reach the Earth’s inner core. The inner core extends another 900 miles inward towards the center of the Earth. It is believed that this inner core is a solid ball of mostly iron, and nickel. The mantle is made of much denser, thicker material, because of this the plates "float" on it like oil floats on water.  Many geologists believe that the mantle "flows" because of convection currents. Convection Currents These currents are caused by the very hot material rising, cooling, and sinking over and over again.  The next time you heat anything like soup or pudding in a pan you can watch the convection currents move in the liquid. When the convection currents flow in the mantle they also move the crust. The crust gets a free ride with these currents. A conveyor belt in a factory moves boxes like the convection currents in the mantle moves the plates of the Earth. Magma The first question this raises is: what exactly is this "material from the inside"? On our planet, it's magma, fluid molten rock. This material is partially liquid, partially solid and partially gaseous. Radiation

What is the collective noun for rhinoceri?

What Is a Group of Snakes Called? What Is a Group of Snakes Called? Tweet A group of snakes is generally called a bed, den, pit or nest, but a group of rattlesnakes is referred to as a rhumba or rumba. It's not entirely clear why it is called a rhumba, but the word comes from a Cuban Spanish term, rumba, which originally meant "party" or "carousel." Terms such as "bed" or "rhumba" are known as collective nouns when they refer to groups of animals. More collective nouns for animal groups: A group of monkeys is often called a tribe or troop, but it can also be called a shrewdness of monkeys. Groups of baboons specifically can be called a flange or congress of baboons, and groups of chimpanzees can be called a harem of chimpanzees. Perhaps appropriately, a group of cockroaches is called an intrusion of cockroaches. A group of rats is often called a pack, but it also can be called a mischief. Crows also have particularly negative collective nouns, including an unkindness of crows, as well as a congress, a conspiracy, a parliament and a murder of crows. Doves have a more positive group of names, including a cote of doves and a piteousness of doves. A group of ants can be called a bike of ants, and a group of bees can be called a grist of bees. Groups of alligators or crocodiles are called congregations, and groups of Komodo dragons are called banks. Both a group of hippopotami and a group of rhinoceri can be called a crash. A group of hippopotami also can be called a bloat. Follow wiseGEEK:

What type of rock is formed by the rapid cooling of molten lava?

How is obsidian formed? | Reference.com How is obsidian formed? A: Quick Answer Obsidian is formed by rapidly cooling molten rock or lava. Obsidian is also called volcanic glass, and it is considered a mineraloid. Full Answer Examples of the rapid cooling that forms obsidian are lava oozing into a body of water, or lava splashing against something and bouncing into the air. Most obsidian is black; however, it can also be found in other colors. Scientists believe the colors come from other elements mixing in with the molten rock just before the rapid cooling occurs. Most obsidian found is from volcanic eruptions that occurred within the past few million years. That is because older obsidian has most likely shattered into dust over time, as stated by geology.com.

What name is given to the rock formations used as a source of water?

USGS Water Science Glossary of Terms A | B | C | D | E | F | G | H | I | K | L | M | N | O | P | R | S | T | U | V | W | X | Y A acequia--acequias are gravity-driven waterways, similar in concept to a flume. Most are simple ditches with dirt banks, but they can be lined with concrete. They were important forms of irrigation in the development of agriculture in the American Southwest. The proliferation of cotton, pecans and green chile as major agricultural staples owe their progress to the acequia system. acid--a substance that has a pH of less than 7, which is neutral. Specifically, an acid has more free hydrogen ions (H+) than hydroxyl ions (OH-). acre-foot (acre-ft)--the volume of water required to cover 1 acre of land (43,560 square feet) to a depth of 1 foot. Equal to 325,851 gallons or 1,233 cubic meters. alkaline--sometimes water or soils contain an amount of alkali (strongly basic) substances sufficient to raise the pH value above 7.0 and be harmful to the growth of crops. alkalinity--the capacity of water for neutralizing an acid solution. alluvium--deposits of clay, silt, sand, gravel, or other particulate material that has been deposited by a stream or other body of running water in a streambed, on a flood plain, on a delta, or at the base of a mountain. appropriation doctrine--the system for allocating water to private individuals used in most Western states. The doctrine of Prior Appropriation was in common use throughout the arid west as early settlers and miners began to develop the land. The prior appropriation doctrine is based on the concept of "First in Time, First in Right." The first person to take a quantity of water and put it to Beneficial Use has a higher priority of right than a subsequent user. Under drought conditions, higher priority users are satisfied before junior users receive water. Appropriative rights can be lost through nonuse; they can also be sold or transferred apart from the land. Contrasts with Riparian Water Rights. aquaculture--farming of plants and animals that live in water, such as fish, shellfish, and algae. aqueduct--a pipe, conduit, or channel designed to transport water from a remote source, usually by gravity. aquifer--a geologic formation(s) that is water bearing. A geological formation or structure that stores and/or transmits water, such as to wells and springs. Use of the term is usually restricted to those water-bearing formations capable of yielding water in sufficient quantity to constitute a usable supply for people's uses. aquifer (confined)--soil or rock below the land surface that is saturated with water. There are layers of impermeable material both above and below it and it is under pressure so that when the aquifer is penetrated by a well, the water will rise above the top of the aquifer. aquifer (unconfined)--an aquifer whose upper water surface (water table) is at atmospheric pressure, and thus is able to rise and fall. artesian water--groundwater that is under pressure when tapped by a well and is able to rise above the level at which it is first encountered. It may or may not flow out at ground level. The pressure in such an aquifer commonly is called artesian pressure, and the formation containing artesian water is an artesian aquifer or confined aquifer. See flowing well artificial recharge--an process where water is put back into groundwater storage from surface-water supplies such as irrigation, or induced infiltration from streams or wells. B base flow--sustained flow of a stream in the absence of direct runoff. It includes natural and human-induced streamflows. Natural base flow is sustained largely by groundwater discharges. base--a substance that has a pH of more than 7, which is neutral. A base has less free hydrogen ions (H+) than hydroxyl ions (OH-). bedrock--the solid rock beneath the soil and superficial rock. A general term for solid rock that lies beneath soil, loose sediments, or other unconsolidated material. C capillary action--the means by which liquid moves through the porous spaces in a solid, such as soil, plant roots, and the cap

How long does it take for the Earth to spin once on its axis?

BBC - Schools Science Clips - Earth, sun and moon Offline lesson plan Offline lesson plan Objectives Understand that it is the Earth that moves, not the Sun, and the Earth spins on its axis once every 24 hours Know that it is daytime in the part of the Earth facing the Sun and night-time in the part of the Earth away from the Sun     England: Key Stage 2, Science, Sc4 4c Wales: Key Stage 2, Physical processes 4.4 Northern Ireland: Key Stage 3, Physical processes, Earth in space, b Scotland: 5-14 Guidelines, Science, Earth in space, Level B     Copies of the Earth, Sun and Moon worksheet printed from the Science Clips website Globe, light source (e.g. overhead projector light)     Teaching activities Introduction Ask a child to act as the Sun. Explain that the Sun is at the centre of the Solar System. Ask another child to act as the Earth and show how the Earth orbits around the Sun. Then ask the 'the Earth' to spin as it orbits the Sun. Does anyone know how long it takes for the Earth to spin once on its own axis? Activitives Set up the globe and the light so they are level and the light is shining on the globe. Explain to the children that the light represents the Sun, and the globe represents the Earth. How much of the Earth is in light and how much is in shadow? In which half would it be night-time and in which half would it be daytime? Locate the UK on the globe. Turn the globe so the UK is directly opposite the light, in shadow. Is it daytime or night-time in the UK? Explain that it is precisely midnight. Rotate the globe anticlockwise and stop where the change from darkness to light occurs. What would we be experiencing in the UK now? What time would it be? Continue to rotate slowly. Stop when the UK faces the light beam directly. What time would it be now in the UK (midday)? Slowly continue to rotate. Stop where the change from light to darkness occurs. What we would be experiencing in the UK now? What time would it be? Continue to rotate slowly until the UK is facing directly away from the light again. What time is it now? How long does it take for the Earth to complete one spin? Ensure children understand that one complete turn takes 24 hours (one day). Hand out copies of the worksheet. Let children complete it independently, shading in each diagram where it is night on Earth. Plenary Review the worksheet. Discuss how it doesn't appear to us on Earth that the Earth is moving, but it appears that the Sun moves and it appears to rise and set in the sky.     Extension Fasten a matchstick to the UK on the globe with a piece of blu-tack. Ask children to make observations of the shadow as they rotate the Earth through a day.     Suggested homework Ask children to calculate, using their age, the answers to the following questions. How many times have they rotated with the Earth?

What is a very hard, naturally-occurring mineral, of which ruby and sapphire are gem quality varieties?

Ruby and Sapphire: Gems of the Mineral Corundum Home » Gemstones » Ruby and Sapphire Ruby and Sapphire Ruby and sapphire have the same chemical composition and crystal structure - they are both varieties of the mineral corundum Rubies: The most desired variety of corundum is the ruby. The red color is produced by trace amounts of chromium in the mineral. These two beautiful rubies were mined in Madagascar. The one on the left is a 7 x 5 millimeter octagon that weighs about 1.32 carats. The one on the right is an 8 x 6 millimeter oval that weighs about 1.34 carats. Although Asia has been the traditional source of gem corundum for over one thousand years, Africa is poised to become a new primary source. Ruby, Sapphire, and Fancy Sapphire Most people don't realize that ruby and sapphire are both gems of the mineral corundum . Both of these gems have the same chemical composition and the same mineral structure. Trace amounts of impurities determine if a gem corundum will be a brilliant red ruby or a beautiful blue sapphire. It is surprising that "impurities" can produce such wonderful results! Red and blue are just two of the many colors found in gem corundums. Trace amounts of other elements can produce brilliant yellow, orange, green, and purple gems. Red corundums are known as "rubies," blue corundums are known as "sapphires," and corundums of any other color are known as " fancy sapphires ." Corundum produces gems in a spectrum of colors. Related:   Corundum: Mineral Summary What Makes a Ruby? Some gem-quality corundum contains trace amounts of chromium. A very small amount of chromium gives corundum a pink color. Larger amounts of chromium increase the color saturation of the stone and produce a gem with a deeper red color. To be considered a "ruby," a corundum should have a color between orangey red and a slightly purplish red. The most desirable color is a pure vibrant red. Very few specimens of corundum have a natural color within the range required for a ruby. Very few also have the clarity required to produce a nice faceted stone. Long ago, people who prepared gem materials for cutting discovered that heating rubies under controlled conditions can intensify their color. Heating can also cause inclusions to become less visible and improve the clarity of a gem. Most rubies in the market today have been heated to improve their color and clarity. Many of them have had other treatments to improve their appearance. These treatments are normal and expected in the gem trade, but a seller should disclose them to a buyer in advance of a sale. Montana sapphire: The most widely known sapphire locality in North America is Yogo Gulch, Montana, famous for producing deep blue sapphires of excellent quality. Creative Commons photo of a gem from Barnes Jewelry, Helena, Montana, by Montanabw. Corundum as ruby, sapphire, and fancy sapphire: Gem-quality corundum is a highly prized and valuable material. When it is bright red in color, it is called "ruby." When it is deep blue, it is called "sapphire." Gem-quality corundum of any other color is called "fancy sapphire." All of the stones in this photo were mined in Africa. What Makes a Sapphire? Trace amounts of iron and titanium can develop a blue color in corundum. Blue corundums are known as "sapphires." The name "sapphire" is used for corundums that range from light blue to dark blue in color. The blue can range from a violetish blue to a greenish blue. Stones in the middle of this range, with a rich blue color, are the most desirable. Gem-quality corundum occurs in a wide range of other colors, including pink, purple, orange, yellow, and green. These stones are known as "fancy sapphires." It is surprising that a single mineral can produce gemstones of so many different colors. When the color of a sapphire is any color other than blue, the color should be used as a preceding adjective to describe the stone. For example, pink sapphire, yellow sapphire, or green sapphire. Used alone, the word "sapphire" refers only to blue corundum. The color and clarity of blue

Corundum is a mineral oxide of which metal?

oxide mineral | Britannica.com Oxide mineral maghemite Oxide mineral, any naturally occurring inorganic compound with a structure based on close-packed oxygen atoms in which smaller, positively charged metal or other ions occur in interstices. Oxides are distinguished from other oxygen-bearing compounds such as the silicates, borates, and carbonates, which have a readily definable group containing oxygen atoms covalently bonded to an atom of another element. Oxide minerals brown to indigo blue and black; also variable adamantine to metallic adamantine white to pale green, gray, or blue waxy to vitreous reddish or yellowish brown to brownish black adamantine to metallic adamantine, usually splendent 6–7 iron black to brownish black; often with iridescent tarnish 6–6½ 5.2 (columbite) to 8.0 (tantalite) corundum red (ruby); blue (sapphire); also variable adamantine to vitreous white, grayish white, colourless; variable brilliant vitreous brilliant submetallic to greasy or vitreous 5½–6½ white; grayish, greenish, reddish white vitreous blackish brown (crystals); yellowish or reddish brown adamantine-metallic steel gray; dull to bright red metallic or submetallic to dull 5–6 ruby red to reddish brown submetallic dark steel gray to iron black submetallic colourless to grayish; also green, yellow, or black vitreous perovskite (often containing rare earths) black; grayish or brownish black; reddish brown to yellow adamantine to metallic iron black to dark steel gray submetallic to dull brown to black (pyro); pale yellow to brown (micro) vitreous or resinous light steel gray to iron black metallic reddish brown to red; variable metallic adamantine steel or iron gray to black metallic dark gray to brownish black and bluish hornlike to submetallic steel to velvet black; grayish, greenish submetallic to greasy or dull 5–6 6.5–8.5 (massive); 8.0–10.0 (crystals) name refractive indices or polished section data crystal system disseminated or in pisolitic aggregates one very good cleavage only as crystals, usually tabular subconchoidal to uneven fracture tabular crystals; platy aggregates; fibrous or foliated massive one perfect cleavage repeatedly twinned crystals; crusts and concretions one imperfect cleavage tabular or prismatic, commonly twinned, crystals one distinct cleavage prismatic crystals, often in large groups; massive one distinct cleavage pyramidal or barrel-shaped crystals; large blocks; rounded grains no cleavage; uneven to conchoidal fracture omega = 1.767–1.772 octahedral, cubic, or capillary crystals; granular or earthy massive conchoidal to uneven fracture bluish white; anomalously anisotropic and plechroic isometric rosy brown-white; strongly anisotropic; distinctly pleochroic hexagonal thin, platy crystals; scaly massive; disseminated one perfect cleavage, one less so alpha = 1.682–1.706 tabular crystals; crusts and coatings; compact earthy one perfect cleavage one perfect cleavage, one less so alpha = 2.260–2.275 tabular crystals; rosettes; columnar or fibrous massive; earthy massive; reniform masses no cleavage anisotropic; weakly pleochroic; often shows lamellar twinning hexagonal thick, tabular crystals; compact massive; grains no cleavage; conchoidal fracture n = about 2.7 grayish white; anisotropic hexagonal flattened scales; isolated rounded crystals; massive one perfect cleavage, one less so alpha = 1.94 gray-white; strongly anisotropic and pleochroic orthorhombic crusts; alteration product on massicot one cleavage prismatic crystals, often in bundles; fibrous massive one very perfect cleavage, two less so alpha = 2.25 brownish gray-white; anisotropic; weakly pleochroic monoclinic irregular, rounded grains; octahedral crystals one perfect cleavage perovskite (often containing rare earths) cubic crystals massive; crusts; stalactites; earthy masses orthorhombic columnar or fibrous massive; coatings and concretions one perfect cleavage cream-white; distinctly anisotropic; very weakly pleochroic tetragonal slender to capillary prismatic crystals; granular massive; as inclusions, often oriented one distinct clea

What is the name of the force which keeps the planets in orbit around the sun?

How do the planets stay in orbit around the sun? | Cool Cosmos   How do the planets stay in orbit around the sun? The Solar System was formed from a rotating cloud of gas and dust which spun around a newly forming star, our Sun, at its center. The planets all formed from this spinning disk-shaped cloud, and continued this rotating course around the Sun after they were formed. The gravity of the Sun keeps the planets in their orbits. They stay in their orbits because there is no other force in the Solar System which can stop them. Continue the conversation on

Which planet is named after the Roman god of war?

Mars is Named After... - Universe Today   Universe Today by Jerry Coffey Mars is named after the Roman god of war. Many believe that ancient peoples associated Mars with bloodshed and war because of its red color. The Romans were not the only society to associate the planet with bloodshed. The ancient Babylonians called it Nergal, after their god of fire, war, and destruction. In keeping with the planet’s association with the god Mars, its symbol is a circle with an arrow pointing outwards from its right corner. This is meant to represent Mar’s shield and spear. That information is not nearly enough to satisfy anyone’s interest in the Red Planet, so here are a few interesting facts about Mars and its environs. The largest mountain in the Solar System is on Mars. Olympus Mons is 27 km tall. It is a shield volcano that was able to erupt for million of years because Mars does not have tectonic plate movement. This allowed the same volcanic hotspot to erupt undisturbed until the giant mountain was formed. The chemical symbol for iron is the same as the astronomical symbol for Mars. This is fitting, since the planet gets its reddish appearance from the iron oxide in the dust on its surface. A year on Mars lasts 686.98 Earth days or 1.88 Earth years. There are four seasons throughout the year like here on Earth, but each season is longer than a typical Earth season. Mars is full of water. Not liquid water like we see here on Earth, but water ice under the surface and at the bottom of craters. There is even evidence that there may be ice inside of caves on the Martian surface. These deposits are safe from the solar radiation that bombards the surface, so they are able to stay in place. Mars does not have a magnetic field at this time, but spacecraft have detected residual magnetism in rocks on the surface. That would suggest an active magnetic field millions, if not billions, of years ago. Scientist believe that the core of Mars has become too solid to rotate and is no longer capable of generating a dynamo effect. A dynamo effect is essential in producing a magnetic field. These are just a few of the interesting facts beyond who Mars is named after. Pay special attention to information generated by the Mars Express spacecraft. It has turned up a great deal of interesting data on, and under, the Martian surface. In case you’re wondering, here’s how Jupiter got its name . Here’s some historical information on Mars, the god of war, and more on Ares , the Greek version of Mars. Finally, if you’d like to learn more about Mars in general, we have done several podcast episodes about the Red Planet at Astronomy Cast. Episode 52: Mars , and Episode 91: The Search for Water on Mars . Sources:

Which planet is closest to the sun?

Solar System Planets: Order of the 8 (or 9) Planets Solar System Planets: Order of the 8 (or 9) Planets By Robert Roy Britt | January 22, 2016 12:35pm ET MORE The planets of the solar system as depicted by a NASA computer illustration. Orbits and sizes are not shown to scale. Credit: NASA Ever since the discovery of Pluto in 1930, kids grew up learning about the nine planets of our solar system. That all changed starting in the late 1990s, when astronomers began to argue about whether Pluto was a planet. In a highly controversial decision , the International Astronomical Union ultimately decided in 2006 to call Pluto a “dwarf planet,” reducing the list of “real planets” in our solar system to eight.  However, astronomers are now hunting for another planet in our solar system, a true ninth planet , after evidence of its existence was unveiled on Jan. 20, 2016. The so-called "Planet Nine," as scientists are calling it, is about 10 times the mass of Earth and 5,000 times the mass of Pluto. [ Solar System Pictures: A Photo Tour ] If you insist on including Pluto , then that world would come after Neptune on the list; Pluto is truly way out there, and on a wildly tilted, elliptical orbit (two of the several reasons it got demoted). Interestingly, Pluto used to be the eighth planet, actually. More on that below. Terrestrial planets The inner four worlds are called “ terrestrial planets ,” because, like Earth, their surfaces are all rocky. Pluto, too, has a solid surface (and a very frozen one) but has never been grouped with the four terrestrials. Jovian planets The four large outer worlds — Jupiter, Saturn, Uranus, and Neptune — are known as the “Jovian planets” (meaning “Jupiter-like”) because they are all huge compared to the terrestrial planets, and because they are gaseous in nature rather than having rocky surfaces (though some or all of them may have solid cores, astronomers say). According to NASA , "two of the outer planets beyond the orbit of Mars — Jupiter and Saturn — are known as gas giants; the more distant Uranus and Neptune are called ice giants." This is because, while the first two are dominated by gas, while the last two have more ice. All four contain mostly hydrogen and helium. Dwarf planets The  IAU definition of a full-fledged planet goes like this: A body that circles the sun without being some other object's satellite, is large enough to be rounded by its own gravity (but not so big that it begins to undergo nuclear fusion, like a star) and has "cleared its neighborhood" of most other orbiting bodies. Yeah, that’s a mouthful. The problem for Pluto, besides its small size and offbeat orbit, is that it shares its space with lots of other objects in the Kuiper Belt , beyond Neptune. Still, the demotion of Pluto remains controversial . The IAU planet definition puts other small, round worlds in the dwarf planet category, including the Kuiper Belt objects Eris , Haumea , and Makemake . Also now a dwarf planet is Ceres , a round object in the Asteroid Belt between Mars and Jupiter. Ceres was actually considered a planet when discovered in 1801 and then later deemed to be an asteroid. Some astronomers like to consider Ceres as a 10th planet (not to be confused with Nibiru or Planet X ), but that line of thinking opens up the possibility of there being 13 planets, with more bound to be discovered. The planets Below is a brief overview of the eight primary planets in our solar system , in order from the inner solar system outward: Mercury The closest planet to the sun, Mercury is only a bit larger than Earth's moon. Its day side is scorched by the sun and can reach 840 degrees Fahrenheit (450 Celsius), but on the night side, temperatures drop to hundreds of degrees below freezing. Mercury has virtually no atmosphere to absorb meteor impacts, so its surface is pockmarked with craters, just like the moon. Over its four-year mission, NASA's MESSENGER spacecraft has revealed views of the planet that have challenged astronomers' expectations. Discovery: Known to the ancients and visible to the naked eye Named for: M

Which two planets take less time than Earth to orbit the sun?

Planets | Scholastic Grades 3–5, 6–8, 9–12 The following questions were answered by astronomer Dr. Cathy Imhoff of the Space Telescope Science Institute. Do all the planets have seasons? What causes seasons? Earth is tilted with respect to its orbit around the sun. So when our North Pole is tilted toward the sun, we get summer in the Northern Hemisphere (winter in the south). When the South Pole is tilted toward the sun, we get winter. So if a planet is tilted with respect to its orbit around the sun, it should have seasons. Here are the numbers that I was able to find this morning (as of September 1994) Venus — 23 degrees tilt, Earth — 23.5, Mars — 24, Jupiter — 3, Saturn — 27, Uranus — 98, Neptune — 29. But you can see that most of the planets have tilts like Earth, so they must have seasons. As I noted above, we definitely see seasons on Mars. In winter its ice caps grow, in summer they shrink. Jupiter has very little tilt, so it doesn't experience noticeable seasons. But Neptune is turned all the way over on its side! It must have very strange seasons! How did the planets get their names? Five of the planets were known to people thousands of years ago. They are bright enough to be seen with the naked eye and they move with respect to the stars. The name planet comes from the Greek word for "wanderer." I'm sure that people in different lands had various names for them, but the names we use come from the ancient Greeks and Romans. They named the planets for some of their gods. Mercury was the Roman god of commerce and cunning, and also messenger to the gods. Venus was the goddess of love. Mars was the god of war. Jupiter was the chief god. Saturn was the god of agriculture. When the next planet was found by Sir William Herschel in 1781, there was quite a debate about what to name it. Finally everyone decided to stay with the Roman names from mythology. So the new planet was finally named Uranus, for the father of the Titans. The next planet was named Neptune, for the god of the seas. And Pluto was named for the god of the underworld. Most of the moons and some asteroids are also named from Roman mythology. What was the first planet discovered? Who discovered it? What kind of equipment did they use? Five planets have been known since ancient times — Mercury, Venus, Mars, Jupiter, and Saturn. The first new planet discovered was Uranus. It was discovered by the English astronomer Sir William Herschel in 1781. Herschel was one of the first modern astronomers. His patron was King George III of England (the same King George from the time of the American Revolution!). Herschel wanted to name the planet after King George, but nobody else liked that so they gave it the name Uranus. Herschel and his sister Charlotte (who was an astronomer in her own right) used several reflecting telescopes, some of the first based on a design invented by Sir Isaac Newton. The largest was over 40 feet long and had a mirror 48 inches across. It was held up with a framework of wood, and they had to have helpers move it around using ropes and pulleys. It was the largest telescope in the world until over 100 years later. Which planet was formed first and how was it formed? We think that the planets all formed pretty much at the same time. However the sun probably formed first. The leftover gas and dust remained in a disk around the sun. In this disk, stuff began to clump and form "planetesimals" (pronounced pla-ne-TE-si-mals). These are small rocky bodies, something like asteroids. They crashed into each other and eventually formed the inner planets. At the same time, planetesimals formed the cores of the outer planets Jupiter and Saturn. Because of their strong gravity, they swept up a lot of gas. Uranus and Neptune did this too, but there was less gas around because Jupiter and Saturn got it first. The asteroid belt may be left-over planetesimals that never formed a planet because Jupiter's strong gravity nearby kept it from forming. Are there any living things on any of the planets? So far we know of only one planet with life — Earth! In 1976, we

Which planet has a day which lasts eight months?

How Long Is A Day On The Other Planets Of The Solar System? - Universe Today   Universe Today How Long Is A Day On The Other Planets Of The Solar System? Article Updated: 24 Jan , 2016 by Matt Williams Here on Earth, we tend to take time for granted, never suspected that the increments with which we measure it are actually quite relative. The ways in which we measure our days and years, for example, are actually the result of our planet’s distance from the Sun, the time it takes to orbit, and the time it takes to rotate on its axis. The same is true for the other planets in our Solar System. While we Earthlings count on a day being about 24 hours from sunup to sunup, the length of a single day on another planet is quite different. In some cases, they are very short, while in others, they can last longer than years – sometimes considerably! Let’s go over how time works on other planets and see just how long their days can be, shall we? A Day On Mercury: Mercury is the closest planet to our Sun, ranging from 46,001,200 km at perihelion (closest to the Sun) to 69,816,900 km at aphelion (farthest). Since it takes 58.646 Earth days for Mercury to rotate once on its axis – aka. its sidereal rotation period – this means that it takes just over 58 Earth days for Mercury to experience a single day. However, this is not to say that Mercury experiences two sunrises in just over 58 days. Due to its proximity to the Sun and rapid speed with which it circles it, it takes the equivalent of 175.97 Earth days for the Sun to reappear in the same place in the sky. Hence, while the planet rotates once every 58 Earth days, it is roughly 176 days from one sunrise to the next on Mercury. Images of Mercury’s northern polar region, provided by MESSENGER. Credit: NASA/JPL What’s more, it only takes Mercury 87.969 Earth days to complete a single orbit of the Sun (aka. its orbital period). This means a year on Mercury is the equivalent of about 88 Earth days, which in turn means that a single Mercurian (or Hermian) year lasts just half as long as a Mercurian day. What’s more, Mercury’s northern polar regions are constantly in the shade. This is due to it’s axis being tilted at a mere 0.034° (compared to Earth’s 23.4°), which means that it does not experience extreme seasonal variations where days and nights can last for months depending on the season. On the poles of Mercury, it is always dark and shady. So you could say the poles are in a constant state of twilight. A Day On Venus: Also known as “Earth’s Twin”, Venus is the second closest planet to our Sun – ranging from 107,477,000 km at perihelion to 108,939,000 km at aphelion. Unfortunately, Venus is also the slowest moving planet, a fact which is made evident by looking at its poles. Whereas every other planet in the Solar System has experienced flattening at their poles due to the speed of their spin, Venus has experienced no such flattening. Venus has a rotational velocity of just 6.5 km/h (4.0 mph) – compared to Earth’s rational velocity of 1,670 km/h (1,040 mph) – which leads to a sidereal rotation period of 243.025 days. Technically, it is -243.025 days, since Venus’ rotation is retrograde. This means that Venus. rotates in the direction opposite to its orbital path around the Sun. The planet Venus, as imagined by the Magellan 10 mission. Credit: NASA/JPL So if you were above Venus’ north pole and watched it circle around the Sun, you would see it is moving clockwise, whereas its rotation is counter-clockwise. Nevertheless, this still means that Venus takes over 243 Earth days to rotate once on its axis, which means that many, many days pass between one sunrise and the next. This may seem odd, until you consider that a single Venusian (or Cytherean) year works out to 224.701 Earth days. Yes, Venus takes a little more than 224 days to complete a single orbital period, but over 243 days to experience a single day and night cycle. So basically, a single Venusian day is longer than a Venusian year! Good thing Venus has other things in common With Earth, because it is sure isn’t its diurnal cy

What is the term for a natural satellite?

What does Natural satellite mean? This page provides all possible meanings and translations of the word Natural satellite Freebase(4.60 / 5 votes)Rate this definition: Natural satellite A natural satellite, or moon, is a celestial body that orbits another body, e.g. a planet, which is called its primary. There are 173 known natural satellites orbiting planets in the Solar System, as well as at least eight orbiting IAU-listed dwarf planets. As of January 2012, over 200 minor-planet moons have been discovered. There are 76 known objects in the asteroid belt with satellites, four Jupiter trojans, 39 near-Earth objects, and 14 Mars-crossers. There are also 84 known natural satellites of trans-Neptunian objects. Some 150 additional small bodies have been observed within rings of Saturn, but only a few were tracked long enough to establish orbits. Planets around other stars are likely to have satellites as well, though numerous candidates have been detected to date, none have yet been confirmed. Of the inner planets, Mercury and Venus have no natural satellites; Earth has one large natural satellite, known as the Moon; and Mars has two tiny natural satellites, Phobos and Deimos. The large gas giants have extensive systems of natural satellites, including half a dozen comparable in size to Earth's Moon: the four Galilean moons, Saturn's Titan, and Neptune's Triton. Saturn has an additional six mid-sized natural satellites massive enough to have achieved hydrostatic equilibrium, and Uranus has five. It has been suggested that some satellites may potentially harbour life, though there is currently no direct evidence of life. Numerology The numerical value of Natural satellite in Chaldean Numerology is: 6 Pythagorean Numerology

Who was the first man in space?

First man in space - Apr 12, 1961 - HISTORY.com First man in space Publisher A+E Networks On April 12, 1961, aboard the spacecraft Vostok 1, Soviet cosmonaut Yuri Alekseyevich Gagarin becomes the first human being to travel into space. During the flight, the 27-year-old test pilot and industrial technician also became the first man to orbit the planet, a feat accomplished by his space capsule in 89 minutes. Vostok 1 orbited Earth at a maximum altitude of 187 miles and was guided entirely by an automatic control system. The only statement attributed to Gagarin during his one hour and 48 minutes in space was, “Flight is proceeding normally; I am well.” After his historic feat was announced, the attractive and unassuming Gagarin became an instant worldwide celebrity. He was awarded the Order of Lenin and given the title of Hero of the Soviet Union. Monuments were raised to him across the Soviet Union and streets renamed in his honor. The triumph of the Soviet space program in putting the first man into space was a great blow to the United States, which had scheduled its first space flight for May 1961. Moreover, Gagarin had orbited Earth, a feat that eluded the U.S. space program until February 1962, when astronaut John Glenn made three orbits in Friendship 7. By that time, the Soviet Union had already made another leap ahead in the “space race” with the August 1961 flight of cosmonaut Gherman Titov in Vostok 2. Titov made 17 orbits and spent more than 25 hours in space. To Soviet propagandists, the Soviet conquest of space was evidence of the supremacy of communism over capitalism. However, to those who worked on the Vostok program and earlier on Sputnik (which launched the first satellite into space in 1957), the successes were attributable chiefly to the brilliance of one man: Sergei Pavlovich Korolev. Because of his controversial past, Chief Designer Korolev was unknown in the West and to all but insiders in the USSR until his death in 1966. Born in the Ukraine in 1906, Korolev was part of a scientific team that launched the first Soviet liquid-fueled rocket in 1933. In 1938, his military sponsor fell prey to Soviet leader Joseph Stalin’s purges, and Korolev and his colleagues were also put on trial. Convicted of treason and sabotage, Korolev was sentenced to 10 years in a labor camp. The Soviet authorities came to fear German rocket advances, however, and after only a year Korolev was put in charge of a prison design bureau and ordered to continue his rocketry work. In 1945, Korolev was sent to Germany to learn about the V-2 rocket, which had been used to devastating effect by the Nazis against the British. The Americans had captured the rocket’s designer, Wernher von Braun, who later became head of the U.S. space program, but the Soviets acquired a fair amount of V-2 resources, including rockets, launch facilities, blueprints, and a few German V-2 technicians. By employing this technology and his own considerable engineering talents, by 1954 Korolev had built a rocket that could carry a five-ton nuclear warhead and in 1957 launched the first intercontinental ballistic missile. That year, Korolev’s plan to launch a satellite into space was approved, and on October 4, 1957, Sputnik 1 was fired into Earth’s orbit. It was the first Soviet victory of the space race, and Korolev, still technically a prisoner, was officially rehabilitated. The Soviet space program under Korolev would go on to numerous space firsts in the late 1950s and early ’60s: first animal in orbit, first large scientific satellite, first man, first woman, first three men, first space walk, first spacecraft to impact the moon, first to orbit the moon, first to impact Venus, and first craft to soft-land on the moon. Throughout this time, Korolev remained anonymous, known only as the “Chief Designer.” His dream of sending cosmonauts to the moon eventually ended in failure, primarily because the Soviet lunar program received just one-tenth the funding allocated to America’s successful Apollo lunar landing program. Korolev died in 1966. Upon his death, his i

Which was the first space probe to leave the solar system?

Space Today Online - Voyager spacecraft are leaving the Solar System NASA's Voyager probes carry messages for extraterrestrial civilizations: greetings from humans and whales, some of Earth's greatest music, brainwaves of a woman in love. Click to enlarge NASA artist concept of Voyager 1 and 2 NASA's Voyager 1 spacecraft is the most distant human-made object in the universe. Its twin, Voyager 2, has traveled to more planets than any other in history. The spacecraft twins, Voyager 1 and Voyager 2, were launched by NASA during the summer of 1977 from Cape Canaveral, Florida. Barring any fatal equipment failures, the Voyager twins are likely to survive and relay data from beyond the outer planets for many decades into the 21st century. Today, in a dark, cold, vacant neighborhood at the very edge of our Solar System, NASA's Voyager 1 deep space probe holds the record as the Earth explorer that has traveled farthest from home. Voyager 1 When Voyager I was launched in 1977 to study and photograph the giant outer planets of the Solar System, the robot ship was expected to survive just four years. However, like the battery advertising icon, the Energizer Bunny, the little spacecraft kept on going. For 25 years, the Pioneer 10 spacecraft led the way outbound, pressing the frontiers of exploration, but in 1998 the baton was passed from Pioneer 10 to Voyager 1, according to NASA's Jet Propulsion Laboratory (JPL), Pasadena, California. Voyagers Timeline SOURCES: NASA JPL , STO On Feb. 17, 1998, the Voyager 1 spacecraft cruised beyond the Pioneer 10 spacecraft and become the most distant human-created object in space. At that time, it was 6.5 billion miles from Earth. Pioneer 10 and Voyager 1 are headed in almost opposite directions away from the Sun. The twins, Voyager 1 and 2, opened new vistas for the human race by expanding our knowledge of Jupiter and Saturn. Voyager 2 then extended our great planetary adventure when it flew by Uranus and Neptune, becoming the only spacecraft ever to visit these worlds. (None has ever visited Pluto.) Voyager 1, now the most distant human-made object in the Universe, and Voyager 2, close on its heels, continue their ground-breaking journey with their current mission to study the region in space where the Sun's influence ends and the dark recesses of interstellar space begin. Voyager 1 is almost 70 times farther from the Sun than the Earth. Out there, the Sun is only 1/5,000th as bright as here on Earth. It is extremely cold, and there is little solar energy to keep the probe warm and to provide electrical power. The probe can continue to operate at such great distances from the Sun because it has radioisotope thermal electric generators (RTGs) that create electricity. The fact that the spacecraft is still returning data is a remarkable technical achievement. Voyager flight path. Voyager 1 was launched from Cape Canaveral on Sept. 5, 1977. It flew by Jupiter on March 5, 1979, and then Saturn on Nov. 12, 1980. Because its trajectory was designed to fly close to Saturn's large moon Titan, Voyager 1's path was bent northward by Saturn's gravity. That sent the spacecraft out of the Solar System's ecliptic plane -- the plane in which all the planets, except Pluto, orbit the Sun. On Feb. 17, 1998, Voyager 1 was departing the Solar System at a speed of 39,000 miles per hour. At the same time, Voyager 2 was 5.1 billion miles from Earth and was departing the Solar System at a speed of 35,000 miles per hour. Voyager 2 is heading in the opposite direction of Voyager I and traveling at a slightly slower speed. Pioneer 10 had been launched earlier, on March 2, 1972. Its official mission ended on March 31, 1997. However, NASA's Ames Research Center, Moffett Field, CA, intermittently receives science data from Pioneer as part of a training program for flight controllers. Low power. Voyager 1 was so far from Earth in 1998 that it took 9 hours 36 minutes for a radio signal traveling at the speed of light to reach Earth. Voyager's signal, produced by a 20 watt radio transmitter, is so faint that the amount of

What is almost halfway through its 10-billion-year life, will expand to become a red giant and then shrink to become a white dwarf?

Formation of Planetary Nebulae Home The Not-so-Ordinary Life of a Typical Star Scattered like diamond chips across the Cosmos, stars look deceptively serene to earthbound observers. However, nothing could be farther from true because each one is a creature of unimaginable violence. Constant and unchanging, the nighttime stellar canopy appears essentially the same to us as it did to the ancient Greeks. But, this perception is misleading because, like people, even stars follow a cycle of birth and death. A star, like our Sun, begins its life as a vast cloud of gas and dust drifting among the apparently empty spaces between the stars. These clouds of sparse material are truly immense and often span hundreds or thousands of light years in all directions. Even though they contain fewer atoms than the best vacuum on Earth, the total amount of material in an interstellar cloud, also known as its mass, is truly astronomical. Most of the stuff in one of these clouds is hydrogen, the simplest and most abundant element in the Universe, but they also contain other, more complex, elements, too. For example, the cloud of dust and gas that formed our Sun must have included material from a previous generation star that blew itself apart. We suspect this because our Sun, and all of its planets including Earth, contain heavy elements that could only have been forged in the heart of a larger, long gone star that went supernova. Stars, like factories, create complex elements from hydrogen and release radiation as a by-product of their creation. The life cycle of a typical star like our Sun. Illustration credit: Wikipedia For billions of years interstellar clouds wander more or less aimlessly between their starry relatives until they receive a gravitational nudge, possibly from a nearby exploding star or the close passing of another galaxy. Significantly, once the cloud is pushed, events take on a life of their own and the material begins to contract inward under its own massive weight. As the dust particles and gas molecules move toward the cloud's center, they inevitably begin bumping into each other. Like rubbing your hands together, this generates heat. Stellar womb- am artist's impression of the central region inside an interstellar cloud where gravity is forging new stars. Illustration credit: M. Kornmesser/ESO Over time, these molecular collisions became more frequent. Eventually, the core of the cloud becomes so squeezed by gravity that pressures exceeded billions of atmospheres and temperatures reach over 50 million degrees. At this temperature, hydrogen nuclei collide with such speed, a thermonuclear reaction, known as fusion, is triggered. Fusion is the same process released when a hydrogen bomb is exploded. However, the amount of energy produced by a star is billions of times greater than any man-made nuclear weapon. When fusion commences, hydrogen is converted into the next heaviest element (helium) and a tremendous amount of energy is released in the form of photons. As the photons rush from the core of the cloud, they push back on the inward pressure of gravity, which is still trying to compress the cloud, until an equilibrium is achieved and the cloud's collapse ceases. Eventually the photons escape into space as visible light and other forms of invisible radiation and the star is born. Thus, a star is a balance between the unrelenting inward pull of gravity and the ongoing thermonuclear explosion pushing back from its core. Phase One- Nothing lasts forever Although, most of a star's volume is comprised of hydrogen, hydrogen can only be fused into helium at its core and all stars eventually deplete their central store of hydrogen. Thus, the balance that creates a star is only temporary. For example, although our Sun is supremely important to our existence, it is only an average star, about halfway through its 10 billion year life-cycle. Stars with less mass require less thermonuclear energy at their cores to counter balance the force of gravity, therefore they are cooler and shine for a longer period of time. Converse

Which planet orbits the Sun four times in the time it takes the Earth to go round once?

How Long it Takes for Each Planet to Orbit the Sun How Long it Takes for Each Planet to Orbit the Sun How Long it Takes for Each Planet to Orbit the Sun If one was asked the questions, οΏ½How long is a day?οΏ½ and οΏ½How long is a year?οΏ½ they would probably be very offended by such a simple question. A day is 24 hours, while a year is 365 days long, 366 during a leap year. In the basic sense, this answer would be correct, but the answer really only applies to Earth. On different planets, there are very different times of what constitutes a οΏ½day,οΏ½ which is the time it takes for a planet to complete one turn of its axis and a οΏ½year,οΏ½ which equivocates to the time it takes a planet to completely orbit around the sun. Planets that are closer to the sun do not take as long to complete their orbit and subsequently have shorter years than our planet. Alternatively, planets that are far away, such as Neptune or Saturn, take a very long time to completely orbit around the sun. Interestingly enough however, it seems to be the farther a planet is away from the sun, the faster they can complete a turn of their access. This means that although far reaching planets have longer years, their days are actually shorter than EarthοΏ½s. In terms of the four closest planets to the sun, excluding Earth, it can be seen how distance from the planet effects the time it takes for each planet to orbit the sun. Mercury, the first planet in our solar system can completely orbit around the sun in a mere 88 Earth Days, but nearly takes 60 days to complete a turn of its axis. Venus, which is the closet planet to Earth, takes 224 days to orbit around the sun. Oddly enough Venus takes longer to complete a rotation of its axis, 243 days, than it does to completely orbit the sun. Mars, one of the closest planets to Earth in size takes around 686.97 days to orbit around the earth and has a nearly identical day of 24.3 hours. The last four planets of the sun, demonstrate the immense effect of distance on the time it takes for a planet to rotate around the sun. Jupiter, the solar systemοΏ½s largest planet, takes 4,331.572 days to orbit around the sun, but the fast turning planet only takes 9.8 hours to completely rotate on its axis. Saturn takes more than double the time of Jupiter to orbit the sun with a time of 10,832.33 days, but has nearly an identical time to rotate on its axis with 10.2 hours. Uranus and Neptune are the two farthest planets from the sun and the time it takes for them to orbit around the sun reflects this. Uranus takes 30,7999.09 days to orbit around the sun, which is impressive but cannot compare to the 60,190 days it takes Neptune to complete the same task. However, Uranus and Neptune have comparable rotation times of 17.14 and 16 hours respectively. Next time youοΏ½re asked about how long a year or a day is, make sure to not fall into the boring perspective of only thinking about your planet. Giving the answer that a year on Neptune is more than 60,000 days or a day on Jupiter is less than 10 hours is a lot more interesting.

Which is the largest moon in the solar system?

Jupiter's Moon Ganymede - Universe Today   Universe Today by Matt Williams In 1610, Galileo Galilei looked up at the night sky through a telescope of his own design . Spotting Jupiter, he noted the presence of several “luminous objects” surrounding it, which he initially took for stars. In time, he would notice that these “stars” were orbiting the planet, and realized that they were in fact Jupiter’s moons – which would come to be named Io , Europa , Ganymede and Callisto . Of these, Ganymede is the largest, and boasts many fascinating characteristics. In addition to being the largest moon in the Solar System, it is also larger than even the planet Mercury. It is the only satellite in the Solar System known to possess a magnetosphere, has a thin oxygen atmosphere, and (much like its fellow-moons, Europa and Callisto) is believed to have an interior ocean. Discovery and Naming: Though Chinese astronomical records claim that astronomer Gan De may have spotted a moon of Jupiter (probably Ganymede) with the naked eye as early as 365 BCE, Galileo Galilei is credited with making the first recorded observation of Ganymede on January 7th, 1610 using his telescope. Together with Io, Europa and Callisto, he named them the “Medicean Stars” at the time – after his patron, the Grand Duke of Tuscany, Cosimo de’ Medici. Simon Marius, a German astronomer and contemporary of Galileo’s who claimed to have independently discovered Ganymede, suggested alternative names at the behest of Johannes Kepler. However, the names of Io, Europa, Ganymede and Callisto – which were all taken from classical mythology – would not come to formally be adopted until the 20th century. Illustration of Jupiter and the Galilean satellites. Credit: NASA Prior to this, the Galilean Moons were named Jupiter I through IV based on their proximity to the planet (with Ganymede designated as Jupiter III). Following the discovery of the moons of Saturn, a naming system based on that of Kepler and Marius was used for Jupiter’s moons. In Greek mythology, Ganymede was the son of King Tros (aka. Ilion), the namesake of the city of Troy (Ilium). Size, Mass and Orbit: With a mean radius of 2634.1 ± 0.3 kilometers (the equivalent of 0.413 Earths), Ganymede is the largest moon in the Solar System and is even larger than the planet Mercury. However, with a mass of 1.4819 x 10²³ kg (the equivalent of 0.025 Earths), it is only half as massive. This is due to Ganymede’s composition, which consists of water ice and silicate rock (see below). Ganymede’s orbit has a minor eccentricity of 0.0013, with an average distance (semi-major axis) of 1,070,400 km – varying from 1,069,200 km at periapsis to at 1,071,600 km apoapsis. Ganymede takes seven days and three hours to completes a single revolution. Like most known moons, Ganymede is tidally locked, with one side always facing toward the planet. Its orbit is inclined to the Jovian equator, with the eccentricity and inclination changing quasi-periodically due to solar and planetary gravitational perturbations on a timescale of centuries. These orbital variations cause the axial tilt to vary between 0 and 0.33°. Ganymede has a 4:1 orbital resonance with Io and a 2:1 resonance with Europa. Ganymede is the largest satellite in our solar system, larger than Mercury and Pluto, and three-quarters the size of Mars. Credit: NASA/JPL Essentially, this means that Io orbits Jupiter four times (and Europa twice) for every orbit made by Ganymede. The superior conjunction between Io and Europa occurs when Io is at periapsis and Europa is at apoapsis, and the superior conjunction between Europa and Ganymede occurs when Europa is at periapsis. Such a complicated resonance (a 4:2:1 resonance) is called the Laplace Resonance . Composition and Surface Features: With an average density of 1.936 g/cm3, Ganymede is most likely composed of equal parts rocky material and water ice. It is estimated that water ice constitutes 46–50% of the moon’s mass (slightly lower than that of Callisto) with the possibility of some additional volatile ices such as ammonia being

Where, theoretically, might one find objects squeezed to an infinite density?

Non-Singular Black Holes - One Universe at a Time One Universe at a Time In Black Holes by Brian Koberlein 13 May 2014 4 Comments The basic model of a black hole can be summed up as follows: gravity wins. The root cause of all black holes—be they tiny primordial black holes, solar mass black holes, or supermassive galactic black holes—is gravity. Squeeze enough mass into a small enough volume and gravity does the rest. The problem (at least according to general relativity) is that gravity does its job too well. Once matter enters a black hole, it simply cannot resist the pull of gravity. As a result all the matter within a black hole is squeezed down to a point of zero volume and infinite density, known as a singularity. Black hole singularities have long been the bugaboo of gravitational physics. They cause several problems, not the least of which is that the laws of physics as we understand them break down near the singularity. As a result there has been a lot of research on trying to eliminate singularities from our theoretical models. One way to get around singularities is by simply ignoring them. When black holes form, they become enclosed by an event horizon. A black hole’s event horizon is a kind of cosmic roach motel. Matter and energy can fall into a black hole, but anything that crosses the event horizon is forever stuck inside. Since the singularity always resides within the event horizon, we can never observe it from the outside. The singularity remains safely hidden from view. Roger Penrose even went so far as to propose the cosmic censorship hypothesis, which argues that every singularity must be enclosed by an event horizon, which hides it from the universe. But this hypothesis has never been proven in general, and several theoretical counter-examples (known as naked singularities) have been found. It would seem then that simply hiding singularities doesn’t solve the problem. Another approach to the problem is to find a mechanism by which the singularity never forms in the first place. Most of the effort in this area has been to find patchwork solutions to Einstein’s equations for general relativity. That is, patch together a black hole solution outside the event horizon (the exterior solution) with a non-singular solution inside the event horizon (the interior solution). By mathematically sewing the two solutions together, one gets a non-singular black hole. These solutions demonstrate that non-singular black holes are theoretically possible, but they say nothing about how such a black hole might form. Recently, however, Mbonye and Kazanas have found an exact solution to Einstein’s equations which contains no central singularity . Mbonye and Kazanas arrived at their solution by assuming a black hole contains exotic matter. Exotic matter is a theoretical material which has a negative energy density instead of the usual positive energy density. This negative energy density means that exotic matter can hold its own against gravity. When ordinary matter is squeezed by gravity, its energy density goes up. This higher energy density means gravity squeezes even more strongly, which means an even higher energy density, and so on. It is this feedback loop which means that gravity wins in the end. The harder gravity squeezes, the harder it can squeeze, until all that remains is the singularity. But exotic matter works differently. When gravity squeezes on exotic matter, its energy density goes down. This means gravity can’t win no matter how hard it tries, and it is impossible to form a singularity. What Mbonye and Kazanas have shown is that exotic matter allows for the creation of non-singular black holes. Mbonye and Kazanas don’t specify what this exotic matter is, but their formulation implies one possible candidate: dark energy. We don’t know what dark energy is, but we do know two things: it cannot be regular matter, and it has a negative energy density. Mbonye and Kazanas haven’t proven that their exotic matter is dark energy, but their work points to the idea that maybe, just maybe, one of newest mysteries o

Which is the largest moon of Saturn?

Titan, Largest Moon of Saturn, Explained (Infographic) Find out the facts about Titan's heavy atmosphere, lakes of hydrocarbons and the possibility of life. Credit: Karl Tate, SPACE.com contributor   Discovered in the year 1655, Titan is the largest of Saturn’s 62 charted moons. Titan is the only moon in the solar system with a dense atmosphere and stable bodies of liquid on its surface. The environment on Titan is deadly to human life, with a toxic atmosphere consisting mostly of nitrogen and methane. The surface temperature is minus 290 degrees F (minus 179 degrees C). Titan, 3,200 miles (5,150 kilometers) in diameter, is the second-largest moon in the solar system, one-and-a-half times the size of Earth’s moon . Titan is larger than the planet Mercury and is three-quarters the size of Mars. [ Amazing Photos of Titan ] In 2005, the Huygens lander revealed the surface of Titan is a wasteland of water ice and frozen hydrocarbons. Despite its lack of liquid water, some scientists believe Titan may support life, now or in the distant future when the sun’s heat increases. A rain of liquid ethane and methane falls to form lakes, making Titan the only planet or moon apart from Earth known to have liquid on its surface. In addition, some scientists think Titan may have large sub-surface oceans of liquid ammonia. Radar images of Titan’s north polar region show presumed lakes of liquid hydrocarbons.

Which is the largest planet in the solar system?

What is the Biggest Planet in the Solar System? - Universe Today   Universe Today What is the Biggest Planet in the Solar System? Article Updated: 23 Dec , 2015 by Matt Williams Ever since the invention of the telescope four hundred years ago, astronomers have been fascinated by the gas giant of Jupiter. Between it’s constant, swirling clouds, its many, many moons, and its Giant Red Spot, there are many things about this planet that are both delightful and fascinating. But perhaps the most impressive feature about Jupiter is its sheer size. In terms of mass, volume, and surface area, Jupiter is the biggest planet in our Solar System by a wide margin. But just what makes Jupiter so massive, and what else do we know about it? Size and Mass: Jupiter’s mass, volume, surface area and mean circumference are 1.8981 x 1027 kg, 1.43128 x 1015 km3, 6.1419 x 1010 km2, and 4.39264 x 105 km respectively. To put that in perspective, Jupiter diameter is roughly 11 times that of Earth, and 2.5 the mass of all the other planets in the Solar System combined. But, being a gas giant, Jupiter has a relatively low density – 1.326 g/cm3 – which is less than one quarter of Earth’s. This means that while Jupiter’s volume is equivalent to about 1,321 Earths, it is only 318 times as massive. The low density is one way scientists are able to determine that it is made mostly of gases, though the debate still rages on what exists at its core (see below). Composition: Jupiter is composed primarily of gaseous and liquid matter. It is the largest of the gas giants, and like them, is divided between a gaseous outer atmosphere and an interior that is made up of denser materials. It’s upper atmosphere is composed of about 88–92% hydrogen and 8–12% helium by percent volume of gas molecules, and approx. 75% hydrogen and 24% helium by mass, with the remaining one percent consisting of other elements. This cut-away illustrates a model of the interior of Jupiter, with a rocky core overlaid by a deep layer of liquid metallic hydrogen. Credit: Kelvinsong/Wikimedia Commons The atmosphere contains trace amounts of methane, water vapor, ammonia, and silicon-based compounds as well as trace amounts of benzene and other hydrocarbons. There are also traces of carbon, ethane, hydrogen sulfide, neon, oxygen, phosphine, and sulfur. Crystals of frozen ammonia have also been observed in the outermost layer of the atmosphere. The interior contains denser materials, such that the distribution is roughly 71% hydrogen, 24% helium and 5% other elements by mass. It is believed that Jupiter’s core is a dense mix of elements – a surrounding layer of liquid metallic hydrogen with some helium, and an outer layer predominantly of molecular hydrogen. The core has also been described as rocky, but this remains unknown as well. In 1997, the existence of the core was suggested by gravitational measurements, indicating a mass of from 12 to 45 times the Earth’s mass, or roughly 4%–14% of the total mass of Jupiter. The presence of a core is also supported by models of planetary formation that indicate how a rocky or icy core would have been necessary at some point in the planet’s history in order to collect its bulk of hydrogen and helium from the protosolar nebula. However, it is possible that this core has since shrunk due to convection currents of hot, liquid, metallic hydrogen mixing with the molten core. This core may even be absent now, but a detailed analysis is needed before this can be confirmed. The Juno mission , which launched in August 2011, is expected to provide some insight into these questions, and thereby make progress on the problem of the core. The temperature and pressure inside Jupiter increase steadily toward the core. At the “surface”, the pressure and temperature are believed to be 10 bars and 340 K (67 °C, 152 °F). At the “phase transition” region, where hydrogen becomes metallic, it is believed the temperature is 10,000 K (9,700 °C; 17,500 °F) and the pressure is 200 GPa. The temperature at the core boundary is estimated to be 36,000 K (35,700 °C; 64,300 °F) and th

What is the smallest planet in the solar system?

What is the Smallest Planet in the Solar System? - Universe Today   Universe Today What is the Smallest Planet in the Solar System? Article Updated: 24 Dec , 2015 by Fraser Cain The smallest planet in the Solar System is Mercury (the biggest planet is Jupiter). For the longest time, the smallest planet was considered to be Pluto, but now Pluto isn’t a planet any more, so we’re back to Mercury. Mercury measures 4879 km along its equator. Just for comparison, Earth is 12,742 km across. So Mercury is only 38% the diameter of Earth. In terms of volume, it’s even less. Mercury has only 0.05 the volume of the Earth. In other words, if the Earth was a hollow shell, you could fit 20 Mercurys inside with room to spare. Even though it’s very small, Mercury is extremely dense. It’s composed mostly of iron and rock, and so it has a density of 5.4 grams per cubic centimeter. Only Earth has a higher density, and that’s partly due to our larger size compressing down the interior. If Mercury were the same size as Earth, it would be much denser. If you could stand on the surface of Mercury, you would experience 38% of Earth’s gravity. Even thought Mars is a larger planet, you would experience more gravity on Mercury because it’s so dense. And here’s another take on the smallest planet in the Solar System , and here’s a link to NASA’s Solar System Exploration Guide . We have recorded a whole series of podcasts about the Solar System at Astronomy Cast . Check them out here.

Which is the brightest comet in the solar system?

Age of Comets Article, Orbit Information, Solar System Facts -- National Geographic No telescope was needed to see comet Hyakutake above the Palomar Observatory in San Diego County, California, as it came within 9.3 million miles (15 million kilometers) of Earth in 1996. Photograph by Don Bartletti Written by William Newcott Republished from the pages of National Geographic magazine Whistling and moaning, a 50-mile-an-hour (80-kilometer-an-hour) wind whipped among the telescope domes atop Kitt Peak. Just a few feet below, turning gray in the dusk, slid a river of clouds that had been rising and dropping all day. And high above, comet Hale-Bopp hung suspended like a feathery fishing lure, its tail curving off a bit, as if blown to the side by the punishing wind. One by one, stars winked on in a darkening sky. In each of the telescope domes, teams of astronomers prayed that the wind would drop below 40 miles per hour (64 kilometers an hour), the point at which they'd be able to open the sliding doors and get back to work. The sky turned indigo. Then black. Viewed from the summit, 6,873 feet (2,095 meters) above Arizona's Sonoran Desert, Hale-Bopp's bright dust tail, along with a dimmer, all but transparent blue one, seemed to grow by degrees. Among the brightest comets ever seen, Hale-Bopp had been visible for months from midtown Manhattan, of all places. But here, on a moonless night in the mountains in the desert, the length of Hale-Bopp's tail became visible—a wispy, delicate veil. Along with eclipses, comets have been the most feared and admired sky spectacles of all. But while astronomers have been able to predict eclipses for thousands of years, only in the 1700s was a comet's return correctly predicted, by Edmond Halley. Some comets swing around the sun every few years. Others, like Hale-Bopp, may take thousands of years. Most can be seen only with a telescope. But every once in a while—a few times a century, perhaps—an impressive one is visible to the naked eye. And in the past two years the world has witnessed not one but two of them. Hyakutake in 1996 had one of the longest tails on record, stretching more than halfway across the sky; Hale-Bopp in 1997 had one of the most brilliant heads, nearly as bright as the star Sirius. Add the Jupiter crash of comet Shoemaker-Levy in 1994, Halley's most recent visit in 1986, vivid comet West in 1976, and the scientifically signifiant—if visually disappointing—Kohoutek in 1973-74, and you could say that we are indeed living in the age of comets. Hovering in the most fragile of gravitational balances, a fleet of dirty, lumpy snowballs numbering in the trillions is barely held in orbit by the pull of the sun. They are stored in the Oort cloud, a huge, diffuse sphere of cometary nuclei in the far reaches of the solar system. Close to the sun, yet still beyond Neptune, circle what may well be their brethren, in a great disk called the Kuiper belt. Comets are leftovers, scraps of material that didn't make it to planethood in the events creating our solar system. Once, many astronomers believe, the solar system was full of comet nuclei, chunks of ice and dust left over from the formation of the sun. Most clumped together to form planets, leaving a relative handful—averaging perhaps a few miles wide, with temperatures as low as minus 400 degrees Fahrenheit (minus 240 degrees Celsius)—as time capsules of the early solar system. They orbit in a perpetual deep freeze until some subtle gravitational nudge upsets the delicate balance. Then the great fall begins. Imperceptibly at first, a snowball drifts toward the sun and steadily accelerates. As solar radiation heats the comet, the ice within sublimates, escaping as gas from vents at the surface. Sometimes jets of sublimating ice whirl off the rotating comet nucleus like a fireworks pinwheel. Dust trapped in the ice breaks free. Pushed back by the pressure of the sun's radiation, the dust streams out behind the comet in what appears as a fiery tail. Now the comet is among the fastest things in the solar system. It whizzes past the inne

What would you find if you travelled to the centre of the solar system?

If Jupiter and Saturn are gas giants, could you fly straight through them? Audio recording of Dr. Marc reading this page. Click play to hear me read this to you! Our friends at the W.A. Gayle Planetarium in Montgomery, Alabama, are curious to know, if Jupiter and Saturn are gas giants, could you fly straight through them? We think of a gas as something very . . . well, airy. After all, air is the gas we all know and love. We breathe it and fly planes right through it with no trouble. So it makes sense to think that a gas planet must be like a big, airy cloud floating out in space. But take another look at Jupiter and Saturn—or pictures of them. Notice how round they are. You will never see a cloud on Earth so nearly spherical. Why are Jupiter and Saturn so round if they are just gas? For that matter, why are any planets round? Well, the short answer is—gravity. Gravity causes all matter to be pulled toward all other matter. Let's think about this in more detail. When the planets were first forming, the solar system was a big, swirling disk of gas and dust, with the newborn Sun at the center. Bits of dust and clouds of gas were attracted to each other because of gravity. As these bits and clouds clumped, they attracted still more matter in their neighborhood and grew larger and larger until there was no longer any stray material nearby for them to attract. The growing planets were like big solar system vacuum cleaners, sweeping up all the debris in their paths. And they became round because gravity pulls equally toward the center of large masses such as planets, so anything sticking out gets pulled back to make a ball. The bigger a planet becomes, the heavier is the material weighing down on its center. Think of how it feels to dive under water. If you are wearing a face mask, you notice that as you dive deeper, the mask presses harder and harder on your face. Also, your ears start feeling the pressure even at 2 or 3 meters (5 or 10 feet) below the surface. The pressure you feel on your body is due to the weight of the water above you. The deeper you go, the heavier the water above you and so the greater the pressure on your body. Even on Earth's surface, each square inch of your body experiences 14.7 pounds of pressure due to the weight of the atmosphere above you. If you could dive down to the center of Earth, the pressure on your body would be about 3.5 million times as great! The center of Jupiter is more than 11 times deeper than Earth's center and the pressure may be 50 million to 100 million times that on Earth's surface! The tremendous pressure at the center of planets causes the temperatures there to be surprisingly high. At their cores, Jupiter and Saturn are much hotter than the surface of the Sun! Strange things happen to matter under these extraordinary temperatures and pressures. Hydrogen, along with helium, is the main ingredient of Jupiter's and Saturn's atmospheres. Deep in their atmospheres, the hydrogen turns into a liquid. Deeper still, the liquid hydrogen turns into a metal! But what's at the very center of these planets? The material becomes stranger and stranger the deeper you go. Scientists do not understand the properties of matter under the extreme environments inside Jupiter and Saturn. Many different forces and laws of nature are at work, and the conditions inside these planets are very difficult to create in a laboratory here on Earth. But you can be sure that you wouldn't be able to fly through these bizarre materials! As we now know, the gas giants are much more than just gas.

How many planets are there in the solar system?

How Many Planets are in the Solar System? - Universe Today   Universe Today How Many Planets are in the Solar System? Article Updated: 16 Oct , 2016 I’m just going to warn you, this is a controversial topic. Some people get pretty grumpy when you ask: how many planets are in the Solar System? Is it eight, ten, or more? I promise you this, though, we’re never going back to nine planets… ever. When many of us grew up, there were nine planets in the Solar System. It was like a fixed point in our brains. As kids, memorizing this list was an early right of passage of nerd pride: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. But then in 2005, Mike Brown discovered Eris, an icy object thought to be about the same size as Pluto, out beyond its orbit. That would bring the total number of planets to ten. Right? There’s no turning back, textbooks would need to be changed. In order to settle the dispute, the International Astronomical Union met in 2006, and argued for, and against Pluto’s planethood. Some astronomers advocated widening the number of planets to twelve, including Pluto, its moon Charon, the Asteroid Ceres, and the newly discovered Eris. In the end, they changed the definition of what makes a planet, and sadly, Pluto doesn’t make the cut: Here are the new requirements of planethood status: A planet has to orbit the Sun. Okay fine, Pluto does that. A planet needs enough gravity to pull itself into a sphere. Okay, spherical. Pluto’s fine there too. A planet needs to have cleared out its orbit of other objects. Uh oh, Pluto hasn’t done that. For example, planet Earth accounts for a million times the rest of the material in its orbit, while Pluto is just a fraction of the icy objects in its realm. The final decision was to demote Pluto from planet to dwarf planet. But don’t despair, Pluto is in good company. Ceres. Image credit: NASA There’s Ceres, the first asteroid ever discovered, and the smallest of the dwarf planets. The surface of Ceres is made of ice and rock, and it might even have a liquid ocean under its surface. NASA’s Dawn mission is flying there right now to give us close up pictures for the first time. Haumea, named after the Hawaiian goddess of fertility, is about a third the mass of Pluto, and has just enough gravity to pull itself into an ellipsoid, or egg shape. Even though it’s smaller, it’s got moons of its own. Makemake. Credit: NASA Makemake, a much larger Kuiper belt object, has a diameter about two-thirds the size of Pluto. It was discovered in 2005 by Mike Brown and his team. So far, Makemake doesn’t seem to have any moons. Eris is the most massive known dwarf planet, and the one that helped turn our definition of a planet upside-down. It’s 27% more massive than Pluto and the ninth most massive body that orbits the Sun. It even has a moon: Dysnomia. Pluto. Credit: ESO And of course, Pluto. The founding member of the dwarf family. Want an easy way to remember the eight planets, in order? Just remember this mnemonic: my very excellent mother just served us noodles. For all you currently writing angry tweets to Mike Brown , hold on a sec. Changing Pluto’s categorization is an important step that really needed to happen. The more we discover about our Universe, the more we realize just how strange and wonderful it is. When Pluto was discovered 80 years ago, we never could have expected the variety of objects in the Solar System. Categorizing Pluto as a dwarf planet helps us better describe our celestial home. So, our Solar System now has eight planets, and five dwarf planets. Podcast (audio): Download (Duration: 3:35 — 3.3MB) July 18, 2008 at 8:57 PM There are 12 planets in the solar system–Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, MakeMake, and Eris. It’s not the International Astronomical Union but four percent of that group that voted on excluding Pluto in a sloppy, nonsensical definition that states a dwarf planet is not a planet at all. The requirement that an object clear its orbit to be considered a planet is vague and if applied lit

Which planet is named after the Roman goddess of love?

Planet Venus Facts: A Hot, Hellish & Volcanic Planet Planet Venus Facts: A Hot, Hellish & Volcanic Planet By Charles Q. Choi, Space.com Contributor | November 4, 2014 09:01pm ET MORE Credit: NASA Venus, the second planet from the sun, is named for the Roman goddess of love and beauty. The planet — the only planet named after a female — may have been named for the most beautiful deity of her pantheon because it shone the brightest of the five planets known to ancient astronomers. In ancient times, Venus was often thought to be two different stars, the evening star and the morning star — that is, the ones that first appeared at sunset and sunrise. In Latin, they were respectively known as Vesper and Lucifer. In Christian times, Lucifer, or "light-bringer," became known as the name of Satan before his fall. Physical characteristics Venus and Earth are often called twins because they are similar in  size , mass, density,  composition  and gravity. However, the similarities end there. [ Photos: Venus, the Mysterious Planet Next Door ]  Venus is the hottest world in the solar system. Although Venus is not the planet closest to the sun, its dense atmosphere traps heat in a runaway version of the greenhouse effect that warms Earth. As a result,  temperatures on Venus  reach 870 degrees Fahrenheit (465 degrees Celsius), more than hot enough to melt lead. Probes that scientists have landed there have survived only a few hours  before being destroyed . Venus has a  hellish atmosphere  as well, consisting mainly of carbon dioxide with clouds of sulfuric acid, and scientists have only detected trace amounts of water in the atmosphere. The atmosphere is heavier than that of any other planet, leading to a surface pressure 90 times that of Earth. The surface of Venus is extremely dry. During its evolution, ultraviolet rays from the sun evaporated water quickly, keeping it in a  prolonged molten state . There is no liquid water on its surface today because the scorching heat created by its ozone-filled atmosphere would cause any to boil away. Roughly two-thirds of the Venusian surface is covered by flat, smooth plains that are marred by thousands of volcanoes, some which are  still active today , ranging from about 0.5 to 150 miles (0.8 to 240 kilometers) wide, with lava flows carving long, winding canals up to more than 3,000 miles (5,000 km) in length, longer than on any other planet. Six mountainous regions make up about one-third of the Venusian surface. One mountain range, called Maxwell, is about 540 miles (870 km) long and reaches up to some 7 miles (11.3 km) high, making it the highest feature on the planet. Venus also possesses a number of surface features unlike anything on Earth. For example, Venus has coronae, or crowns — ringlike structures that range from roughly 95 to 360 miles (155 to 580 km) wide. Scientists believe these formed when hot material beneath the crust rises up, warping the planet’s surface. Venus also has tesserae, or tiles — raised areas in which many ridges and valleys have formed in different directions. With conditions on Venus that could be described as infernal, the ancient name for Venus — Lucifer — seems to fit. However, this name did not carry any fiendish connotations; Lucifer means "light-bringer," and when seen from Earth, Venus is brighter than any other planet or even any star in the night sky because of its highly reflective clouds and its closeness to our planet. Venus takes 243 Earth days to rotate on its axis, by far the slowest of any of the major planets, and because of this sluggish spin, its metal core cannot generate a magnetic field similar to Earth's. Orbital characteristics If viewed from above, Venus rotates on its axis the opposite way that most planets rotate. That means on Venus, the sun would appear to rise in the west and set in the east. On Earth, the sun appears to rise in the east and set in the west. The Venusian year — the time it takes to orbit the sun — is about 225 Earth days long. Normally, that would mean that days on Venus would be longer than years. However, becau

What kind of extraterrestrial objet has been named after the 17th-century astronomer Edmond Halley?

Astronomy - 2 | Britannica.com Astronomy science that encompasses the study of all extraterrestrial objects and phenomena. Browse Subcategories: (243) Displaying 1 - 100 of 800 results 51 Pegasi fifth-magnitude star located 48 light-years away from Earth in the constellation Pegasus, the first sunlike star confirmed to possess a planet. 51 Pegasi, which has physical properties (luminosity and temperature, for example) very similar to those of... 61 Cygni first star whose distance from Earth was measured. German astronomer Friedrich Wilhelm Bessel obtained a value of 10.3 light-years in 1838; the European Space Agency satellite Hipparcos made much more accurate distance measurements than ground-based... Abūʾl-Wafāʾ a distinguished Muslim astronomer and mathematician, who made important contributions to the development of trigonometry. Abūʾl-Wafāʾ worked in a private observatory in Baghdad, where he made observations to determine, among other astronomical parameters,... accretion disk a disklike flow of gas, plasma, dust, or particles around any astronomical object in which the material orbiting in the gravitational field of the object loses energy and angular momentum as it slowly spirals inward. In astrophysics, the term accretion... Achernar brightest star in the constellation Eridanus and the ninth brightest star in the sky. Achernar (Arabic for “end of the river”) is 144 light-years from Earth. It is a binary star with a B-type star, Achernar A, as its primary and a much fainter A-type... Adams, John Couch British mathematician and astronomer, one of two people who independently discovered the planet Neptune. On July 3, 1841, Adams had entered in his journal: “Formed a design in the beginning of this week of investigating, as soon as possible after taking... Adams, Walter American astronomer who is best known for his spectroscopic studies. Using the spectroscope, he investigated sunspots and the rotation of the Sun, the velocities and distances of thousands of stars, and planetary atmospheres. Born of missionary parents... Airy, Sir George Biddell English scientist who was astronomer royal from 1835 to 1881. Airy graduated from Trinity College, Cambridge, in 1823. He became Lucasian professor of mathematics at Cambridge in 1826 and Plumian professor of astronomy and director of the Cambridge observatory... Aitken, Robert Grant American astronomer who specialized in the study of double stars, of which he discovered more than 3,000. From 1891 to 1895 Aitken was professor of mathematics and astronomy at the University of the Pacific, Stockton, Calif. In 1895 he joined the staff... Akiyama Toyohiro Japanese journalist and television reporter, the first Japanese citizen and the first journalist to travel into space. Akiyama was also the first fare-paying civilian passenger (nonprofessional astronaut) to participate in a spaceflight. Akiyama earned... Al Saud, Sultan ibn Salman the first Saudi Arabian citizen, the first Arab, the first Muslim, and the first member of a royal family to travel into space. Educated in the United States, Sultan received a degree in mass communications from the University of Denver (Colorado) and... al-Ḥanafī, ʿAlam al-Dīn Egyptian mathematician, astronomer, and engineer. He wrote a treatise on Euclid’s postulates, built water mills and fortifications on the Orontes River, and constructed the second-oldest existing Arabic celestial globe. Alcock, George Eric Deacon British schoolteacher and amateur astronomer who was ranked as one of the world’s finest amateur astronomers; his 10 major discoveries exceeded the previous record of 8 discoveries made by 18th-century English astronomer Caroline Herschel. Despite the... Alcor from Arabic “Faint One” star with apparent magnitude of 4.01. Alcor makes a visual double with the brighter star Mizar in the middle of the handle of the Big Dipper (Ursa Major). The two are 1.2 light-years apart and may be gravitationally bound to each... Aldebaran Arabic “The Follower” reddish giant star in the constellation Taurus. Aldebaran is one of the 15 brightest stars,

What was the first artificial satellite?

Sputnik NASA Main Page Multimedia Interactive Feature on 50th Anniversary of the Space Age Sputnik and The Dawn of the Space Age History changed on October 4, 1957, when the Soviet Union successfully launched Sputnik I. The world's first artificial satellite was about the size of a beach ball (58 cm.or 22.8 inches in diameter), weighed only 83.6 kg. or 183.9 pounds, and took about 98 minutes to orbit the Earth on its elliptical path. That launch ushered in new political, military, technological, and scientific developments. While the Sputnik launch was a single event, it marked the start of the space age and the U.S.-U.S.S.R space race.  The story begins in 1952, when the International Council of Scientific Unions decided to establish July 1, 1957, to December 31, 1958, as the International Geophysical Year (IGY) because the scientists knew that the cycles of solar activity would be at a high point then. In October 1954, the council adopted a resolution calling for artificial satellites to be launched during the IGY to map the Earth's surface.  In July 1955, the White House announced plans to launch an Earth-orbiting satellite for the IGY and solicited proposals from various Government research agencies to undertake development. In September 1955, the Naval Research Laboratory's Vanguard proposal was chosen to represent the U.S. during the IGY.  The Sputnik launch changed everything. As a technical achievement, Sputnik caught the world's attention and the American public off-guard. Its size was more impressive than Vanguard's intended 3.5-pound payload. In addition, the public feared that the Soviets' ability to launch satellites also translated into the capability to launch ballistic missiles that could carry nuclear weapons from Europe to the U.S. Then the Soviets struck again; on November 3, Sputnik II was launched, carrying a much heavier payload, including a dog named Laika.  Immediately after the Sputnik I launch in October, the U.S. Defense Department responded to the political furor by approving funding for another U.S. satellite project. As a simultaneous alternative to Vanguard, Wernher von Braun and his Army Redstone Arsenal team began work on the Explorer project.  On January 31, 1958, the tide changed, when the United States successfully launched Explorer I. This satellite carried a small scientific payload that eventually discovered the magnetic radiation belts around the Earth, named after principal investigator James Van Allen. The Explorer program continued as a successful ongoing series of lightweight, scientifically useful spacecraft.  The Sputnik launch also led directly to the creation of National Aeronautics and Space Administration (NASA). In July 1958, Congress passed the National Aeronautics and Space Act (commonly called the "Space Act") , which created NASA as of October 1, 1958 from the National Advisory Committee for Aeronautics (NACA) and other government agencies.  Updated October 10, 2007

What is the name of the space shuttle destroyed in midair 28 Jan 1986?

Challenger Disaster Live on CNN - YouTube Challenger Disaster Live on CNN Want to watch this again later? Sign in to add this video to a playlist. Need to report the video? Sign in to report inappropriate content. Rating is available when the video has been rented. This feature is not available right now. Please try again later. Uploaded on Jul 24, 2007 January 28th, 1986 at 11:39am EDT - The Space Shuttle Challenger Explodes on its 10th flight during mission STS-51-L. The explosion occurred 73 seconds after liftoff and was actually the result of rapid deceleration and not combustion of fuel. CNN was the only national news station to broadcast the mission live, so thus what you are witnessing on this video is the only coverage of the disaster as it happened when it did. Approximately 17% of Americans witnessed the launch live, while 85% of Americans heard of the news within 1 hour of the event. According to a study, only 2 other times in history up to that point had news of an event disseminated so fast - the first being the announcement of JFK's assassination in 1963, the second being news spread among students at Kent State regarding the news of FDR's death in 1945. It has been estimated at the time that nearly 48% of 9-13 year olds witnessed the event in their classrooms, as McAuliffe was in the spotlight. The 25th Space Shuttle mission altered the history of manned space exploration and represented the first loss of an American crew during a space mission (Apollo 1 was during a training exercise). Christa McAuliffe was slated to be the first teacher in space for the Teacher in Space Program. As her maximum altitude was ~65,000ft (12.31 miles), she never made it to space. That title was given to Barbara Morgan of STS-118 aboard the shuttle Endeavour in August 2007, 22 and a half years after the Challenger Disaster. Morgan served as McAuliffe's backup during STS-51-L. As Morgan is now part of the Educator in Space Program, she will be credited as the first "educator" in space, to distinguish her from McAuliffe. Aboard Challenger during STS-51-L: Sharon Christa McAuliffe (Payload Specialist - Teacher in Space) Category

What, ultimately, will the sun become?

The Sun Will Eventually Engulf Earth--Maybe - Scientific American Space The Sun Will Eventually Engulf Earth--Maybe Researchers debate whether Earth will be swallowed by the sun as it expands into a red giant billions of years from now By David Appell on September 1, 2008 Credit: Lynette Cook Photo Researchers, Inc. Advertisement | Report Ad The future looks bright—maybe too bright. The sun is slowly expanding and brightening, and over the next few billion years it will eventually desiccate Earth, leaving it hot, brown and uninhabitable. About 7.6 billion years from now, the sun will reach its maximum size as a red giant: its surface will extend beyond Earth’s orbit today by 20 percent and will shine 3,000 times brighter. In its final stage, the sun will collapse into a white dwarf. Although scientists agree on the sun’s future, they disagree about what will happen to Earth. Since 1924, when British mathematician James Jeans first considered Earth’s fate during the sun’s red giant phase, a bevy of scientists have reached oscillating conclusions. In some scenarios, our planet escapes vaporization; in the latest analyses, however, it does not. The answer is not straightforward, because although the sun will expand beyond Earth’s orbit, or one astronomical unit (AU), it will lose mass along the way. As a result, Earth should drift outward as the gravitational tug lessens over time. (At its maximum radius of 1.2 AU, the sun will have lost about one third of its mass, compared with its current heft.) In this way, Earth could escape solar envelopment. But other factors complicate the analysis. Drag on the planet from the sun’s outermost, tenuous layers will cause Earth to drift inward. Smaller forces from the other planets—all in turn reacting to the same reducing, expanding sun—are even more difficult to account for completely. Earlier this year two teams reported different kinds of calculations indicating that Earth will be swallowed up by the sun. In a calculation that would thrill any college junior studying classical mechanics, Lorenzo Iorio of Italy’s National Institute of Nuclear Physics used perturbation theory. It simplifies analyses by dropping relatively small factors, thereby making complex equations of motions that describe the interactions between the sun and Earth mathematically manageable. Assuming that the sun’s yearly mass loss (currently about one part in 100 trillion) remains small for the duration of its evolution to the red giant phase, Iorio calculates that Earth will move outward at about three millimeters a year, or only 0.0002 AU by the sun’s red giant phase. But at that point the sun will balloon up, in only a million years, to 1.2 AU in radius, thus vaporizing Earth. Iorio’s paper, submitted to Astrophysics and Space Science, has not yet been peer-reviewed. Several scientists question whether quantities that Iorio assumes are small will indeed remain small throughout the sun’s evolution. Even if Iorio got his number crunching wrong, he may have the right answer. In an analysis published in the May Monthly Notices of the Royal Astronomical Society, Klaus-Peter Schröder of the University of Guanajuato in Mexico and Robert Smith of the University of Sussex in England also conclude that Earth is doomed, by using more exact solar models and by considering tidal interactions. As the sun loses mass and expands, its rotation rate must also slow down—physics students learn this relation as the conservation of angular momentum. The slowed rotation causes a tidal bulge on the sun’s surface. The gravity exerted by this bulge pulls Earth inward. With such a consideration, the researchers find that any planet with a present-day orbital radius of less than 1.15 AU will ultimately perish. Could Earth be saved if someone is still left at home? In a bold piece of astronomical engineering, Don Korycansky of the University of California, Santa Cruz, and his colleagues have proposed nudging Earth with a large asteroid arranged to pass nearby periodically. It could take one billion years to move our planet out to somewhe

Which planet takes almost 30 Earth years to orbit the sun?

How Long Is A Year On The Other Planets? - Universe Today   Universe Today How Long Is A Year On The Other Planets? Article Updated: 29 Jan , 2016 by Matt Williams Here on Earth, we to end to not give our measurements of time much thought. Unless we’re griping about Time Zones, enjoying the extra day of a Leap Year, or contemplating the rationality of Daylight Savings Time, we tend to take it all for granted. But when you consider the fact that increments like a year are entirely relative, dependent on a specific space and place, you begin to see how time really works. Here on Earth, we consider a year to be 365 days. Unless of course it’s a Leap Year, which takes place every four years (in which it is 366). But the actual definition of a year is the time it takes our planet to complete a single orbit around the Sun. So if you were to put yourself in another frame of reference – say, another planet – a year would work out to something else. Let’s see just how long a year is on the other planets, shall we? A Year On Mercury: To put it simply, Mercury has an orbital period of 88 days (87.969 to be exact), which means a single year is 88 Earth days – or the equivalent of about 0.241 Earth years. But here’s the thing. Because of Mercury’s slow rotation (once every 58.646 days) and its rapid orbital speed (47.362 km/s), one day on Mercury actually works out to 175.96 Earth days. MESSENGER maps of Mercury – a monochrome map at 250 m/pixel and an eight-color (left), 1-km/pixel color map. Small gaps will be filled in during the next solar day (right). Credit: NASA/Johns Hopkins University APL/Carnegie Institution of Washington So basically, a single year on Mercury is half as long as a Mercurian (aka. Hermian) day. This is due to Mercury being the closest planet to the Sun, ranging from 46,001,200 km at perihelion to 69,816,900 km at aphelion. At that distance, the planet shoots around the Sun faster than any other in our Solar System and has the shortest year. In the course of a year, Mercury experiences intense variations in surface temperature – ranging from 80 °K (-193.15 °C;-315.67 °F) to 700 °K (426.85 °C; 800.33 °F). However, this is due to the planet’s varying distance from the Sun and its spin, which subjects one side to extended periods of extremely hot temperatures and one side to extended periods of night. Mercury’s low axial tilt (0.034°) and its rapid orbital period means that there really is no seasonal variation on Mercury. Basically, one part of the year is as hellishly hot, or horribly cold, as any other. A Year On Venus: The second closest planet to our Sun, Venus completes a single orbit once ever 224.7 days. This means that a single year on Venus works out to about 0.6152 Earth years. But, once again, things are complicated by the fact that Venus has an unusual rotation period. In fact, Venus takes 243 Earth days to rotate once on its axis – the slowest rotation of any planet – and its rotation is retrograde to its orbital path. The planet Venus, as imagined by the Magellan 10 mission. Credit: NASA/JPL Combined with its orbital period, this means that a single solar day on Venus (the time between one sunup to the next) is 117 Earth days. So basically, a single year on Venus is lasts 1.92 Venusian (aka. Cytherean) days. Again, this would make for some confusing time-cycles for any humans trying to make a go of it on Venus! Also, Venus has a very small axial tilt – 3° compared to Earth’s 23.5° – and its proximity to the Sun makes for a much shorter seasonal cycle – 55-58 days compared to Earth’s 90-93 days. Add to that its unusual day-night cycle, variations are very slight. In fact, the temperate on Venus is almost always a brutal 736 K (463 °C ; 865 degrees °F), which is hot enough to melt lead! A Year On Earth: Comparatively speaking, a year on Earth is pretty predictable, which is probably one of the reasons why life is able to thrive here. In short, our planet takes 365.2564 solar days to complete a single orbit of the Sun, which is why we add an extra day to the calendar every four years (i.e. a Leap Yea

What is the most distant object visible to the naked eye?

Farthest Naked Eye Object Farthest Naked Eye Object Loose Ends Maintained by suitti@uitti.net , Stephen Uitti One mostly hears that the Andromeda Galaxy (M31), at 2.25 million (2,250,000) light years is the most distant naked eye object. I've seen it, and it is the farthest naked eye object I've seen. Oh, alright, I was wearing contacts. But without them, or glasses, the most distant object I can see is the Sun. For that, I have to wait until morning. M31 is the largest galaxy in the local group. The Triangulum Spiral (M33) is the third largest member of the Local Group, and some people claim to have seen it with the naked eye. It is a face on spiral galaxy. M33 is more like 2.78 million (2,780,000) light years. Bode's Galaxy (M81), at 12 million (12,000,000) light years has been spotted by several people. This page at SEDS on M81 has a description of how to see it. The trouble is, at Magnitude 6.9, M81 is dimmer than most consider naked eye. It depends on whose eye it is, and also where the feet are standing. It has to be an exceptionally dark sky site, probably at some altitude, at the right time of year, etc. Still, it's my answer to the question. I'm done. Finished. Except for the following speculation. Apparently, SN1987A was a naked eye event. This was the big super nova in the Large Magellanic Cloud (LMC), visible from the southern hemisphere in early 1987. It wasn't a distance record holder, as the LMC is considered a satellite galaxy of the Milky Way. The LMC is only about 100,000 light years out. This is about the distance to the outer edge of the far side of the Milky Way. So one could consider the LMC to be part of the Milky Way. The LMC is already in the process of being torn apart, eaten really, by the Milky Way. The Milky Way is the second largest galaxy in the Local Group. Since super novas can outshine their host galaxies, it seems possible that one could push the farthest object out a bit, if only for a few days. Say there is a galaxy, oh, about 15 million (15,000,000) light years away. It isn't a naked eye object now. But what if it hosts a bright super nova? That object would be the same distance, and could be naked eye visible for a few days. There are other bright things too. I'm not aware of any naked eye visible quasars, for example. There is at least one quasar, 3C 273, visible in a 6 inch (150 mm) telescope. It's magnitude is 12.9. It sits about 2 billion (2,000,000,000) light years away. While no one would call this naked eye observing, it does come under the concept of eyeball astronomy - which is distinguished from astrophotography. How far could one see with eyeball astronomy? That, of course, depends on the telescope. It mostly depends on the light collecting area of the big end of the telescope. There is a story that several people have looked through one of the 10 meter (32.8 foot) Keck telescopes. Each of the twin Keck scopes were, at the time, the largest instruments on Earth. This pushes the concept of eyeball astronomy to interesting limits. Extrapolating from smaller scopes at good dark sky sites, one should be able to see objects as faint as 23rd magnitude with a Keck. Quasars that would appear around that magnitude might be far enough away to be red shifted out of the visible spectrum. But, perhaps higher frequency photons, maybe X-rays, will have been red shifted into the visible spectrum. It seems reasonable to assume that one would be able to peer most of the way back to the beginning of the Universe, or most of the way across the visible part of the Universe. At these distances, due to the expansion of the Universe, light years are not even approximately years back in time. The Universe is about 13.7 billion (13,700,000,000) years old. However, the distance to the most distant detectable objects is about 46 billion (46,000,000,000) light-years.

Which planet is the densest?

How Dense Are The Planets? - Universe Today   Universe Today How Dense Are The Planets? Article Updated: 18 Feb , 2016 by Matt Williams The eight planets of our Solar System vary widely, not only in terms of size, but also in terms of mass and density (i.e. its mass per unit of volume). For instance, the 4 inner planets – those that are closest to the Sun – are all terrestrial planets , meaning they are composed primarily of silicate rocks or metals and have a solid surface. On these planets, density varies the farther one ventures from the surface towards the core, but not considerably. By contrast, the 4 outer planets are designated as gas giants (and/or ice giants) which are composed primarily of of hydrogen, helium, and water existing in various physical states. While these planets are greater in size and mass, their overall density is much lower. In addition, their density varies considerably between the outer and inner layers, ranging from a liquid state to materials so dense that they become rock-solid. Density also plays a vital role in determining a planet’s surface gravity and is intrinsic to understanding how a planet formed. After the formation of the Sun at the center of our Solar System, the planets were formed from a protoplanetary disc . Whereas the terrestrial planets resulted from dust grains in the inner Solar System, planets in the outer Solar System accreted enough matter for their gravity to hold on to the nebula’s leftover gas. The Solar System. Image Credit: NASA The more gas they held onto, the larger they became. And the larger they became, the more matter they would accumulate, until such tie that they reached a critical point. Whereas the gas giants of Jupiter and Saturn grew exponentially, the ice giants (Uranus and Neptune), with only a few Earth masses of nebular gas, never reached that critical point. In all cases, density is measured as the number of grams per cubic cm (or g/cm³). Density of Mercury: Ad a terrestrial planet, Mercury is composed of metals and silicate material. Mercury’s mean density is the second-highest in the Solar System, which is estimated to be 5.427 g/cm3 – only slightly less than Earth’s density of 5.515 g/cm3.However, if the effects of gravitational compression – in which the effects of gravity reduce the size of an object and increases its density – then Mercury is in fact more dense than Earth, with an uncompressed density of 5.3 g/cm³ compared to Earth’s 4.4 g/cm³. These estimates can be also used to infer details of its inner structure. Compared to Earth, Mercury is much smaller, which is why it inner regions are subject to less in the way of compression. Therefore, its high density is believed to be the result of a large, and iron-rich core. All told, metals like iron and nickel are believed to make up 70% of the planet’s mass (higher than any other planet), while silicate rock accounts for just 30%. Internal structure of Mercury: 1. Crust: 100–300 km thick 2. Mantle: 600 km thick 3. Core: 1,800 km radius. Credit: MASA/JPL Several theories for this have been suggested, but the predominant one claims that Mercury had a thicker silicate crust earlier in its history. This crust was then largely blown off when a large planetesimal collided with the planet. Combined with its size and mass, Mercury has a surface gravity of 3.7 m/s2, which is the equivalent of 0.38 of Earth’s gravity (aka. 1 g). Density of Venus: The second planet from our Sun, as well as the second-closest terrestrial planet, Venus has a mean density of 5.243 g/cm3. Again, this is very close to Earth’s own density. And while much remains unknown about Venus’ geology and seismology, astronomers have an idea of Venus’ composition and structure based on comparative estimates of its size, mass and its density. In short, it is believed that Venus’ makeup and internal structure are very similar to Earth’s, consisting of a core, a mantle, and a crust. Also like Earth, the interior is though to be composed of iron-rich minerals, while silicate minerals make up the mantle and crust. The slightly smaller siz

What is the name given to the super dense stars that sometimes result form a supernova?

What is a Supernova – Definition & Facts of Star Explosion in Space – PlanetFacts.org Supernova What is a Supernova? To say in three words, a supernova is an exploding star. Okay, that was more than three, but you get the point. A supernova is more significant than a nova, but less so than a hypernova. Supernovae are very bright and generate bursts of radiation that can briefly outshine a whole galaxy before declining in brightness over many weeks or months. In this period a supernova can emit as much energy as the Sun might over its entire lifetime. How Supernovae are Studied By using optical telescopes, astronomers can approximate the amount of light generated by a supernova. These measurements can be used to determine how the luminosity and color of a supernova vary with time. Astronomers may examine the light through a prism, which breaks the light from a supernova into the spectrum of colors that composes it. From this, astronomers can gauge how the brightness of light depends on that light’s wavelength. The luminosity could change at all wavelengths. The spectrum of a supernova can very with time as well, until it fades entirely of course. The study of a supernova is more than just a study of any ordinary light show. Both the light and spectrum of color of a supernova can be used to make conclusions about the physics that occurs during and after supernova explosions. Understanding how a supernova explosion occurs and progresses is crucial to understanding why certain stars go boom. Supernovae are responsible for producing and dispersing elements into the interstellar medium. The elements that form stars, planets, and life on Earth are created and spread by supernovae. You could say that we are made of stardust. Naming Convention Supernovae are reported to the International Astronomical Union’s Central Bureau for Astronomical Telegrams, which assign them a name. The name begins with “SN”, the prefix for supernova, followed by the year, followed by a string of letter from A to Z. The first 26 supernovae are attached with a capital letter (A-Z). Following this are pairs of lower-case letters, such as aa, ab, ac, so on and so forth. For example the 367th supernova discovered in 2005 would be named SN 2005 nc. This naming convention was utilized since 1885. However, up until 1947, rarely would more than one supernova was found per year. Two-letter designations were scarcely necessary until 1987, and since 1988, they have been necessary more and more every year. Supernovae Types Since 1941, Rudolf Minkowski discovered that some spectra contain hydrogen and some do not, and therefore supernovae are classified by Type I, ones lacking hydrogen in their spectra, and Type II, ones that strongly show strong hydrogen lines. Since 1985, Type I supernovae have been classified further. Type Ia supernovae have a silicon spectral line at 615 nm, and Type Ib does not. Type Ib supernovae have strong helium lines, and Type Ic do not. Type I supernovae are classified such because of the sharp maxima and smooth decay of light in their light curves. The initiation of a Type I supernova can be modeled as an explosion of a carbon white dwarf that is crushed under the pressure of electron degeneracy. Supernovae Models The assumption follows that a white dwarf accumulates enough mass that it exceeds the Chandrasekhar limit of 1.4 solar masses (for white dwarves, this is the mass at which the star’s core can no longer resist gravitational collapse). The core temperature of the white dwarf rises dramatically, setting off chains of nuclear fusion reactions that essentially blow the star up. This model is consistent with the fact that Type I supernovae are hydrogen deficient, since white dwarves contain nearly zero hydrogen. Furthermore, the slow decay of light is consistent with the model, because the radioactive decay of unstable heavy elements produced by the supernova produces most of the energy. Supernovae of Type I can be further categorized into Types Ia, Ib, and Ic. Type Ia supernovae are indicated by the lack of

What shape is the Milky Way?

What shape is the Milky Way? - How the Milky Way Works | HowStuffWorks What shape is the Milky Way? Image courtesy NASA Edwin Hubble studied galaxies and classified them into various types of elliptical and spiral galaxies. The spiral galaxies were characterized by disk shapes with spiral arms. It stood to reason that because the Milky Way was disk-shaped and because spiral galaxies were disk-shaped, the Milky Way was probably a spiral galaxy. In the 1930s, astronomer R. J. Trumpler realized that the estimates of the size of the Milky Way galaxy by Kapetyn and others were off because the measurements had relied on observations in the visible wavelengths. Trumpler concluded that the vast amounts of dust in the plane of the Milky Way absorbed light in the visible wavelengths and caused faraway stars and clusters to appear dimmer than they actually were. Therefore, to accurately map stars and star clusters within the disk of the Milky Way, astronomers would need a way to peer through the dust. Up Next Could a planet exist without a host star? In the 1950s, the first radio telescopes were invented. Astronomers discovered that hydrogen atoms emitted radiation in the radio wavelengths and that these radio waves could penetrate the dust in the Milky Way. So, it became possible to map the spiral arms of the Milky Way. The key was marker stars like those used in distance measurements. Astronomers found that class O and B stars would work. These stars had several features: Brightness: They're highly visible and are often found in small groups or associations. Heat: They emit multiple wavelengths (visible, infrared, radio). Short life: They live for about 100 million years, so, considering the rate at which stars orbit the galaxy's center, they don't move far from where they were born. Astronomers could use radio telescopes to accurately map the positions of these O and B stars and use the Doppler shifts of the radio spectrum to determine their rates of motion. When they did this with many stars, they were able to produce combined radio and optical maps of the Milky Way's spiral arms. Each arm is named for the constellations that exist within it. Astronomers think that the motion of the material around the galactic center sets up density waves (areas of high and low density), much like you see when you stir cake batter with an electric mixer. These density waves are thought to cause the spiral nature of the galaxy. So, by examining the sky in multiple wavelengths (radio, infrared, visible, ultraviolet, X-ray ) with various ground-based and space-based telescopes, we can get different views of the Milky Way. On the next page we'll look into exactly what's inside the Milky Way. The Doppler Effect Much like the high-pitched sound from a fire-truck siren gets lower as the truck moves away, the movement of stars affects the wavelengths of light that we receive from them. This phenomenon is called the Doppler effect. We can measure the Doppler effect by measuring lines in a star's spectrum and comparing them to the spectrum of a standard lamp. The amount of the Doppler shift tells us how fast the star is moving relative to us. In addition, the direction of the Doppler shift can tell us the direction of the star's movement. If the spectrum of a star is shifted to the blue end, the star is moving toward us; if the spectrum is shifted to the red end, the star is moving away from us.

When was the first Pioneer space probe launched?

NASA - NSSDCA - Spacecraft - Details NSSDCA/COSPAR ID: 1958-007A Description Pioneer 1, the second and most successful of three project Able space probes and the first spacecraft launched by the newly formed NASA, was intended to study the ionizing radiation, cosmic rays, magnetic fields, and micrometeorites in the vicinity of the Earth and in lunar orbit. Due to a launch vehicle malfunction, the spacecraft attained only a ballistic trajectory and never reached the Moon. It did return data on the near-Earth space environment. Spacecraft and Subsystems Pioneer 1 consisted of a thin cylindrical midsection with a squat truncated cone frustrum on each side. The cylinder was 74 cm in diameter and the height from the top of one cone to the top of the opposite cone was 76 cm. Along the axis of the spacecraft and protruding from the end of the lower cone was an 11 kg solid propellant injection rocket and rocket case, which formed the main structural member of the spacecraft. Eight small low-thrust solid propellant velocity adjustment rockets were mounted on the end of the upper cone in a ring assembly which could be jettisoned after use. A magnetic dipole antenna also protruded from the top of the upper cone. The shell was composed of laminated plastic. The total mass of the spacecraft after vernier separation was 34.2 kg, after injection rocket firing it would have been 23.2 kg. The scientific instrument package had a mass of 17.8 kg and consisted of an image scanning infrared television system to study the Moon's surface to a resolution of 1 milliradian, an ionization chamber to measure radiation in space, a diaphragm/microphone assembly to detect micrometeorites, a spin-coil magnetometer to measure magnetic fields to 5 microgauss, and temperature-variable resistors to record spacecraft internal conditions. The spacecraft was powered by nickel-cadmium batteries for ignition of the rockets, silver cell batteries for the television system, and mercury batteries for the remaining circuits. Radio transmission was at on 108.06 MHz through an electric dipole antenna for telemetry and doppler information at 300 mW and a magnetic dipole antenna for the television system at 50 W. Ground commands were received through the electric dipole antenna at 115 MHz. The spacecraft was spin stabilized at 1.8 rps, the spin direction was approximately perpendicular to the geomagnetic meridian planes of the trajectory. Mission Profile The spacecraft did not reach the Moon as planned due to an incorrectly set valve in the upper stage which caused an accelerometer to give faulty information leading to a slight error in burnout velocity (the Thor second stage shut down 10 seconds early) and angle (3.5 degrees). This resulted in a ballistic trajectory with a peak altitude of 113,800 km around 1300 local time. The real-time transmission was obtained for about 75% of the flight, but the percentage of data recorded for each experiment was variable. Except for the first hour of flight, the signal to noise ratio was good. The spacecraft ended transmission when it reentered the Earth's atmosphere after 43 hours of flight on October 13, 1958 at 03:46 UT over the South Pacific Ocean. A small quantity of useful scientific information was returned, showing the radiation surrounding Earth was in the form of bands and measuring the extent of the bands, mapping the total ionizing flux, making the first observations of hydromagnetic oscillations of the magnetic field, and taking the first measurements of the density of micrometeorites and the interplanetary magnetic field. Alternate Names Launch Site: Cape Canaveral, United States Mass: 34.2 kg Department of Defense-Department of the Air Force (United States) NASA-Office of Space Science Applications (United States) Disciplines

Which planet id named after the sky-god who was father of the Titans?

Planetary Names: Planet and Satellite Names and Discoverers International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN) Planetary Names: Planet and Satellite Names and Discoverers Home Named Mercurius by the Romans because it appears to move so swiftly.   Discoverer Venus Roman name for the goddess of love. This planet was considered to be the brightest and most beautiful planet or star in the heavens. Other civilizations have named it for their god or goddess of love/war.   Discoverer Earth The name Earth comes from the Indo-European base 'er,'which produced the Germanic noun 'ertho,' and ultimately German 'erde,' Dutch 'aarde,' Scandinavian 'jord,' and English 'earth.' Related forms include Greek 'eraze,' meaning 'on the ground,' and Welsh 'erw,' meaning 'a piece of land.'     Earth I (Moon) Every civilization has had a name for the satellite of Earth that is known, in English, as the Moon. The Moon is known as Luna in Italian, Latin, and Spanish, as Lune in French, as Mond in German, and as Selene in Greek.     Martian System The names of the moons of Mars and the English translations of the names were specifically proposed by their discoverer, Asaph Hall, and as such, they have been accepted and retained under the current IAU nomenclature. Body Discoverer Mars Named by the Romans for their god of war because of its red, bloodlike color. Other civilizations also named this planet from this attribute; for example, the Egyptians named it "Her Desher," meaning "the red one."     Mars I (Phobos) Inner satellite of Mars. Named for one of the horses that drew Mars' chariot; also called an "attendant" or "son" of Mars, according to chapter 15, line 119 of Homer's "Iliad." This Greek word means "flight." August 17, 1877 A. Hall Mars II (Deimos) This outer Martian satellite was named for one of the horses that drew Mars' chariot; also called an "attendant" or "son" of Mars, according to chapter 15, line 119 of Homer's "Iliad." Deimos means "fear" in Greek. August 11, 1877 Selected Asteroids (of the Main Belt) and their Satellites Body Named for the Greek god of love. August 13, 1898 Named for a resort on the Crimean Peninsula. July 30, 1916 G. Neujmin (243) Ida Named for a nymph who raised the infant Zeus. Ida is also the name of a mountain on the island of Crete, the location of the cave where Zeus was reared. September 29, 1884 J. Palisa (243) Ida I (Dactyl) Named for a group of mythological beings who lived on Mount Ida, where the infant Zeus was hidden and raised (according to some accounts) by the nymph Ida. August 28, 1993 Galileo imaging and infrared science teams. (253) Mathilde The name was suggested by a staff member of the Paris Observatory who first computed an orbit for Mathilde. The name is thought to honor the wife of the vice director of the Paris Observatory at that time. November 12, 1885 J. Palisa (22) Kalliope I (Linus) Satellite of (22) Kalliope. In various accounts of Greek mythology, Linus is considered to be the son of the Muse Kalliope and the inventor of melody and rhythm. August 29 and September 2, 2001 Mauna Kea J.-L. Margot, M.E. Brown, W.J. Merline, F. Menard, L. Close, C. Dumas, C.R. Chapman, and D.C. Slater (45) Eugenia I (Petit-Prince) Satellite of (45) Eugenia. The Little Prince, Napolean-Eugene-Louis-Jean-Joseph Bonaparte (1856-1879), was the son of Eugenia de Montijo de Guzm\'an and Napoleon III. November 1, 1998 Mauna Kea W.J. Merline, L. Close, C. Dumas, C.R. Chapman, F. Roddier, F. Menard, D.C. Slater, G. Duvert, C. Shelton, and T. Morgan Jovian System Satellites in the Jovian system are named for Zeus/Jupiter's lovers and descendants. Names of outer satellites with a prograde orbit generally end with the letter "a" (although an "o" ending has been reserved for some unusual cases), and names of satellites with a retrograde orbit end with an "e." Body Discoverer Jupiter The largest and most massive of the planets was named Zeus by the Greeks and Jupiter by the Romans; he was the most important deity in both pantheons.     Jupiter I (Io) Io, the daughter

Visible sunspots vary in number according to a cycle of how many years?

Sunspots: Modern Research 4 of 7 The Sunspot Cycle Cycles have been around In the last few decades, we've started to understand the forces behind sunspots, but we've known for over a 150 years that sunspots appear in cycles. The average number of visible sunspots varies over time, increasing and decreasing on a regular cycle of between 9.5 to 11 years, on average about 10.8 years. An amateur astronomer named Heinrich Schwabe, was the first to note this cycle, in 1843. The part of the cycle with low sunspot activity is referred to as " solar minimum " while the portion of the cycle with high activity is known as " solar maximum ." In fact they go around twice By studying the sun's magnetic field, modern astronomers have discovered that the cycle covers twenty-two years, with each eleven-year cycle of sunspots followed by a reversal of the direction of the Sun's magnetic field. According to Fisher, "the overall magnetic field structure changes in a way that is very interesting. It turns out that if the magnetic fields primarily point from west to east in the Northern Hemisphere (of the sun), they point from east to west in the Southern Hemisphere. In the next eleven-year cycle, the fields are reversed. So the cycle is really twenty-two years." Migration Sunspots appear mostly in the low latitudes near the solar equator. In fact they almost never appear closer than 5 or further than 40 degrees latitude, north or south. As each sunspot cycle progresses, the sunspots gradually start to appear closer and closer to the equator. The sunspot locations for the most recent 11-year cycle are shown in this "butterfly" diagram." The locations "migrated" toward the equator (0 latitude) from both hemispheres throughout this half of the cycle.   Do sunspots affect earth's climate? From 1645 to 1715, there was a drastically reduced number of sunspots. This period of reduced solar activity, which was first noticed by G. Spörer, was later investigated by E.W. Maunder, is now called the Maunder Minimum . That the same period of time was also unusually cold on Earth.  Similar periods of low solar activity seem to have occurred during the Spörer Minimum (1420-1530), the Wolf Minimum (1280-1340), and the Oort minimum (1010-1050). This succession of low-temperature periods is now called the "Little Ice Age," and the corresponding pattern of extreme sunspot minima has led to speculation that sunspot activity may affect the earth's climate.

Which planet is usually the furthest form the Sun, but sometimes is not?

ASP: Pluto: The Farthest Planet (Usually) © 1988, Astronomical Society of the Pacific, 390 Ashton Avenue, San Francisco, CA 94112 Pluto: The Farthest Planet (Usually) Pluto, the ninth planet in our solar system, was not discovered until 1930 and remains a very difficult world to observe because it's so far away. At an average distance of 2.7 billion miles from the Earth, Pluto is a dim speck of light in even the largest of our telescopes. It takes almost 249 years to make one swing around the Sun, in a long looping orbit that takes it above and below the path of the other planets. (See the accompanying box for more on its unusual path.) What Would It Be Like on Pluto? While astronomers don't yet know many details about the landscape on Pluto, we do know that it's cold and dark out there. On average, Pluto is nearly 40 times as far from the Sun as we are. From that great distance, the Sun would look like a single, brilliant point of light (it would be only about 1/40th as big as the full Moon is in our sky — too small to appear as a disk.) During the day, that tiny point illuminates the ground on Pluto with only 1/1500th the intensity of sunlight we receive on Earth. (That's still far from being "dark,'' though: the Sun's light output as seen from Pluto is about 250 times the light we receive from the Moon when it's full.) As you might expect, Pluto isn't warmed much by the Sun; astronomers estimate its surface temperature to be more than 200 degrees below zero, Celsius. This is a temperature so cold that skin would be as brittle as glass — and that some materials we're familiar with as gas or Earth (such as methane) would freeze solid. New Discoveries in the Last Decade Despite its great distance, Pluto has given up some of its secrets to careful study recently. Even though no spacecraft has investigated Pluto (and none is scheduled to), a happy circumstance is in part responsible for the accelerating pace of discoveries: Pluto is closer to us in the last two decades of the 20th century than it has been for the last 200 years (or will be for the next 200). Along with the great sensitivity and sophistication of today's astronomical instruments, this makes investigating Pluto from Earth less difficult now. In 1978, for example, a relatively large satellite was discovered around Pluto and named Charon — and during the last half of the 1 980's, a rare alignment has made it possible to study Pluto and Charon much more effectively than ever before. For a brief period once every 124 years, observers on Earth are in a position to see Charon pass directly in front of and behind Pluto in its 6.4-day orbit around the planet. This "eclipse season'' began in 1985 and will end in 1990; there won't be another one until the 22nd century — and not until the 23rd century will one happen when Pluto is this close. By making careful measurements of the eclipses, astronomers have made great progress in understanding the sometimes strange and puzzling properties of Pluto and its satellite. Pluto is Not the Ninth Planet Ever since 1930, school children have memorized the nine planets in order: Mercury, Venus, Earth, Mars, Jupiter Saturn, Uranus, Neptune, and PIuto. But between January, 1979 and March, 1999 that order is not correct. Pluto's eccentric (ellipse-shaped) orbit has brought it inside the orbit of Neptune, making it the eighth planet for two decades. Pluto's unusual position makes "What is the ninth planet?'' a great trivia question for a while. Just in case students begin to worry that someday Pluto might collide with Neptune as the smaller planet crosses the orbit of the larger, you can reassure them. The two orbits are tilted relative to one another by 17 degrees) in such a way that they never actually "touch.'' (Imagine two enormous, slightly elongated hula hoops, one larger than the other. If the larger one is tilted relative to the smaller one, you can imagine that the two points where the larger hoop crosse

What was the name of the American mission to land a man on the Moon?

Apollo 11: First Men on the Moon Apollo 11: First Men on the Moon By Nola Taylor Redd, Space.com Contributor | July 25, 2012 03:39pm ET MORE Apollo 11 astronaut Edwin Aldrin photographed this iconic photo, a view of his footprint in the lunar soil, as part of an experiment to study the nature of lunar dust and the effects of pressure on the surface during the historic first manned moon landing in July 1969. Credit: NASA The historic launch of the Apollo 11 mission carried three astronauts toward the moon. Two of them would set foot on the lunar surface for the first time in human history as millions of people around the world followed their steps on television. The astronauts The crew of Apollo 11 were all experienced astronauts. All three had flown missions into space before. Cmdr. Neil Armstrong , 38, had previously piloted Gemini 8, the first time two vehicles docked in space. Born Aug. 5, 1930, in Ohio, Armstrong was 38 when he became the first civilian to command two American space missions. Apollo 11 crew: Neil Armstrong, Michael Collins and Edwin "Buzz" Aldrin. Credit: NASA Col. Edwin Eugene "Buzz" Aldrin , 39, was the first astronaut with a doctorate to fly in space. Born Jan. 20, 1930, in New Jersey, Aldrin piloted Gemini 12, taking a two-hour, twenty-minute walk in space to demonstrate that an astronaut could work efficiently outside of the vehicle. For Apollo 11, he served as the lunar module pilot. The command module pilot, Lt. Col. Michael Collins, 38, was born in Italy on Oct. 31, 1930. The pilot of Gemini 10, Collins spent almost an hour and a half outside of the craft on a space-walk and became the first person to meet another spacecraft in orbit. From Earth to the moon Mission planners at NASA studied the lunar surface for two years, searching for the best place to make the historic landing. Using high-resolution photographs taken by the Lunar Orbiter satellite and close-up photographs taken by the Surveyor spacecraft, they narrowed the initial thirty sites down to three. Influencing factors included the number of craters and boulders, few high cliffs or hills, and a relatively flat surface. The amount of sunlight was also a factor in determining the best time to land on the lunar surface. Apollo 11 launched from Kennedy Space Center in Florida at 9:32 a.m. EDT on July 16, 1969. While in flight, the crew made two televised broadcasts from the interior of the ship, and a third transmission as they drew closer to the moon, revealing the lunar surface and the intended approach path. On July 20, Armstrong and Aldrin entered the lunar module, nicknamed the "Eagle" and separated from the Command Service Module — the "Columbia" — headed toward the lunar surface. Apollo 11 astronaut Buzz Aldrin poses with the American flag on the surface of the moon in July 1969. Credit: NASA The lunar module touched down on the moon's Sea of Tranquility , a large basaltic region, at 4:17 p.m. EDT. Armstrong notified Houston with the historic words, "Houston, this is Tranquility Base. The Eagle has landed." For the first two hours, Armstrong and Aldrin checked all of the systems, configured the lunar module for the stay on the moon, and ate. They decided to skip the scheduled four-hour rest to explore the surface. A camera in the Eagle provided live coverage as Armstrong descended down a ladder at 11:56 p.m. on July 20, 1969, and uttered the words, "That's one small step for man, one giant leap for mankind." Aldrin followed twenty minutes later, with Armstrong recording his descent. Armstrong had the responsibility to document the landing, so most of the images taken from the Apollo 11 mission were of Aldrin. [Images: NASA's Historic Apollo 11 Moon Landing in Pictures ] While on the surface, the astronauts set up several experiments, collected samples of lunar soil and rock to bring home, erected a United States flag, and took core samples from the crust. They spoke with U.S. President Richard Nixon, whose voice was transmitted from the White House, and placed a plaque that stated: HERE MEN FROM THE PLANET EARTH FIRST SET FOOT

What was the name of the American space station?

Skylab: First U.S. Space Station Skylab: First U.S. Space Station By Elizabeth Howell, Space.com Contributor | February 1, 2013 06:40pm ET MORE The Skylab Orbital Workshop experienced a failure that led to a replacement shield to protect against solar heating. Credit: NASA. Skylab was the first space station operated by the United States. It spent six years orbiting Earth until its decaying orbit caused it to re-enter the atmosphere. It scattered debris over the Indian Ocean and sparsely settled areas of Western Australia. Three crews successfully lived on board the station for several months each. The last crew spent 84 days in orbit — an American record that stood until the shuttle era. [ Photos: Skylab, the 1st U.S. Space Station ] Rocky start Various NASA centers had kicked around ideas for a space station for years before Skylab launched. However, the agency was very focused on the space race and moonshots that dominated public consciousness in the 1960s. Money for other endeavors was not as available. As Apollo began to wind down in the early 1970s, NASA began an Apollo Applications Program to fly unused hardware from the moon program. One idea, proposed by famous Apollo rocket engineer Wernher von Braun , would be to build a space station out of an unused rocket stage. The design evolved over the years as NASA struggled with reduced funding. Skylab finally aimed for space on May 14, 1973. However, a meteoroid shield that was supposed to shelter Skylab accidentally opened about 63 seconds into the launch. The still-thick atmosphere tore the shield off, plunging Skylab into a serious situation. The facility experienced communications problems with the antenna as a result of the incident, but that was the least of the agency's worries. "When the meteoroid shield ripped loose, it disturbed the mounting of workshop solar array wing No. 2 and caused it to partially deploy. The exhaust plume of the second stage retro-rockets impacted the partially deployed solar array and literally blew it into space," NASA wrote. Workers at NASA's Marshall Space Flight Center scrambled to stabilize the station. Among other measures, they put the station in an attitude that would minimize overheating, and came up with ways to cope with the station's reduced power situation. Meanwhile, the first crew – led by Apollo 12 commander Pete Conrad – would need to make the station habitable before they could get to work. The crew's first challenge during the spacewalk, just hours after launch, was deploying the solar array, but initial attempts met with no luck as a metal strip holding it down refused to give way. Crew members emerged from an expected communications blackout in a foul mood, according to an official NASA account of the mission. "The astronauts were venting their frustration with four-letter words, while Houston repeatedly tried to remind them that communication had resumed," NASA wrote. Realizing the tools they had with them that day would not work, Conrad abandoned the exercise and focused on trying to dock his spacecraft with the station. Unfortunately, the docking mechanism failed and the crew had to depressurize the spacecraft and bypass electrical connections to achieve it. In subsequent days, Conrad's crew erected a sun shade , successfully deployed the stuck array, and began operational work aboard the station. While the incident was frustrating for the teams involved, it also demonstrated that it was possible to fix a badly damaged space station while it is in orbit. Cutaway view of Skylab

Which country built the Saturn V rocket?

Saturn V Launch Vehicle | National Air and Space Museum Saturn V Launch Vehicle Saturn V Launch Vehicle Saturn V Launch Vehicle The manned Apollo missions were each launched aboard a Saturn V launch vehicle. The "V" designation originates from the five powerful F-1 engines that powered the first stage of the rocket. The Saturn V remains the largest and most powerful U.S. expendable launch vehicle ever built. The Apollo spacecraft, including the Command Module (CM), Service Module (SM) and Lunar Module (LM) sat atop the launch vehicle. Above the CM was the emergency escape system. The complete assembly including the Apollo spacecraft and the Saturn launch vehicle stood 363 feet tall (110.6 meters) and weighed over 6 million pounds (2.7 million kg). The Saturn V launch vehicle itselft consisted of three stages: First Stage (S-IC): The first stage includes the five F-1 engines producing nearly 7.7 million pounds of thrust. These powerful engines are required to lift the heavy rocket fast enough to escape Earth's gravity. The first stage engines are burned at liftoff and last for about 2.5 minutes taking the vehicle and payload to an altitude of 38 miles. The first stage then separates and burns up in the Earth's atmosphere. Second Stage (S-II): The second stage conatins five J-2 engines. After the first stage is discarded, the second stage burns for approximately 6 minutes taking the vehicle and payload to 115 miles altitude. The second stage is then also discarded. Third Stage (S-IVB): The third stage contains one J-2 engine. This engine burns for 2.75 minutes boosting the spacecraft to orbital velocity of about 17,500 mph. The third stage is shut down with fuel remaining and remains attached the spacecraft in Earth orbit. The J-2 engine is reignited to propel the spacecraft into translunar trajectory (speed of 24,500 mph) before finally being discarded. Saturn V Rocket

Which objects in space emit energy in pulses?

Pulsars - Celestial Objects on Sea and Sky Pulsars Pulsars Cosmic Beacons Pulsars are among the strangest objects in the universe. In 1967, at the Cambridge Observatory, Jocelyn Bell and Anthony Hewish were studying the stars when they stumbled on something quite extraordinary. It was a star-like object that seemed to be emitting quick pulses of radio waves. Radio sources had been known to exist in space for quite some time. But this was the first time anything had been observed to give off such quick pulses. They were as regular as clockwork, pulsing once every second. The signal was originally thought to be coming from an orbiting satellite, but that idea was quickly disproved. After several more of these objects had been found, they were named pulsars because of their rapidly pulsing nature. Bright pulsars have been observed at almost every wavelength of light. Some can actually be seen in visible light. Many people tend to get pulsars confused with quasars. But the two objects are totally different. Quasars are objects that produce enormous amounts of energy and may be the result of a massive black hole at the center of a young galaxy. But a pulsar is a different animal entirely. The Lighthouse Effect A pulsar is basically a rapidly spinning neutron star. A neutron star is the highly compacted core of a dead star, left behind in a supernova explosion. This neutron star has a powerful magnetic field. In fact, this magnetic field is about one trillion times as powerful as the magnetic field of the Earth. The magnetic field causes the neutron star to emit strong radio waves and radioactive particles from its north and south poles. These particles can include a variety of radiation, including visible light. Pulsars that emit powerful gamma rays are known as gamma ray pulsars. If the neutron star happens to be aligned so that the poles face the Earth, we see the radio waves every time one of the poles rotates into our line of sight. It is a similar effect as that of a lighthouse. As the lighthouse rotates, its light appears to a stationary observer to blink on and off. In the same way, the pulsar appears to be blinking as its rotating poles sweep past the Earth. Different pulsars pulse at different rates, depending on the size and mass of the neutron star. Sometimes a pulsar may have a binary companion. In some cases, the pulsar may begin to draw in matter from this companion. this can cause the pulsar to rotate even faster. The fastest pulsars can pulse at well over a hundred times a second. Pulsars & Neutron Stars A pulsar is formed when a massive star collapses exhausts its supply of fuel. It blasts out in a giant explosion known as a supernova, the most powerful and violent event in the universe. Without the opposing force of nuclear fusion to balance it, gravity begins to pull the mass of the star inward until it implodes. In a pulsar, gravity compacts the mass of the star until it forms an object composed primarily of neutrons packed so tightly that they no longer exist as normal matter. A physicist named Chandrasekhar Subrahmanyan theorized that if the mass of the core of the collapsing star was 1.4 times the mass of the star itself, the protons and electrons would combine to form neutrons in a neutron star. This number is known today as the Chandrasekhar limit. If this limit is not achieved by the collapsing core, a white dwarf star will be produced instead. If the limit is much greater, a black hole may be the result. As the star collapses, it begins to spin more rapidly in what is known as the conservation of angular momentum. The process is similar to that of an ice skater pulling their arms in close to spin faster. What is left behind is a rapidly spinning ball of tightly packed neutrons inside an iron shell. The extreme force of gravity would cause this shell to be extremely smooth and shiny. The resulting neutron star is only about 20 miles in diameter, yet is contains most of the mass of the original star it was formed from. The matter in this neutron star is packed so tightly that a piece the size of a sug

What travels around the Sun at an average speed of 185 miles per second.

At what speed does the Earth move around the Sun? (Beginner) - Curious About Astronomy? Ask an Astronomer At what speed does the Earth move around the Sun? (Beginner) Short version: Earth's average orbital speed is about 30 kilometers per second. In other units, that's about 19 miles per second, or 67,000 miles per hour, or 110,000 kilometers per hour (110 million meters per hour). In more detail: Let's calculate that. First of all we know that in general, the distance you travel equals the speed at which you travel multiplied by the time (duration) of travel. If we reverse that, we get that the average speed is equal to the distance traveled over the time taken. We also know that the time it takes for the Earth to go once around the Sun is one year. So, in order to know the speed, we just have to figure out the distance traveled by the Earth when it goes once around the Sun. To do that we will assume that the orbit of the Earth is circular (which is not exactly right, it is more like an ellipse , but for our purpose a circle is close enough). So the distance traveled in one year is just the circumference of the circle. (Remember, the circumference of a circle is equal to 2×π×radius.) The average distance from the Earth to the Sun is about 149,600,000 km. (Astronomers call this an astronomical unit, or AU for short.) Therefore, in one year, the Earth travels a distance of 2×π×(149,600,000 km). This means that the speed is about: speed = 2×π×(149,600,000 km)/(1 year) and if we convert that to more meaningful units (knowing that there are, on average, about 365.25 days in a year, and 24 hours per day) we get: speed = 107,000 km/h (or, if you prefer, 67,000 miles per hour) So the Earth moves at about 110,000 km/h around the Sun (which is about one thousand times faster than the typical speed of a car on a highway!) Thanks for your explanation, but I was hoping for an explanation a little more precise, since I already knew the one you gave. In the case of your question about the speed of the Earth around the Sun, there isn't really a more 'precise' answer. The only approximation I did in the calculation I sent you is assuming that the orbit of the Earth is circular. This is in fact a very good approximation. One of Kepler's laws describing planetary motions states that all orbits are ellipses. This is the case for Earth's orbit. But not all ellipses come in the same shape. They are described by their 'eccentricity', which tells us how flattened they are. The eccentricity  of an ellipse is a number that varies between 0 and 1, 0 being a perfect circle, and close to 1 being a very flattened ellipse. It turns out that the orbit of the Earth right now has an eccentricity of about 0.017. This means it is almost a circle, making our approximation valid. So under the one approximation that was made, the calculation couldn't really be more 'precise'. And as for the average Earth-Sun distance, the true value changes slightly over time due to gravitational perturbations from the other planets, so there really isn't much point in using a more precise value than the one given above. Now if you want to calculate the speed of the Earth on its orbit without assuming it is a circle, it is another ball game! First of all, I cannot give you a precise answer, because the speed of the Earth changes all the time as the Earth moves around the Sun. This is because Kepler's second law says that on its orbit, a planet will sweep equal areas in equal amounts of time. This means that when the Earth is closer to the Sun (which happens in early January, about two weeks after the northern winter solstice) it's moving faster than when it is farther away. (For more information on how the Earth's orbital speed varies over the course of a year, please see this answer .) Unless you specified a certain date, this means I cannot give you a precise value for the speed of the Earth assuming its orbit is an ellipse. We are better off to stick with the first number we got - the average speed. I hope this answers your question now! This page was last updated on Febr

Which is the second lightest element in the universe?

Where is Helium Found - Universe Today   Universe Today by Tega Jessa [/caption] Helium is the second lightest element in the known universe. It is also the second most abundant. According to some estimates helium accounts for as much as 24 percent of the Universe’s mass. This element is also plentiful since it is a prime product of fusion nuclear reactions involving hydrogen. So if it is so plentiful where is Helium found? The problem is that just because an element is common in the universe at large does not mean that it is common on Earth. Helium is an element that fits this scenario. Helium only accounts for 0.00052% of the Earth’s atmosphere and the majority of the helium harvested comes from beneath the ground being extracted from minerals or tapped gas deposits. This makes it one of the rarest elements of any form on the planet. Like mentioned before Helium is rare on Earth but there are places where it is readily found. If you look at space the majority of helium is in stars and the interstellar medium. This is due to the fusion reaction that powers most stars fusing single hydrogen atoms to create helium atoms. This process balanced with a star’s gravity is what helps it to stay stable for billions of years. On Earth the majority of helium found comes from radioactive decay. This is the opposite nuclear reaction called fission that splits atoms. For this reason radioactive minerals in the lithosphere like uranium are prime sources for helium. On Earth there are key locations where concentrated helium can be harvested. The United States produces the majority of the world’s helium supply at 78%. The rest of the world’s helium is harvested in North Africa, The Middle East, and Russia. The interesting thing is that thanks to these deposits the world’s demand for helium is being met regularly. Also unlike petroleum which can decades to form from organic material, 3000 metric tons of Hydrogen is produced yearly. Until helium demand reaches at least the same level of demand as petroleum there it little chance of that demand outpacing supply. Helium is looking to be a major player in the near future. Governments are looking into using the gas as source of hydrogen for fuel cells and other transportation technologies. At the moment the promise is still tentative but at least with better surveying and knowledge of gas deposits there will be a supply waiting if becomes the next major element to power human civilization. In the meanwhile ours is still a planet beholden to carbon. We have written many articles about Helium for Universe Today. Here’s an article about the discovery of Helium , and here’s an article about composition of the Sun . If you’d like more info about helium on Earth, check out NASA’s Solar System Exploration Guide on Earth . And here’s a link to NASA’s Earth Observatory . We’ve also recorded an episode of Astronomy Cast all about planet Earth. Listen here, Episode 51: Earth .

What is the name of the thousands of small bodies which orbit the Sun?

Small Solar-System Bodies  l Small Bodies News Small Solar-System Bodies The title The Nine Planets is somewhat misleading. In addition to the (eight) planets and their satellites the solar system contains a large number of smaller but interesting objects. Small Bodies There are thousands of known asteroids and comets and undoubtedly many more unknown ones. Most asteroids orbit between Mars and Jupiter . A few (e.g. 2060 Chiron) are farther out. There are also some asteroids whose orbits carry them closer to the Sun than the Earth (Aten, Icarus, Hephaistos). Most comets have highly elliptical orbits which spend most of their time in the outer reaches of the solar system with only brief passages close to the Sun. And there is a large and important class of Trans-Neptunian Objects or Kuiper Belt Objects (including Pluto) that orbit (mostly) beyond Neptune. The distinction between comets and asteroids is somewhat controversial . The main distinction seems to be that comets have more volatiles and more elliptical orbits. But there are interesting ambiguous cases such as 2060 Chiron (aka 95 P/Chiron) and 3200 Phaethon which seem to share some aspects of both categories. Asteroids are sometimes also referred to as minor planets or planetoids (not to be confused with "lesser planets" which refers to Mercury and Pluto ). Some of the largest asteroids and Kuiper Belt objects may be classified as dwarf planets. Very small rocks orbiting the Sun are sometimes called meteoroids to distinguish them from the larger asteroids. When such a body enters the Earth's atmosphere it is heated to incandescence and the visible streak in the sky is known as a meteor. If a piece of it survives to reach the Earth's surface it is known as a meteorite. Millions of meteors bright enough to see strike the Earth every day (amounting to hundreds of tons of material). All but a tiny fraction burn up in the atmosphere before reaching the ground. The few that don't are our major source of physical information about the rest of the solar system. Finally, the space between the planets is not empty at all. It contains a great deal of microscopic dust and gas as well as radiation and magnetic fields.

What can contract to give birth to a star?

Stars | Science Mission Directorate Science Mission Directorate Exoplanets Stars Stars are the most widely recognized astronomical objects, and represent the most fundamental building blocks of galaxies. The age, distribution, and composition of the stars in a galaxy trace the history, dynamics, and evolution of that galaxy. Moreover, stars are responsible for the manufacture and distribution of heavy elements such as carbon, nitrogen, and oxygen, and their characteristics are intimately tied to the characteristics of the planetary systems that may coalesce about them. Consequently, the study of the birth, life, and death of stars is central to the field of astronomy. Star Formation Stars are born within the clouds of dust and scattered throughout most galaxies. A familiar example of such as a dust cloud is the Orion Nebula. Turbulence deep within these clouds gives rise to knots with sufficient mass that the gas and dust can begin to collapse under its own gravitational attraction. As the cloud collapses, the material at the center begins to heat up. Known as a protostar, it is this hot core at the heart of the collapsing cloud that will one day become a star. Three-dimensional computer models of star formation predict that the spinning clouds of collapsing gas and dust may break up into two or three blobs; this would explain why the majority the stars in the Milky Way are paired or in groups of multiple stars. The observations of Eta Carinae's light echo are providing new insight into the behavior of powerful massive stars on the brink of detonation. Credit: NOAO, AURA, NSF, and N. Smith (University of Arizona) As the cloud collapses, a dense, hot core forms and begins gathering dust and gas. Not all of this material ends up as part of a star — the remaining dust can become planets, asteroids, or comets or may remain as dust. In some cases, the cloud may not collapse at a steady pace. In January 2004, an amateur astronomer, James McNeil, discovered a small nebula that appeared unexpectedly near the nebula Messier 78, in the constellation of Orion. When observers around the world pointed their instruments at McNeil's Nebula , they found something interesting — its brightness appears to vary. Observations with NASA's Chandra X-ray Observatory provided a likely explanation: the interaction between the young star's magnetic field and the surrounding gas causes episodic increases in brightness. Main Sequence Stars A star the size of our Sun requires about 50 million years to mature from the beginning of the collapse to adulthood. Our Sun will stay in this mature phase (on the main sequence as shown in the Hertzsprung-Russell Diagram) for approximately 10 billion years. Stars are fueled by the nuclear fusion of hydrogen to form helium deep in their interiors. The outflow of energy from the central regions of the star provides the pressure necessary to keep the star from collapsing under its own weight, and the energy by which it shines. As shown in the Hertzsprung-Russell Diagram, Main Sequence stars span a wide range of luminosities and colors, and can be classified according to those characteristics. The smallest stars, known as red dwarfs, may contain as little as 10% the mass of the Sun and emit only 0.01% as much energy, glowing feebly at temperatures between 3000-4000K. Despite their diminutive nature, red dwarfs are by far the most numerous stars in the Universe and have lifespans of tens of billions of years. On the other hand, the most massive stars, known as hypergiants, may be 100 or more times more massive than the Sun, and have surface temperatures of more than 30,000 K. Hypergiants emit hundreds of thousands of times more energy than the Sun, but have lifetimes of only a few million years. Although extreme stars such as these are believed to have been common in the early Universe, today they are extremely rare - the entire Milky Way galaxy contains only a handful of hypergiants. Stars and Their Fates In general, the larger a star, the shorter its life, although all but the most massive stars live for billions o

What is the name for the study of the structure of the universe?

WMAP's Introduction to Cosmology Related Topics Cosmology: The Study of the Universe Cosmology is the scientific study of the large scale properties of the universe as a whole. It endeavors to use the scientific method to understand the origin, evolution and ultimate fate of the entire Universe. Like any field of science, cosmology involves the formation of theories or hypotheses about the universe which make specific predictions for phenomena that can be tested with observations. Depending on the outcome of the observations, the theories will need to be abandoned, revised or extended to accommodate the data. The prevailing theory about the origin and evolution of our Universe is the so-called Big Bang theory. Choose from the links in the left column for discussed at length. This primer in cosmological concepts is organized as follows: The main concepts of the Big Bang theory are introduced in the first section with scant regard to actual observations. The second section discusses the classic tests of the Big Bang theory that make it so compelling as the most likely valid and accurate description of our universe. The third section discusses observations that highlight limitations of the Big Bang theory and point to a more detailed model of cosmology than the Big Bang theory alone provides. As discussed in the first section, the Big Bang theory predicts a range of possibilities for the structure and evolution of the universe. The final section discusses what constraints we can place on the nature of our universe based on current data, and indicates how WMAP furthers our understanding of cosmology. In addition, a few related topics are discussed based on commmonly asked questions. For purposed of citation of this portion of the site or the downloadable PDF you can use this information: WMAP Science Team, "Cosmology: The Study of the Universe," NASA's Wilkinson Microwave Anisotropy Probe,last modified June 6, 2011, http://map.gsfc.nasa.gov/universe/WMAP_Universe.pdf or http://map.gsfc.nasa.gov/universe/

What units are used for measuring distances in the universe?

Units for Distance and Size in the Universe | Las Cumbres Observatory Space Book Units for Distance and Size in the Universe Astronomers use many of the same units of measurement as other scientists. They often use meters for length, kilograms for mass, and seconds for time. However, the distances and sizes in the universe can be so big, that astronomers have invented more units to describe distance. Astronomical Units: Distances in the solar system are often measured in astronomical units (abbreviated AU). An astronomical unit is the average distance between the Earth and the Sun: 1 AU = 1.496 × 108 km = 93 million miles Jupiter is about 5.2 AU from the Sun and Pluto is about 39.5 AU from the Sun. The distance from the Sun to the center of the Milky Way is approximately 1.7 × 109 AU. Light-Years: To measure the distances between stars, astronomers often use light-years (abbreviated ly). A light-year is the distance that light travels in a vacuum in one year: 1 ly = 9.5 × 1012 km = 63,240 AU Proxima Centauri is the nearest star to Earth (other than the Sun) and is 4.2 light-years away. This means light from Proxima Centauri takes 4.2 years to travel to Earth. Parsecs: Many astronomers prefer to use parsecs (abbreviated pc) to measure distance to stars. This is because its definition is closely related to a method of measuring the distances between stars. A parsec is the distance at which 1 AU subtends and angle of 1 arcsec. 1 pc = 3.09 × 1013 km = 3.26 ly    For even greater distances, astronomers use kiloparsecs and megaparsecs (abbreviated kpc and Mpc). 1 kiloparsec = 1 kpc = 1000 pc = 103 pc 1 megaparsec = 1 Mpc = 1,000,000 pc = 106 pc Powers of Ten: The distances and sizes of of the objects astronomers study vary from very small, including atoms and atomic nuclei, to very large including galaxies, clusters of galaxies and the size of the universe. To describe such a huge range, astronomers need a way to avoid confusing terms like "a billion trillion" and "a millionth". Astronomers use a system called powers-of-ten notation, which consolidates all of the zeros that you would normally find attached to very large or small numbers such as 1,000,000,000,000 or 0.0000000001. All of the zeros are put in an exponent, which is written as a superscript, and indicates how many zeros you would need to write out the long form of the number. So for example: 100 = 1 104 = 10,000 and so on. In powers-of-ten notation, numbers are written as a figure between one and ten multiplied by a power of ten. So for example, the distance to the Moon of 384,000 km can be re-written as 3.84 × 105 km. Notice that 3.84 is between one and ten. The same number could accurately be rewritten as 38.4 × 104 or 0.384 × 106, but the preferred form is to have the first number be between one and ten. Very small numbers can also be written using powers-of-ten notation. The exponent is negative for numbers less than one and indicates dividing by that number of tens. So for example: 100 = 1

What is another name for a shooting or falling star?

What is a Shooting Star? - Universe Today   Universe Today What is a Shooting Star? Article Updated: 24 Dec , 2015 by Fraser Cain A shooting star is another name for a meteoroid that burns up as it passes through the Earth’s atmosphere. So, a shooting star isn’t a star at all. Most of the shooting stars that we can see are known as meteoroids. These are objects as small as a piece of sand, and as large as a boulder. Smaller than a piece of sand, and astronomers call them interplanetary dust. If they’re larger than a boulder, astronomers call them asteroids. A meteoroid becomes a meteor when it strikes the atmosphere and leaves a bright tail behind it. The bright line that we see in the sky is caused by the ram pressure of the meteoroid. It’s not actually caused by friction, as most people think. When a meteoroid is larger, the streak in the sky is called a fireball or bolide. These can be bright, and leave a streak in the sky that can last for more than a minute. Some are so large they even make crackling noises as they pass through the atmosphere. If any portion of the meteoroid actually survives its passage through the atmosphere, astronomers call them meteorites. Some of the brightest and most popular meteor showers are the Leonids, the Geminids, and the Perseids. With some of these showers, you can see more than one meteor (or shooting star) each minute.

What is the Latin name for the North Star?

North Star - definition of North Star by The Free Dictionary North Star - definition of North Star by The Free Dictionary http://www.thefreedictionary.com/North+Star (Celestial Objects) the North Star another name for Polaris 1 Po•lar•is (poʊˈlɛər ɪs, -ˈlær-, pə-) n. the polestar or North Star, a star of the second magnitude situated close to the north pole of the heavens, in the constellation Ursa Minor: the outermost star in the handle of the Little Dipper. [1955–60; short for Medieval Latin stella polāris polar star] North Star Noun 1. North Star - the brightest star in Ursa Minor; at the end of the handle of the Little Dipper; the northern axis of the earth points toward it polar star , Polaris , pole star , polestar Little Bear , Ursa Minor - a constellation outside the zodiac that rotates around the North Star Little Dipper , Dipper - a cluster of seven stars in Ursa Minor; at the end of the dipper's handle is Polaris North Star noun Pole Star , Polaris , lodestar I could see the Bear and had identified the North Star. Translations North Star n the North Star → la stella polare Want to thank TFD for its existence? Tell a friend about us , add a link to this page, or visit the webmaster's page for free fun content . Link to this page: References in classic literature ? He pointed to where the North Star burned over the Khyber Pass. Little Mildred answered nothing, but watched the North Star and hummed a selection from recent Simla burlesque that had much delighted the White Hussars. View in context said the scout, shaking his head doubtingly; "When the sun is scorching the tree tops, and the water courses are full; when the moss on every beech he sees will tell him in what quarter the north star will shine at night. View in context And first, as soon as it began to be dark, we kindled a fire in our little camp, which we kept burning, and prepared so as to make it burn all night, that the Tartars might conclude we were still there; but as soon as it was dark, and we could see the stars (for our guide would not stir before), having all our horses and camels ready loaded, we followed our new guide, who I soon found steered himself by the north star, the country being level for a long way. 'Living wage' is helping The acquisition underscores [our] continued commitment to providing quality service and high quality block, brick, landscape, and contractor supply products to the southern Minnesota and northern Iowa markets," says North Star Regional Manager Chad Grande. Already a key source of clay brick, concrete block and retaining wall units, natural stone veneers and landscaping materials, North Star Stone & Masonry has extended its southern Minnesota footprint by acquiring the Superior Concrete Block Co. plant in Mankato, southwest of the Twin Cities North Star is gratified that the Board has made a change of the Chairman position, but this change falls far short of addressing the pro-shareholder corporate governance initiatives North Star has continuously sought, including elimination of the classified board and adding shareholder nominated directors to the Board.

Scientists study the red shift to investigate which aspect of cosmology?

An Introduction to Philosophy and Cosmology What is Cosmology? written by: Jason C. Chavis•edited by: RC Davison •updated: 7/30/2011 Cosmology is the study of the Universe and man's place within it. Human existence is intertwined with the understanding and existence of the Universe. Cosmology attempts to analyze this connection between what we know to be true and what we believe in. Science, religion and philosophy play a role. slide 1 of 7 How Cosmology Fits with Science Cosmology is the study of the Universe and humanity's place within it. The study has a long history, rooted in region, science, philosophy and esotericism. The first use of the definition was by Christian Wolff, a German philosopher who wrote Comologia Generalis in 1730. The term is derived from the Greek kosmos, meaning “universe," and logia, meaning “study." Modern cosmology is an extension of physics and astrophysics. As the studies showed to play a central role in the fundamental understanding of the Universe, the two sciences became synonymous with cosmology . Mathematics and observational elements began to define the limits and expanses of the Universe as a whole. Scientist were able to understand the concept of the big bang and hypothesize about the expansion of space, determining that the Universe formed 13.7 billion years ago. These discoveries led to the establishment of certain physical laws that exist today, and logically have always existed. Roger Bacon, persecuted by the Catholic Church, postulated during the 1200s the idea of a universe not centered around humans. This drew a stark contrast between religion and science. Cosmology attempts to not only decipher the true nature of the Universe, but also man's place within its boundaries. This has led to the creation of a specific discipline within the cosmology field known as metaphysical cosmology. It attempts to answer the questions regarding natural boundaries and where the human being lies. It can also make determinations about God as a concept within the spacial construct of the Universe. Ancient religions were tandem to the early studies of cosmology. Mythologizing and theorizing about the creation of the Universe, man's place and the ultimate destruction. slide 2 of 7 slide 3 of 7 Above: Ancient woodcarving of where heaven and earth meet. (Image credit: Heikenwaelder Hugo at Wikimedia Commons, http://en.wikipedia.org/wiki/File:Universum.jpg, Creative Commons Attribution ShareAlike 2.5.) slide 4 of 7 Science The establishment of the large scale nature of the Universe was one of the first successes of the early cosmologists. Ptolemy, an ancient Greek mathematician, proposed the theory that the Earth was the center of the Universe and all things flow around it. This model was called the geocentric system and stayed as the preferred truth about the Universe until the 16th century. Nicolaus Copernicus authored a book entitled On the Evolution of Celestial Spheres in which he claimed the Earth was not the center of the Universe and it orbited around the Sun. This made the Sun the center of the Universe and this was called the heliocentric system. Subsequent studies made by Johannes Kepler and Galileo Galilei also supported this theory. However, critics of this idea questioned why the celestial bodies floated around the Sun. It wasn't until Isaac Newton established the law of universal gravitation that humans understood the principles that made the solar system function -- gravity was the cause of all motion. During the 1900s, scientists like Albert Einstein pushed for greater understanding of the Universe. The Great Debate, a meeting of the U.S. National Academy of Sciences in Washington on August 26, 1920, established the modern principles that scientists follow today. The center of the debate was whether the Milky Way star system was the only true system and everything else orbited around it. Harlow Wilson was the champion of this theory, while Herber D. Curtis claimed that spiral nebulae were their own system, essentially island universes. Edwin Hubble solved the question by showing that

Which planet possesses the Galilean satellites?

Photos: The Galilean Moons of Jupiter Photos: The Galilean Moons of Jupiter By SPACE.com | June 14, 2013 06:49am ET MORE Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute Introduction 67 moons orbit the great gas giant Jupiter; of these, the four largest are known as the Galilean moons, having been discovered by Galileo Galilei using his telescope in 1610. The four moons are Io, Europa, Ganymede, and Callisto, in order of distance from Jupiter. (Their names derive from lovers of Zeus.) These moons provided evidence that not all celestial bodies orbit the Earth, a powerful revelation as, up until that time, astronomers considered Earth the center of the universe. [See Jupiter’s Moons reference page for more information.] First: Io Credit: NASA/JPL/University of Arizona Io Io orbits closest to Jupiter, out of the four Galilean moons. Io has been studied by spacecraft from Pioneer 10 and 11 in 1973 and 1974, all the way up to New Horizons in 2007, augmented by Earth- and space-based telescopes. This satellite possesses volcanoes, the only celestial body in the solar system other than Earth known to harbor volcanic activity. In fact, Io represents the most geologically active object in the solar system. Io contains an iron or iron sulfide core and a brown silicate outer layer, producing colorful orange, yellow, black, red, and white patches on the surface. Io also possesses sulfur dioxide snowfields, covering much of its surface. [See more information about Io .] Next: Europa Credit: NASA/JPL/University of Arizona Europa Europa, slightly smaller than Earth’s moon, represents one of the largest bodies in the solar system, though smaller than the other Galilean satellites of Jupiter. Cracks and streaks mark the entirety of the icy surface, which contains few craters, as the shiny, smooth skin of the moon only dates back 20 to 180 million years, a youthful age. Researchers speculate that a liquid water ocean lies beneath the ice. [See more information about Europa .] Next: Ganymede Credit: NASA Ganymede Ganymede, the third Gallilean moon, looms larger than the others. It compares in size to Mercury, but possesses about half the mass of that planet. Ganymede distinguishes itself from the other Galilean moons by possessing its own magnetic field. A thick crust of mostly ice wraps around the satellite’s iron core. Highly cratered dark regions cover 40 percent of Ganymede’s surface, while the remaining 60 percent hosts a light grooved terrain, forming intricate patterns on that moon. [See more information about Ganymede .] Next: Callisto Credit: NASA Callisto Callisto, the fourth Galilean moon, farthest from Jupiter, represents the most heavily cratered object in the solar system. The moon’s landscape remains largely unchanged since the time of its formation, attracting much interest from researchers. Callisto roughly approximates Mercury in size, but the moon possesses a lower density. It also experiences the least amount of effect from Jupiter’s magnetic field, as it orbits farther away from the planet, beyond Jupiter’s primary radiation belt. [See more information about Callisto .] 6 of 6

What is brighter than a hundred million suns?

Brighter Than 200 Million Suns Imagining and Planning Interstellar Exploration Brighter Than 200 Million Suns by Paul Gilster on September 2, 2004 It looks bright enough to be a foreground star, but this supernova, called SN 2004dj, is 11 million light years away in a galaxy known as NGC 2403. Not particularly germane to interstellar propulsion or finding candidates for robotic probes, but simply too remarkable a sight to ignore. You can read more about this Hubble photograph here . From the press release issued by the Space Telescope Science Institute: The heart of NGC 2403 is the glowing region at lower left. Sprinkled across the region are pink areas of star birth. The myriad of faint stars visible in the Hubble image belong to NGC 2403, but the handful of very bright stars in the image belong to our own Milky Way Galaxy and are only a few hundred to a few thousand light-years away. This image was taken on Aug. 17, two weeks after an amateur astronomer discovered the supernova. What we’re seeing here is the creation of heavy chemical elements like calcium, iron and gold, all of which, on Earth and elsewhere, came from explosions like this one. Charter In Centauri Dreams, Paul Gilster looks at peer-reviewed research on deep space exploration, with an eye toward interstellar possibilities. For the last nine years, this site has coordinated its efforts with the Tau Zero Foundation , and now serves as the Foundation's news forum. In the logo above, the leftmost star is Alpha Centauri, a triple system closer than any other star, and a primary target for early interstellar probes. To its right is Beta Centauri (not a part of the Alpha Centauri system), with Beta, Gamma, Delta and Epsilon Crucis, stars in the Southern Cross, visible at the far right (image: Marco Lorenzi ). Now Reading

Saturn's ring has how many sections?

How many rings does Saturn have? | Cool Cosmos   How many rings does Saturn have? Saturn has four main groups of rings and three fainter, narrower ring groups. These groups are separated by gaps called divisions. Close up views of Saturn's rings by the Voyager spacecrafts, which flew by them in 1980 and 1981, showed that these seven ring groups are made up of thousands of smaller rings. The exact number is not known. Continue the conversation on

What was the name of two space probes launched in 1977 which sent back remarkable pictures of Jupiter, Saturn, Uranus and Neptune?

Voyager - Planetary Voyage   Planet montage (left to right), Neptune, Uranus, Saturn, Jupiter The twin spacecraft Voyager 1 and Voyager 2 were launched by NASA in separate months in the summer of 1977 from Cape Canaveral, Florida. As originally designed, the Voyagers were to conduct closeup studies of Jupiter and Saturn, Saturn's rings, and the larger moons of the two planets. To accomplish their two-planet mission, the spacecraft were built to last five years. But as the mission went on, and with the successful achievement of all its objectives, the additional flybys of the two outermost giant planets, Uranus and Neptune, proved possible -- and irresistible to mission scientists and engineers at the Voyagers' home at the Jet Propulsion Laboratory in Pasadena, California. As the spacecraft flew across the solar system, remote-control reprogramming was used to endow the Voyagers with greater capabilities than they possessed when they left the Earth. Their two-planet mission became four. Their five-year lifetimes stretched to 12 and is now near thirty-seven years. Eventually, between them, Voyager 1 and 2 would explore all the giant outer planets of our solar system, 48 of their moons, and the unique systems of rings and magnetic fields those planets possess. Had the Voyager mission ended after the Jupiter and Saturn flybys alone, it still would have provided the material to rewrite astronomy textbooks. But having doubled their already ambitious itineraries, the Voyagers returned to Earth information over the years that has revolutionized the science of planetary astronomy, helping to resolve key questions while raising intriguing new ones about the origin and evolution of the planets in our solar system. History Of The Voyager Mission The Voyager mission was designed to take advantage of a rare geometric arrangement of the outer planets in the late 1970s and the 1980s which allowed for a four-planet tour for a minimum of propellant and trip time. This layout of Jupiter, Saturn, Uranus and Neptune, which occurs about every 175 years, allows a spacecraft on a particular flight path to swing from one planet to the next without the need for large onboard propulsion systems. The flyby of each planet bends the spacecraft's flight path and increases its velocity enough to deliver it to the next destination. Using this "gravity assist" technique, first demonstrated with NASA's Mariner 10 Venus/Mercury mission in 1973-74, the flight time to Neptune was reduced from 30 years to 12. While the four-planet mission was known to be possible, it was deemed to be too expensive to build a spacecraft that could go the distance, carry the instruments needed and last long enough to accomplish such a long mission. Thus, the Voyagers were funded to conduct intensive flyby studies of Jupiter and Saturn only. More than 10,000 trajectories were studied before choosing the two that would allow close flybys of Jupiter and its large moon Io, and Saturn and its large moon Titan; the chosen flight path for Voyager 2 also preserved the option to continue on to Uranus and Neptune. From the NASA Kennedy Space Center at Cape Canaveral, Florida, Voyager 2 was launched first, on August 20, 1977; Voyager 1 was launched on a faster, shorter trajectory on September 5, 1977. Both spacecraft were delivered to space aboard Titan-Centaur expendable rockets. The prime Voyager mission to Jupiter and Saturn brought Voyager 1 to Jupiter on March 5, 1979, and Saturn on November 12, 1980, followed by Voyager 2 to Jupiter on July 9, 1979, and Saturn on August 25, 1981. Voyager 1's trajectory, designed to send the spacecraft closely past the large moon Titan and behind Saturn's rings, bent the spacecraft's path inexorably northward out of the ecliptic plane -- the plane in which most of the planets orbit the Sun. Voyager 2 was aimed to fly by Saturn at a point that would automatically send the spacecraft in the direction of Uranus. After Voyager 2's successful Saturn encounter, it was shown that Voyager 2 would likely be able to fly on to Uranus with all instruments operat

Which planet has one moon called Charon?

How many moons does each planet have?  name of the moons | eNotes How many moons does each planet have?  name of the moons linda-allen | High School Teacher | (Level 3) Senior Educator Posted on January 10, 2010 at 10:19 PM Seems like this would be an easy question for you to find the answer yourself. In fact, if you had typed your question into the search box on the eNotes home page, you would have been directed to a page on eNotes titled "Space--How Many Moons Does Each Planet Have"? I have typed some of that info for you here. If you want to know the names we have given to each of the many moons, then click on the link in the Sources section and check out that page. Mercury--0 moons triteamdan | Teacher | (Level 2) Adjunct Educator Posted on February 18, 2012 at 9:18 AM No one knows.  New moons are discovered around the outer planets with fair regularity, the most recent of which was a fourth moon of Pluto's  Please note that there have also been new planets discovered recently (reclassified as dwarf planets) some of which also have moons. like 3 dislike 1 krishna-agrawala | College Teacher | (Level 3) Valedictorian Posted on Moons, also called satellites, are heavenly bodies that circle planets. IN our solar system seven of the planets have moon circling them. The names of these planets with number of moon that each of them have are listed below. Earth    ...   1.  This is called Moon Pluto     ...   1. This satellite is named Charon. Mars      ...   2. These are named Phobos and Deimos. Neptune ...   8. Only two of these can be seen by telescope on earth. These are named Titon and Nereid. Uranus   ...  15. Largest five of these are named Titania, Ariel, Miranda, Puck and Portia Jupiter   ...  16. Four of the largest of these are called Io, Europa, Ganymede ,and Callisto. Saturn   ...  18. Largest five of these are named Titan, Iapetus, Rhea, Dione and Tithys. There are no known satellites or moons of Mercury and Venus. like 5 dislike 1

What are the clouds of interstellar dust, said to be the birthplace of stars?

What is the interstellar medium? Links What is the Interstellar Medium? Simply put, the interstellar medium is the material which fills the space between the stars. Many people imagine outer space to be a complete vacuum, devoid of any material. Although the interstellar regions are more devoid of matter than any vacuum artificially created on earth, there is matter in space. These regions have very low densities and consist mainly of gas (99%) and dust . In total, approximately 15% of the visible matter in the Milky Way is composed of interstellar gas and dust. Interstellar Gas: Approximately 99% of the interstellar medium is composed of interstellar gas, and of its mass, about 75% is in the form of hydrogen (either molecular or atomic), with the remaining 25% as helium. The interstellar gas consists partly of neutral atoms and molecules , as well as charged particles, such as ions and electrons . This gas is extremely dilute, with an average density of about 1 atom per cubic centimeter. (For comparison, the air we breathe has a density of approximately 30,000,000,000,000,000,000 molecules per cubic centimeter.) Even though the interstellar gas is very dilute, the amount of matter adds up over the vast distances between the stars. The interstellar gas is typically found in two forms: Cold clouds of neutral atomic or molecular hydrogen; and Hot ionized hydrogen near hot young stars. The cold clouds of neutral or molecular hydrogen are the birthplace of new stars if they become gravitationally unstable and collapse. The neutral and molecular forms emit radiation in the radio band of the electromagnetic spectrum . The ionized hydrogen is produced when large amounts of ultraviolet radiation are released by hot newly-formed stars. This radiation ionizes the surrounding clouds of gas. Visible light is emitted when electrons recombine with the ionized hydrogen, which is seen as beautiful red colors of emission nebulae. Examples of emission nebulae are the Trifid Nebula or the Orion Nebula (seen in this photograph). Interstellar Dust: Interstellar dust is not like the dust that you might find under your bed; it is made of very different substances. These dust particles are extremely small, just a fraction of a micron across, which happens to be approximately the wavelength of blue light waves. The particles are irregularly shaped, and are composed of silicates, carbon, ice, and/or iron compounds. When light from other stars passes through the dust, a few things can happen. If the dust is thick enough, the light will be completely blocked, leading to dark areas. These dark clouds are known as dark nebulae. The Horsehead Nebula, seen to the left, is an example of this. Light passing through a dust cloud may not be completely blocked, although all wavelengths of light passing through will be dimmed somewhat. This phenomenon is known as extinction . The extinction is caused by the light being scattered off of the dust particles out of our line of sight, preventing the light from reaching us. The amount that the light is dimmed depends upon a few factors, including the thickness a nd density of the dust cloud, as well as the wavelength (color) of the light. Because of the size of the dust particles, scattering of blue light is favored. Therefore, less of the blue light reaches us, which means that the light that reaches us is more red than it would have been without the interstellar dust. This effect is known as interstellar reddening . (Note that this is not the same thing as redshift , which is due to the effects of relative movement between a light source and its receiver.) This process is similar to those that make the sun red at sunset. (To see an explanation of extinction and interstellar reddening that is more mathematical, please visit this site .) In turn, a dust cloud that is illuminated by star light, when viewed from the side, appears blue, as in the close-up of the "Egg Nebula" seen at right. This is similar to the blue sky we see, which is produced by sunlight scattered by the Earth's atmosphere. Aside from passing th

What is the astronomical unit equal to 32,616 light years?

Astronomical Unit Conversion - Measurement conversion A-I Measurement conversion A-I Most often used measurement conversion parsecs to kilometers (pc to km) converter 1 parsec is equal 30856776029497 kilometers (km) kilometers to parsecs (km to pc) converter 1 kilometer (km) is equal 3.2407792669074E-14 parsec kilometers to miles (km to mi) converter 1 kilometer (km) is equal 0.62118591342441 mile (mi) miles to kilometers (mi to km) converter 1 mile (mi) is equal 1.6098240130516 kilometers (km) miles to light-years (traditional) converter 1 mile (mi) is equal 1.7027507939076E-13 light-year (traditional) light-years (traditional) to miles converter 1 light-year (traditional) is equal 5872850000000 miles (mi) use this converter Definition Astronomical unit - a unit of length that is roughly equal to 150 million kilometers, the average distance from the Earth to the Sun. Other units of length used in astronomy are based on the speed of light and the time it takes light to cover a specific distance. Units of measurement parsec, astronomical unit (AU), kilometer (km), meter (m), mile (mi), light-year (Julian), light-year (Gregorian), light-year (traditional), light-year (tropical / solar), light-week, light-day, light-hour, light-minut, light-second About Astronomical Unit Conversion tool. We use rounding at unit-conversion.info. This means that some results will be rounded to avoid the numbers getting too long. While often rounding works up to a specific decimal place, we’ve decided that limiting the length of the result to 13 digits would be more favorable to keep the results consistent. The converters accept scientific notation and converts immediately.

Which is the second largest planet in the solar system?

What is the Second Biggest Planet in the Solar System? - Universe Today   Universe Today What is the Second Biggest Planet in the Solar System? Article Updated: 24 Dec , 2015 by Fraser Cain The biggest planet in the Solar System is Jupiter. But the title for the second biggest planet in our Solar System goes to Saturn. Just for a comparison, Jupiter measures 142,984 km across its equator. Saturn for comparison is only 120,536. So Jupiter is only 1.18 times as big of Saturn. Saturn is big, but it has a much lower mass. Once again, Jupiter is 3.34 times as massive as Saturn. Since Saturn is so big, but has so little mass, it has a very low density. In fact, if you had a pool big enough, Saturn would float. The density of Saturn is less than water. And this means that you wouldn’t experience a lot of gravity if you tried to walk on the “surface of Saturn”. If you were standing on the surface of Saturn (I know, that’s impossible), you would experience only 91% the force of Earth’s gravity. If you wanted to compare Saturn to Earth, it’s 9.4 times as big as the Earth, and 95 times as massive. It it was just a hollow shell, you could pack 763 Earths inside Saturn, with a little room to spare. Wanna see Jupiter? Here are amazing telescopes from Amazon.com which you can buy at reasonable prices: Here’s the article about how Jupiter is the biggest planet . And here’s another article about just how big planets can get . If you’d like more info on Saturn, check out Hubblesite’s News Releases about Saturn , and another page on Saturn from NASA’s Solar System Exploration Guide . We have recorded a whole series of podcasts about the Solar System at Astronomy Cast . Check them out here.

Which planet has been the focus of investigations for signs of life?

Life on Other Planets - Universe Today   Universe Today by Abby Cessna [/caption] For centuries, men have pondered the possibility of life on other planets and tried to prove its existence. Even before the first shuttle or probe was launched, stories of life on other planets and life invading our own planet, were published prolifically. Whether it’s a desire to connect with others or a burning curiosity to know whether we are truly alone, the question of life on other planets fascinates people from every walk of life. An article on extraterrestrial life would not be complete without discussing Mars. Mars has been the biggest focus of the ongoing search for life on other planets for decades. This is not just a wild assumption or fancy; there are several reasons why scientists consider Mars the best place to look for extraterrestrial life. One reason why many people, including scientists, look to Mars as a possible source of life is because they believe there may be water on the planet. Since the telescope was first invented, astronomers have been able to see the channels in the terrain that look like canals or canyons. Finding water on a planet is vitally important to proving that life exists there because it acts as a solvent in chemical reactions for carbon-based life. Another reason astronomers consider Mars as a likely location for life is because there is a good possibility that Mars is in the habitable zone. The habitable zone is a theoretical band of space a certain distance from the Sun in which conditions are optimal for the existence of carbon-based life. Unsurprisingly, Earth is in the middle of the habitable zone. Although astronomers do not know how far this zone could extend, some think that Mars could be in it. Most astronomers are looking for life that is carbon-based and similar to life on Earth. For instance, the habitable zone only applies to favorable conditions for supporting carbon-based life, and it is definitely possible for forms of life that do not need water to exist. Astronomers do not limit themselves to our Solar System either, suggesting that we should look at different solar systems. Scientists are planning to use interferometry–an investigative technique that implements lasers, which is used in astronomy as well as other fields– to find planets in the habitable zones of other solar systems. Astronomers believe that there are hundreds of solar systems and thousands of planets, which means that statistically the odds are favorable for finding another planet that supports life. While NASA develops better probes, the search for life continues. There are a number of sites with more information including life on other planets from Groninger Kapteyn Institute astronomy students and NASA predicts non-green plants on other planets from NASA.

In the general theory of relativity what causes space-time to be modified?

BBC Universe - General relativity: Warped space-time and black holes Listen now 45 min Melvyn Bragg and guests discuss the Vacuum of Space. Melvyn Bragg and guests discuss the Vacuum of Space, from the innards of the atom to the outer reaches of space. About General relativity General relativity (GR, also known as the general theory of relativity or GTR) is the geometric theory of gravitation published by Albert Einstein in 1915 and the current description of gravitation in modern physics. General relativity generalizes special relativity and Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time, or spacetime. In particular, the curvature of spacetime is directly related to the energy and momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of partial differential equations. Some predictions of general relativity differ significantly from those of classical physics, especially concerning the passage of time, the geometry of space, the motion of bodies in free fall, and the propagation of light. Examples of such differences include gravitational time dilation, gravitational lensing, the gravitational redshift of light, and the gravitational time delay. The predictions of general relativity have been confirmed in all observations and experiments to date. Although general relativity is not the only relativistic theory of gravity, it is the simplest theory that is consistent with experimental data. However, unanswered questions remain, the most fundamental being how general relativity can be reconciled with the laws of quantum physics to produce a complete and self-consistent theory of quantum gravity. Einstein's theory has important astrophysical implications. For example, it implies the existence of black holes—regions of space in which space and time are distorted in such a way that nothing, not even light, can escape—as an end-state for massive stars. There is ample evidence that the intense radiation emitted by certain kinds of astronomical objects is due to black holes; for example, microquasars and active galactic nuclei result from the presence of stellar black holes and supermassive black holes, respectively. The bending of light by gravity can lead to the phenomenon of gravitational lensing, in which multiple images of the same distant astronomical object are visible in the sky. General relativity also predicts the existence of gravitational waves, which have since been observed directly by physics collaboration LIGO. In addition, general relativity is the basis of current cosmological models of a consistently expanding universe.

Which space probes failed to find life on Mars?

Historic Spacecraft - Mars Probes Historic Spacecraft Historical Overview of Mars Exploration Since the early 1960's, dozens of spacecraft have been sent to explore Mars. The first spacecraft to successfully flyby Mars was the American Mariner 4 spacecraft. Orbit was first achieved with Mariner 9 in 1971. The mission returned thousands of images, giving us our first global look at the planet. The Soviet Mars 3 mission was the first to land on the surface. Unfortunately, communication ceased shortly after touchdown. The Viking program consisted of two orbiters and two landers. The landers studied many aspects of the surface and conducted sophisticated experiments to search for life. Mars missions have seen frequent failures, but have also some spectacular successes. 1996 saw the launch of Mars Pathfinder and Mars Global Surveyor . The Pathfinder lander tested an airbag landing technique and included the small Sojourner rover. Mars 96 , a Russian probe launched the same year, suffered a booster malfunction and fell back to Earth. The success of both Mars Pathfinder and Mars Global Surveyor were to start off a period of frequent missions. NASA planed on launching Mars spacecraft every two years as the planets aligned properly. Disaster struck in 1998. Both the Mars Climate Orbiter and the Mars Polar Lander spacecraft were destroyed upon reaching Mars. The success rate increased in the coming years. Mars Odyssey , an orbiter launched in 2001, was successful. During the 2003 launch window, NASA sent the twin Mars Exploration Rovers to the red planet. The rovers, known as Opportunity and Spirit, utilized an airbag landing technique similar to that tested on the Mars Pathfinder mission. The rovers both operated for years beyond their 90 day design life. Also launched in 2003 was the European Mars Express mission. A small lander, Beagle 2, was carried to Mars on the Mars Express spacecraft. The lander failed to contact Earth and might have crashed into the surface. Mars Reconnaissance Orbiter , launched in 2005, has provided high resolution imagery of the Martian surface. The spacecraft's cameras have even captured photos of landers on the surface. The Phoenix Mars Lander , launched in 2007, landed in the polar regions. Equipped with a robot arm, the probe was able to dig into a layer of water ice just centimeters below the surface. Landing in 2012, the large Mars Science Laboratory (MSL) rover carried a more sophisticated array of scientific instruments than recent landers. With power supplied by a radioisotope thermal generator, rather than by solar panels, MSL will be able to travel farther and faster then previous rovers. Still more missions are in the planning stages, including sophisticated rovers and sample return missions. Cronological List of Selected Mars Missions Mission Failed to enter Mars orbit. Mars 5 Entered Mars orbit, but failed after a few days Mars 6 Returned atmospheric data during descent, but did not survive landing. Mars 7 Mariner 4 Mission Mariner 3 & 4 were intended to conduct flybys of the planet Mars. Each spacecraft was launched on an Atlas-Agena D rocket (right). Mariner 3 Mariner 3 was launched on 5 November 1964. A launch shroud failed to separate and the spacecraft was not placed on the correct trajectory. Mariner 4 Mariner 4 was launched on 28 November 1964. The spacecraft successfully flew by Mars on 14 July 1965. The mission returned the first close-up images of another planets surface. Mariner 6 & 7 Mariner 6 Mission Mariner 6 & 7 were intended to conduct flybys of the planet Mars. Each spacecraft was launched on an Atlas-Centaur rocket (right). Mariner 6 Mariner 6 (Mariner F), was launched on 24 February 1969. The spacecraft successfully flew by Mars in July 1969. The mission returned images of the Martian surface. Mariner 7 Mariner 7 (Mariner G) was launched on 27 March 1969. The spacecraft successfully flew by Mars in August 1969. The mission returned images of the Martian surface. Mariner 8 & 9 Mariner 9 Mission Mariner 8 & 9, sometimes known as "Mariner Mars 71

Which type of celestial object emits bursts of energy at regular intervals?

Astronomical Terms Health and Science > Astronomy > Astronomical Measurement Astronomical Terms The Milky Way, the galaxy containing our solar system, is about 100,000 light-years in diameter and about 10,000 light-years thick. Aphelion: see Orbit. Apogee: see Orbit. Black hole: the theoretical end-product of the total gravitational collapse of a massive star or group of stars. Crushed even smaller than the incredibly dense neutron star, the black hole may become so dense that not even light can escape its gravitational field. In 1996, astronomers found strong evidence for a massive black hole at the center of the Milky Way. Recent evidence suggests that black holes are so common that they probably exist at the core of nearly all galaxies. Conjunction: the alignment of two celestial objects at the same celestial longitude. Conjunction of the Moon and planets is often determined with reference to the Sun. For example, Saturn is said to be in conjunction with the Sun when Saturn and Earth are aligned on opposite sides of the Sun. Mercury and Venus, the two planets with orbits within Earth's orbit, have two positions of conjunction. Mercury, for example, is said to be in inferior conjunction when the Sun and Earth are aligned on opposite sides of Mercury. Mercury is in superior conjunction when Mercury and Earth are aligned on opposite sides of the Sun. Dwarf planet: see Planet. Elongation: the angular distance between two points in the sky as measured from a third point. The elongation of Mercury, for example, is the angular distance between Mercury and the Sun as measured from Earth. Planets whose orbits are outside Earth's can have elongations between 0° and 180°. (When a planet's elongation is 0°, it is at conjunction; when it is 180°, it is at opposition.) Because Mercury and Venus are within Earth's orbit, their greatest elongations measured from Earth are 28° and 47°, respectively. Galaxy: gas and millions of stars held together by gravity. All that you can see in the sky (with a very few exceptions) belongs to our galaxy—a system of roughly 200 billion stars. The exceptions you can see are other galaxies. Our own galaxy, the rim of which we see as the “ Milky Way ,” is about 100,000 light-years in diameter and about 10,000 light-years in thickness. Its shape is roughly that of a thick lens; more precisely, it is a spiral nebula, a term first used for other galaxies when they were discovered and before it was realized that these were separate and distinct galaxies. Astronomers have estimated that the universe could contain 40 to 50 billion galaxies. In 2004, the Hubble Space Telescope and observers at the Keck Observatory in Hawaii discovered a new galaxy 13 billion light-years from Earth. Neutron star: an extremely dense star with a powerful gravitational pull. Some neutron stars pulse radio waves into space as they spin; these are known as pulsars . Occultation: the eclipse of one celestial object by another. For example, a star is occulted when the Moon passes between it and Earth. Opposition: the alignment of two celestial objects when their longitude differs by 180°. Opposition of the Moon and planets is often determined with reference to the Sun. For example, Saturn is said to be at opposition when Saturn and the Sun are aligned on opposite sides of Earth. Only the planets whose orbits lie outside Earth's can be in opposition to the Sun. Orbit: the path traveled by an object in space. The term comes from the Latin orbis, which means “circle” or “disk,” and orbita, “orbit.” Theoretically, there are four mathematical figures, or models, of possible orbits: two are open (hyperbola and parabola) and two are closed (ellipse and circle), but in reality all closed orbits are ellipses. Ellipses can be nearly circular, as are the orbits of most planets, or very elongated, as are the orbits of most comets, but the orbit revolves around a fixed, or focal, point. In our solar system, the Sun's gravitational pull keeps the planets in their elliptical orbits; the planets hold their moons in place similarly. For

Which country has the airline KLM?

Klm Airlines (KL) : Find Klm Airlines Flights and Deals – CheapOair Classes of Service World Business Class, Europe Business Class and Economy Class are the three classes of service offered by KLM Airlines. World Business Class: Pamper yourself with irresistible luxury in the World Business Class. Relax in bed-like seats that come with features like 180 degree recline, ample legroom and headrest. Enjoy a range of audio and video programs on your personal 17 in monitor, you can even request magazines on-board. Treat your taste buds to delicious three course meals prepared by quality Dutch chefs and don't forget to enjoy the exotic wines available on-board. Europe Business Class: In the Europe Business Class all the middle seats are unoccupied so privacy is guaranteed. Seats are extremely comfortable and come with features like superior reclining and ample legroom. Whether you want to treat your taste buds to delicious breakfasts, three course menus or exotic wines, the dining choices offered are impressive to say the least. Those of you who love a good read can enjoy the selection of newspapers and magazines available on-board. Economy Class: Seats are ergonomically designed and come equipped with features like ample legroom, headrest and superior reclining. Treat your taste buds to everything from delicious meals to alcoholic beverages, you can even request special meals (low salt, diabetic etc) in advance. On intercontinental flights passengers can enjoy a range of audio and video programs, while on flights within Europe passengers can choose from a selection of newspapers and magazines. Book KLM Airlines Tickets with CheapOair   KLM Airlines is the national airline of Netherlands, with its main operating hub situated at the Amsterdam Airport Schiphol, Netherlands. This airline is renowned for its network, and operates scheduled flights to more than 133 destinations across 69 countries. Some of the famous destinations that this airline covers are London, Orlando, Washington, Melbourne, Calgary, Vancouver, Beijing, Paris, Frankfurt, Mumbai, Tel Aviv and many more. KLM Airlines is one of the few airlines that rank high on all the fronts: comfort, dining and entertainment. In-Flight Amenities Enjoy more than 1000 hours of entertainment which includes about 80 movies, numerous television programs, music albums and much more. Begin your meal with a delicious appetizer, then enjoy the main dish and end the experience with an exotic dessert, your taste buds will certainly have a great time. Seats are designed for your comfort and come with features like 180 degree recline, ample legroom, headrest, footrest and much more. Online Check-In All you need is an internet connection and you can select your desired seat from the comfort of your home or office. After selecting your seat, print your boarding pass and you are good to go. This process is not only fast but also efficient. Web check-in is available from 30 hours up to an hour before the flight's scheduled departure time. Rewards Programs and Perks Enjoy special benefits and rewards with 'Flying Blue' which is KLM's frequent flyer program. Here's how it works, every time you fly with KLM or any of its code share partners, you earn a specific number of miles depending on your purchase. You can then redeem these miles for rewards like complimentary tickets, hotel stays, car rental offers and much more. Get there on time, every time! Check your flight status here.   Perfect services. Good food and drink. - Radoslav  Jan 18, 2017 V.C

What two letters are worth the most in a game of Scrabble?

10 Words That Will Win You Any Game of Scrabble | Mental Floss 10 Words That Will Win You Any Game of Scrabble Hasbro Like us on Facebook Whether you consider winning at Scrabble a case of extreme luck or supreme spelling ability, here are 10 words that—if conditions are right—will help you trump any opponent. 1. Oxyphenbutazone Definition: An anti-inflammatory medication used to treat arthritis and bursitis. Conditions: The theoretically highest-possible scoring word under American Scrabble play—as calculated by Dan Stock of Ohio—has never actually been played … and probably never will (unless you’re really, really lucky). That’s because it has to be played across three triple word score squares and build on eight already-played (and perfectly positioned) tiles. Points: 1,778 2. Quizzify Definition: To quiz or question. Conditions: Not only will you need to draw the game’s only Q and Z tiles (there’s only one of each), but a blank tile, too (in place of the second Z). Play this verb as your first word across two triple word squares with the Z on a double letter score square and you’ve got the game’s most valuable eight-letter bingo. Points: 419 3. Oxazepam Definition: An anti-anxiety drug. Conditions: All that stress will melt away if you can build on one existing letter , play across two triple word score squares, place one of the most valuable tiles (i.e. X or Z) on a double letter score square and net a 50-point bingo. Points: 392 4. Quetzals Definition: The national bird of Guatemala as well as one of its monetary units. Conditions: Placement is everything to score this whopper of a word: Building on one letter, use all seven letters on your rack for a 50-point bingo, with Q and S on triple word score square and Z on a double letter score space. Points: 374 5. Quixotry Definition: A romantic or quixotic idea or action. Conditions: In 2007, Michael Cresta used an already-played R and all seven of his tiles across two triple word score squares to earn the most points ever on a single turn, which aided in a second record for the full-time carpenter: the highest-ever individual game score (830 points). Points: 365 6. Gherkins Definition: A small pickle, made from an immature cucumber. Conditions: In 1985, Robert Kahn paid tribute to the pickle at the National Scrabble Championship in Boston—using an E and R already on the board—to set a record for a non-bingo word score. Points: 180 7. Quartzy Definition: Resembling quartz. Conditions: “Quartzy” held the record for highest-ever single turn score until “Quixotry” nearly doubled its total in 2007. Play it across a triple word score square with Z as a double letter score, with a 50-point bingo for using all seven letters on your rack. Points: 164 8. Muzjiks Definition: A Russian peasant. Conditions: On its own (with no bonuses or extra points), “muzjiks” is worth an impressive 29 points. But exhaust all of your tiles on your first turn to spell it, and you’ll earn more than four times that—which is what player Jesse Inman did at the National Scrabble Championship in Orlando in 2008 to earn the record for highest opening score. Points: 126 9. Syzygy Definition: An alignment of three celestial bodies. Conditions: Forget trying to pronounce it (though, for the record, it’s “SIZ-i-jee”). Instead, just remember how to spell it—and that it’s worth 21 points au naturel . You’ll need one blank tile to make up for the lack of Ys (there are only two in the game). For a higher total, land the Z on a double letter score square and the final Y on a triple word score square. Points: 93 10. Za Definition: Slang term for pizza. Conditions: Big words are great and all, but two-letter words can also score big . And be especially annoying to your opponent. Build on two As—one directly below, the other directly to the right of a triple letter square—to spell this two-letter delectable across and down. Points: 62

After how many years of marriage would you celebrate your ruby anniversary?

Wedding Anniversary List: Names by Years Married - Disabled World Wedding Anniversary List: Names by Years Married Print Published: 2011-06-27 (Rev. 2015-06-04) - Contact: Ian Langtree at Disabled World Synopsis: A list of wedding anniversaries by year that includes the names of materials symbols and flowers associated with the anniversary. About Wedding Anniversary A wedding anniversary is defined as the anniversary of the date a wedding took place. Traditional names exist for some of them: for instance, 50 years of marriage is called a "golden wedding anniversary" or simply a "golden anniversary" or "golden wedding". Main Document "In the United States, one can receive a greeting from the President for any wedding anniversary on or after the 50th." What is a Wedding Anniversary? A wedding anniversary is the anniversary of the date a wedding took place. On a wedding anniversary in many countries it is traditional to give a gift to your partner (or couples) that symbolize the number of years of marriage. The names of some wedding anniversaries provide guidance for appropriate or traditional gifts for the spouses to give each other; if there is a party to celebrate the wedding anniversary these gifts can be brought by the guests and/or influence the theme or decoration of the venue. Jump-To: Ring Size Chart Lists of wedding anniversary gifts vary by country. Listed below is a list of wedding anniversaries by year that includes materials, symbols, and flowers associated with the occasion. Wedding anniversary names common to most nations include: Wooden (5th), Tin (10th), Crystal (15th), China (20th), Silver (25th), Pearl (30th), Ruby (40th), Golden (50th), and Diamond (60th). Wedding Anniversary Gifts List 77.4 Facts: Wedding Anniversary The celebration of wedding anniversaries dates back to Roman times when husbands gave their wives a silver wreath for 25 years of marriage, and a gold wreath for 50. Today there are traditional and modern materials related to each wedding anniversary, usually progressing from the weakest to the strongest as the years go by, to symbolize the strengthening of the relationship. In the United States, one can receive a greeting from the President for any wedding anniversary on or after the 50th. In the British Commonwealth domains you may receive a message from the monarch for your 60th, 65th, and 70th wedding anniversaries, and any wedding anniversary after that by applying to Buckingham Palace in the U.K., or to the Governor-General's office in the other Commonwealth realms. An exception being Australia and Canada. The delivery of congratulatory messages marking 100th birthdays and 60th wedding anniversaries is arranged by the Anniversaries Office at Buckingham Palace. In Canada you may also receive a message from the Governor General for the 50th anniversary, and every 5th anniversary after that. In Australia may receive a letter of congratulations from the Governor General on the 50th and all subsequent wedding anniversaries; the Prime Minister, the federal Opposition leader, local members of parliament (both state and federal), and state Governors may also send salutations for the same anniversaries. Roman Catholics may apply for a Papal blessing through their local diocese for wedding anniversaries of a special nature such as their 25th, 50th, 60th, etc. anniversaries.

Where would a troglodyte live? In a cave, up a tree or underwater?

New Feature: Title Field in Questions - Etudes New Feature: Title Field in Questions June 11, 2015 by Etudes Admin 0 Instructors now have the ability to add a “Title” when authoring objective questions or essays (assignments) in the assessment engine of Etudes. This optional field provides a way to categorize questions by keywords or phrases. For example, the title may be the chapter or unit that the question’s content is derived from, or it could be used to identify questions in summative assessments to collect Student Learning Outcomes (SLO) data (see Using the Question Title Field for SLO Data Collection ).  Adding Titles to Questions When adding a question, you may also provide a title. Use one word or very short phrase for this field.  If titles are included in questions during authoring, they will be listed in a separate column in the question list of your pools.  The Title column is sortable. If you like to author your questions offline in a text file and bulk upload / paste them into Etudes via the offline authoring functionality, you can include titles to your questions by adding “QuestionTitle:” (case insensitive) after the question, as in the following: Where would a “troglodyte” live? *1. In a cave

How many counters does each player have at the start of a game of backgammon?

How Many Counters Does Each Player Have at the Start of a Game of Backgammon | uk.QACollections.com How Many Counters Does Each Player Have at the Start of a Game of Backgammon  How Many Counters Does Each Player Have at the Start of a Game of Backgammon? Each Player as 15 counters in a Backgammon. The counters are also known as checkers, draughts, stones, men or chips. Backgammon is one of the oldest board games, with archaeological evidence up to ... Read More » Related Videos Top Q&A For: How Many Counters Does Each Player Have at the ... How Many Counters in Backgammon? Backgammon has thirty pieces, or fifteen for each of the two players. The pieces in Backgammon are also known as checkers, draughts, pieces, men, stones or counters. How Many Senators Does Each State Have? Each state is represented by two senators. Each senator is given six years senate terms. According to the law, no person shall be a senator who have not attained the age of thirty. Where to Buy Backgammon Game Sets? Backgammon can be a fun and exciting game for the whole family to enjoy. When choosing a Backgammon set to buy, you will want to shop from a place that gives you a variety of options in style, desi... Read More » http://www.ehow.co.uk/how_4557155_where-buy-backgammon-game-sets.html How Many Calories Should a Man Have Each Day? A man's daily calorie intake is influenced by his age and activity levels, as well as his weight and other health factors. If you are trying to lose weight, you'll obviously need to intake fewer ca... Read More »

How many centimetres make up a hand, the measurement used on horses?

How to Measure the Height of Horses: 4 Steps (with Pictures) How to Measure the Height of Horses Community Q&A Egyptians created forms of measurement thousands of years ago. One of the measurements still widely used today is the hand. Each hand represents four inches and is the primary way to measure the height of a horse. By taking a linear measurement and converting the numbers to hands, the height of a horse can be determined. Steps 1 Purchase a horse measuring stick marked with hand measures. If a horse measuring stick is not available, a standard measuring tape is acceptable. Horse measuring sticks can be found at equestrian supply stores (tack shops), farm supply stores and from various online retailers. 2 Make sure the horse is standing on firm level ground with its front feet as even as possible. 3 Place the horse measuring stick or measuring tape at the base of one of the horse's front feet and pull the measuring device up to the withers. The withers is located at the top of the shoulders between the neck and back and is considered the highest point on a horse. The highest point of a horse is actually the top of its head, (also known as the poll), but since a horse moves its head up and down frequently, it is difficult to record this measurement accurately. Stretch the measuring device to the highest point of the withers. More precisely, extend the measuring device up to the spiny ridge between the horse's shoulder blades. 4 Record the measurement. If the horse measuring stick is being used, then the measurement can be recorded in hands immediately. If a measuring tape is being used, conversion of the measurement from inches to hands is required. One hand equals 4 inches (10.2 cm), so divide the measurement by 4. For example, if the horse measures 71 inches (180.3 cm), divide 71 by 4 inches. The result is 17 hands with 3 inches (7.6 cm) left over. The final height would be recorded as 17.75 hands. Community Q&A Can I increase the height of my horse? wikiHow Contributor Not really, though you can make sure to feed your horse the proper feed and nutrients when the horse is young, to prevent the horse from having stunted growth. When you're using a measuring stick, do you take the measurement from the top side or the bottom side of the reading bar? wikiHow Contributor Unanswered Questions Do you use the flat bottom of cross bar on stick or the curved top with level? If this question (or a similar one) is answered twice in this section, please click here to let us know. Video Tips The hand is the most common form of horse measurement in the United States, Canada, and England. However, throughout other locations around the world, the metric system is used to record the horse's height. When a horse measures one half hands, indicate the measurement with .2 and not with .5. A horse measuring stick is the easiest way to measure a horse quickly and accurately. A horse measuring under 14.3 hands high is, by definition, a pony, regardless of breed. The height of an average horse is roughly 16 hands.

In what year did the weather forecast appear in The Times newspaper for the first time?

History of the National Weather Service History of the National Weather Service Weather.gov > History of the National Weather Service The National Weather Service has its beginning in the early history of the United States. Weather always has been important to the citizenry of this country, and this was especially true during the 17th and 18th centuries. Weather also was important to many of the Founding Fathers. Colonial leaders who formed the path to independence of our country also were avid weather observers. Thomas Jefferson purchased a thermometer from a local Philadelphia merchant while in town for the adoption of the Declaration of Independence. He also purchased a barometer — one of the only ones in America at the time — a few days later from the same merchant. Incidentally, he noted that the high temperature in Philadelphia, Pa., on July 4, 1776 was 76 degrees. Jefferson made regular observations at Monticello from 1772-78, and participated in taking the first known simultaneous weather observations in America. George Washington also took regular observations; the last weather entry in his diary was made the day before he died. During the early and mid-1800's, weather observation networks began to grow and expand across the United States. Although most basic meteorological instruments had existed for over 100 years, it was the telegraph that was largely responsible for the advancement of operational meteorology during the 19th century. With the advent of the telegraph, weather observations from distant points could be "rapidly" collected, plotted and analyzed at one location. 1800-1899 2006-2009 2010-Current 1849: Smithsonian Institution supplies weather instruments to telegraph companies and establishes extensive observation network. Observations submitted by telegraph to the Smithsonian, where weather maps are created. By the end of 1849, 150 volunteers throughout the United States were reporting weather observations to the Smithsonian regularly. By 1860, 500 stations were furnishing daily telegraphic weather reports to the Washington Evening Star, and as the network grew, other existing systems were gradually absorbed, including several state weather services. 1860: 500 stations are making regular observations, but work is interrupted by the Civil War. 1869: Telegraph service, instituted in Cincinnati, began collecting weather data and producing weather charts. The ability to observe and display simultaneously observed weather data, through the use of the telegraph, quickly led to initial efforts toward the next logical advancement, the forecasting of weather. However, the ability to observe and forecast weather over much of the country, required considerable structure and organization, which could be provided through a government agency. 1870: A Joint Congressional Resolution requiring the Secretary of War "to provide for taking meteorological observations at the military stations in the interior of the continent, and at other points in the States and Territories...and for giving notice on the northern lakes and on the seacoast, by magnetic telegraph and marine signals, of the approach and force of storms" was introduced. Congress passed the resolution and on February 9, 1870, President Ulysses S. Grant signed it into law. A new national weather service had been born within the U.S. Army Signal Service’s Division of Telegrams and Reports for the Benefit of Commerce that would affect the daily lives of most of the citizens of the United States through its forecasts and warnings for years to come. 1870-1880: Gen. Albert J. Myer serves as chief signal officer, directing the new weather service. 1880: Upon the death of Gen. Myer, Gen. William Babcock Hazen takes over as chief signal officer. He serves until his death in 1887. 1887: Upon the death of Gen. Hazen, Maj. Gen. Adolphus Greely takes over as chief signal officer. He serves until his death in 1891. May 30, 1889: An earthen dam breaks near Johnstown, Pennsylvania. The flood kills 2,209 people and wrecks 1,880 homes and businesses. October 1, 1890: The we

What is the largest of the West Indian islands?

West Indies | Article about West Indies by The Free Dictionary West Indies | Article about West Indies by The Free Dictionary http://encyclopedia2.thefreedictionary.com/West+Indies Related to West Indies: East Indies West Indies, archipelago, between North and South America, curving c.2,500 mi (4,020 km) from Florida to the coast of Venezuela and separating the Caribbean Sea and the Gulf of Mexico from the Atlantic Ocean. The archipelago, sometimes called the Antilles, is divided into three groups: the Bahamas Bahamas, the , officially Commonwealth of the Bahamas, independent nation (2005 est. pop. 301,800), 4,403 sq mi (11,404 sq km), in the Atlantic Ocean, consisting of some 700 islands and islets and about 2,400 cays, beginning c.50 mi (80 km) off SE Florida and extending c. ..... Click the link for more information. ; the Greater Antilles ( Cuba Cuba , officially Republic of Cuba, republic (2005 est. pop. 11,347,000), 42,804 sq mi (110,860 sq km), consisting of the island of Cuba and numerous adjacent islands, in the Caribbean Sea. Havana is the capital and largest city. ..... Click the link for more information. , Jamaica Jamaica , independent state within the Commonwealth (2005 est. pop. 2,732,000), 4,232 sq mi (10,962 sq km), coextensive with the island of Jamaica, West Indies, S of Cuba and W of Haiti. Jamaica is the largest island in the Caribbean after Cuba and Hispaniola. ..... Click the link for more information. , Haiti Haiti , Fr. Haïti , officially Republic of Haiti, republic (2005 est. pop. 8,122,000), 10,700 sq mi (27,713 sq km), West Indies, on the western third of the island of Hispaniola. ..... Click the link for more information. , the Dominican Republic Dominican Republic , republic (2005 est. pop. 8,950,000), 18,700 sq mi (48,442 sq km), West Indies, on the eastern two thirds of the island of Hispaniola. The capital and largest city is Santo Domingo. ..... Click the link for more information. , and Puerto Rico Puerto Rico , island (2005 est. pop. 3,917,000), 3,508 sq mi (9,086 sq km), West Indies, c.1,000 mi (1,610 km) SE of Miami, Fla. Officially known as the Commonwealth of Puerto Rico (a self-governing entity in association with the United States), it includes the offshore islands ..... Click the link for more information. ); and the Lesser Antilles ( Leeward Islands Leeward Islands , northern group of the Lesser Antilles in the West Indies, extending SE from Puerto Rico to the Windward Islands. The principal islands are the American Virgin Islands; the French island and overseas dept. ..... Click the link for more information. , Windward Islands Windward Islands, southern group of the Lesser Antilles in the West Indies, curving generally southward for c.300 mi (480 km) from the Leeward Islands toward NE Venezuela. ..... Click the link for more information. , Trinidad and Tobago Trinidad and Tobago , officially Republic of Trinidad and Tobago, republic (2005 est. pop. 1,088,000), 1,980 sq mi (5,129 sq km), West Indies. The capital is Port of Spain. ..... Click the link for more information. , Barbados Barbados , island state (2005 est. pop. 279,300), 166 sq mi (430 sq km), in the West Indies. The capital and largest city is Bridgetown. Land, People, and Economy The island, E of St. Vincent, in the Windward Islands, is the easternmost of the Caribbean islands. ..... Click the link for more information. ) and the islands off the northern coast of Venezuela. The British dependent territories are the Cayman Islands Cayman Islands , British dependency (2005 est. pop. 44,300), 100 sq mi (259 sq km), comprising three low-lying islands in the West Indies. George Town, the capital and chief port, is on Grand Cayman; the other islands are Little Cayman and Cayman Brac. ..... Click the link for more information. , the Turks and Caicos Islands Turks and Caicos Islands , dependency of Great Britain (2005 est. pop. 20,600), 166 sq mi (430 sq km), West Indies. There are more than 30 cays and islands, of which eight are inhabited. Geographically, the islands are a southeastern continuation of the Bahamas. .....

St Johnstown was once the capital city of Scotland. By what name is St Johnstown now known?

 • Perth, Ontario - From Wikipedia, the free encyclopedia Perth, Scotland [44 miles (71km) N of Edinburgh, 22 miles (35km) SW of Dundee, 64 miles (103km) NE of Glasgow] The Perth Scotland City Hall at right [photo by Adam Murray - Perth Scotland] Known to the Romans as Bertha from the Celtic 'Aber The' meaning mouth of the Tay. The city has been a Royal Burgh since the 13thC and was a Royal residence throughout the middle ages. Perth is often referred to as the Ancient Capital of Scotland on this account until the mid-15th century. Perth, Scotland retains close ties to its counterpart in Ontario. Perth Ontario and Perth Scotland were "twinned" in 2000 . The Town of Perth Ontario invited a delegation from Perth Scotland to visit Canada to help celebrate the millennium in July of that year and at the same time form a twinning link. Like Perth Ontario, Perth Scotland has an old golf course, the oldest golf course in Scotland and indeed the world. The North Inch golf course was in use back in the 15th century. Church records show punishments being handed out to members who played golf on the Sabbath rather than go to church (circa 1596). It started life as a six hole course and was steadily increased throughout the years. Today of course it is a full 18 holes. It is not a difficult course, but very enjoyable to play. The course is best described as parkland. The North Inch is one of the two large parks in the city which have been there for hundreds of years. The other - the South Inch - also had a course, but this was closed some 200 years ago. [submitted by Jack Paterson - Totnes in Devon, Sout West England - a very lovely Elizabethan Town, the second oldest bourough in England] Perth & Kinross already had strong links with Perth, Ontario. Over the last few years the two communities, in particular the Pipe and Drum Bands had formed exchanges and maintained strong friendships. Adam Murray of Perth in Scotland recently discovered this site and provided the following photos from Perth Scotland.[Thanks Adam!] Adam Murray of Perth in Scotland recently discovered this site and provided the following photos from Perth Scotland.[Thanks Adam!] The church in the distance is called St Christophers and is of the protestant faith (Church of Scotland).   Tay Street from the Railroad Bridge King's Road on an Early Summer Morning looking down the Perth High Street towards the old high street at the end. looking down at Perth in the Tay valley from up on Moncrieffe Hill Dusk above Perth Scotland You may visit Perth, Scotland online at Perthshire Scotland or Perth and Kinross Council homepage. See Also: Perth, Western Australia [12 miles by rail from the sea at Freemantle, 1700 miles WNW of Melbourne] Perth, the capital city of Western Australia, is home to 1.38 million people and enjoys more hours of sunshine than any other capital city in Australia. Arguably the largest state in the world, Western Australia covers one-third of the Australian continent. Spanning over 2.5 million square kilometres (1 million square miles), Western Australia extends into different climatic zones simultaneously. When it is warm and dry in the north of the State, it is cool and wet in the south - that's how big Western Australia is. Named after the Scottish city, Perth was announced a city in 1856 by Queen Victoria. To read more on the history of Perth, see " Perth " See also: • Perth, Australia - From Wikipedia, the free encyclopedia Perth, Tasmania [Perth is a town in the north-east of Tasmania, Australia. It lies 20 km south of Launceston, on the Midlands Highway] Perth is on Tasmania, an island state of southeast Australia consisting of the island of Tasmania along with several smaller islands and separated from the mainland by Bass Strait. Abel Tasman explored the island in 1642, naming it Van Diemen's Land. It was renamed in his honor in 1853. Tasmania joined Australia in 1901. See also: North Perth, Ontario [172km W of Toronto, 102km N of London, 54km N of Stratford] The Town of North Perth , located in the northern reaches of Perth County Ontario, is a

What is the largest city in Switzerland?

Switzerland Facts on Largest Cities, Populations, Symbols - Worldatlas.com Ethnicity: German 65%, French 18%, Italian 10%, Romansch 1%, other 6% GDP total: $362.4 billion (2012 est.) GDP per capita: $54,600 (2012 est.) Language: German (official) 63.7%, French (official) 20.4%, Italian (official) 6.5%, Serbo-Croatian 1.5%, Albanian 1.3%, Portuguese 1.2%, Spanish 1.1%, English 1%, Romansch (official) 0.5%, other 2.8% note: German, French, Italian, and Romansch are all national and official languages Largest Cities: (by population) Zurich, Geneva, Basel, Bern, Lausanne Name: Switzerland's name comes from the German derivative Suito and the Schwyz canton in the central part of the country National Day: August 1 Religion: Roman Catholic 41.8%, Protestant 35.3%, Muslim 4.3%, Orthodox 1.8%, other Christian 0.4%, other 1%, unspecified 4.3%, none 11.1%

The Ural Mountains form a natural border between which two continents?

Europe Landforms and Land Statistics - Europe Landforms, Land Statistics Print this map Alps: Located in south-central Europe, they extend for almost 700 miles from the coastline of southern France (near Monaco) into Switzerland , northern Italy and Austria, then southeast through Slovenia, Croatia, Bosnia and Herzegovina as the (Dinaric Alps). Ending in Albania on the rugged coastline of the Adriatic Sea. Known for stunning scenery, glaciers, lakes and valleys and the best skiing conditions on the planet, they're the source of many rivers and tributaries including the Danube, Po, Rhine and Rhone . The highest point is Mont Blanc at 15,771 ft. (4,807 m) Apennines: The source of almost all rivers in Italy including the Arno, Tiber, and Volturno , the Apennines Mountains (Ital. Appennino) 830 miles (1,350 km) in length, form the backbone of the country, and run the entire length of the Italian Peninsula, ending on the island of Sicily. The highest point is Mt. Corno at 9,560 ft. (2,914 m). Atlantic Highlands: Formed million of years ago during the Caledonian mountain-building periods as western lands were (forced) or pushed against the Scandinavian Shield. Significant mountain ranges here include the Kjolen in Norway and Sweden, and the Pennines that stretch through the central United Kingdom. Balkan Mountains These mountains extend from Yugoslavia across Bulgaria. Additional ranges run through Albania, Greece and Macedonia. Its most famous mountain is Mt. Olympus, the highest and most awe-inspiring peak in all of Greece. In ancient times it was the mythical home of Zeus, and was declared the first national park in Greece in 1939. It stands at 9,568 ft. (2,918 m). Carpathian Mountains This mountain system located in eastern Europe is the source of the Dniester, Tisza and Vistula Rivers . They form the natural border between Slovakia and southern Poland, and then extend southward through Ukraine and into Romania. There are major subdivisions, and the highest point is Mt. Gerlachovkain in northern Slovakia, standing at 8,711 ft. (2,655 m). Caucasus Mountains Stretching from the Black Sea to the Caspian Sea, these volcanic mountains have many peaks above 15,000 ft. (4,572 m). The highest point (and the highest point in Europe) is located here; Mt. Elbrus at 18,506 ft. (5,642 m). Great Hungarian Plain Located in southeastern Europe, and surrounded by mountains, the land features several small forests and large patches of grassland. It averages only 100 meters above sea level and often suffers from dry conditions, thus relying on winter snow run-off from the Alps and Carpathian Mountains. Kjolen Mountains This jagged mountain system runs along the border of eastern Norway and western Sweden. The highest point is Mt. Kebnekaise, standing at 6,965 ft. (2,123 m). Massif Central This mountainous plateau of southeastern France is the source of the Allier, Creuse and Loire . It's about 32,189 sq. miles (85, 001 sq. km) in size, and the highest point is Puy de Sancy at 6,186 ft. (1,885 m). Mesata The central plateau, or Mesata, covers nearly half of the entire country of Spain. This high plateau averages about 2,300 ft. (700 m) in the north, and 2,000 ft. (600 m) in the south. It's surrounded by a series of mountain ranges including the Cantabrian, Sierra De Gata and Sierra Guadarrama in the north and central, and the Sierra Morena and Sierra Nevada in the south. These mountains separate the Meseta from the Costa Verde, the Ebro valley, the Mediterranean and the valleys of Andalucia. North European Plain The fertile North European Plain slopes to the north-northeast from the Alps, extending to the Baltic Sea, and on into Denmark and southern Finland, Norway and Sweden. It continues east for almost 2,500 miles (4000 km), on into the Russian Federation. The land is largely flat with smaller areas of hills, including the Central Russian Uplands. Farming is prevalent and agricultural communities dot the landscape. Pyrenees These mountains form the natural border between France and Spain and extend for about 270 miles from the Bay of Bisca