Alden (crater)
Alden is a lunar impact crater that lies on the far side of the Moon, between Hilbert David Hilbert (; ; 23 January 1862 – 14 February 1943) was a German mathematician and philosophy of mathematics, philosopher of mathematics and one of the most influential mathematicians of his time. Hilbert discovered and developed a broad ... to the north-northwest and Milne to the south-southeast. To the south-southwest lies Scaliger. Alden has a low rim that is overlain in the north and northeast by Alden C and the smaller Alden E. The rim is worn and eroded, especially along the southern wall. The floor is somewhat irregular and pitted. The small crater Alden V lies just inside the north rim, and is attached to Alden C to the east. Satellite craters By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Alden. References * * * * * * * * * * * * External links * {{DEFAULTSORT ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States's civil list of government space agencies, space program, aeronautics research and outer space, space research. National Aeronautics and Space Act, Established in 1958, it succeeded the National Advisory Committee for Aeronautics (NACA) to give the American space development effort a distinct civilian orientation, emphasizing peaceful applications in space science. It has since led most of America's space exploration programs, including Project Mercury, Project Gemini, the 1968–1972 Apollo program missions, the Skylab space station, and the Space Shuttle. Currently, NASA supports the International Space Station (ISS) along with the Commercial Crew Program and oversees the development of the Orion (spacecraft), Orion spacecraft and the Sp ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Harold Alden
Harold Lee Alden (January 10, 1890 – February 3, 1964) was an American astronomer. Early years and education Alden was born in Chicago, Illinois. He received his Bachelor of Arts from Wheaton College (Illinois) in 1912 and his master's from the University of Chicago in 1913. From 1912 to 1913 he was an assistant in the photographic photometry program at the Yerkes Observatory. He received his Ph.D. in 1917 from the University of Virginia. Professional life He worked for twenty years at the Yale Observatory in South Africa before returning to the University of Virginia. He is noted mainly for measuring stellar parallax, the proper motion of stars and long period variable stars. The crater Alden on the far side of the Moon is named in his honor. He returned to the University of Virginia in 1945 to become a Professor of Astronomy, chairman of the Astronomy Department and Director of the Leander McCormick Observatory. In 1951 he was the vice-president of the American Associat ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Alden Crater 3121 Med
Alden may refer to: Places United States * Alden, California, a former settlement * Alden, Illinois *Alden, Iowa Alden is a city in Hardin County, Iowa, Hardin County, Iowa, United States. The population was 763 at the 2020 United States Census, 2020 census. History Alden was laid out in 1855. It was named for its founder, Henry Alden, a native of Massach ... *Alden, Kansas *Alden, Michigan *Alden, Minnesota *Alden, Oklahoma *Alden, Pennsylvania *Alden, New York **Alden (village), New York *Alden, Wisconsin *Alden, Virginia *Alden Township, McHenry County, Illinois *Alden Township, Freeborn County, Minnesota *Alden Township, St. Louis County, Minnesota *Alden Township, Hettinger County, North Dakota *Alden Township, Hand County, South Dakota Elsewhere *Alden (crater), on the Moon *Alden, Norway, a small island in Sogn og Fjordane county *2941 Alden, an asteroid *Alden Valley, Lancashire, England Other uses *Alden (name) *Alden House (other), various houses on the Na ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Lunar Crater
Lunar craters are impact craters on Earth's Moon. The Moon's surface has many craters, all of which were formed by impacts. The International Astronomical Union currently recognizes 9,137 craters, of which 1,675 have been dated. History The word ''crater'' was adopted from the Greek word for "vessel" (, a Greek vessel used to mix wine and water). Galileo built his refracting telescope, first telescope in late 1609, and turned it to the Moon for the first time on November 30, 1609. He discovered that, contrary to general opinion at that time, the Moon was not a perfect sphere, but had both mountains and cup-like depressions. These were named craters by Johann Hieronymus Schröter (1791), extending its previous use with volcanoes. Robert Hooke in ''Micrographia'' (1665) proposed two hypotheses for lunar crater formation: one, that the craters were caused by projectile bombardment from space, the other, that they were the products of subterranean lunar volcanism. Scientific opin ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Impact Crater
An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Impact craters are typically circular, though they can be elliptical in shape or even irregular due to events such as landslides. Impact craters range in size from microscopic craters seen on lunar rocks returned by the Apollo Program to simple bowl-shaped depressions and vast, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth. Impact craters are the dominant geographic features on many solid Solar System objects including the Moon, Mercury (planet), Mercury, Callisto (moon), Callisto, Ganymede (moon), Ganymede, and most small moons and asteroids. On other planet ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Far Side (Moon)
The far side of the Moon is the hemisphere of the Moon that is facing away from Earth, the opposite hemisphere is the Near side of the Moon, near side. It always has the same surface oriented away from Earth because of synchronous rotation in the Moon's Orbit of the Moon, orbit. Compared to the near side, the far side's terrain is rugged, with a multitude of impact craters and relatively few flat and dark lunar mare, lunar maria ("seas"), giving it an appearance closer to other barren places in the Solar System such as Mercury (planet), Mercury and Callisto (moon), Callisto. It has one of the largest craters in the Solar System, the South Pole–Aitken basin. The hemisphere has sometimes been called the "Dark side of the Moon", where "dark" means "unknown" instead of "lacking sunlight" each location on the Moon experiences two weeks of sunlight while the opposite location experiences night. About 18 percent of the far side is occasionally visible from Earth due to oscillatio ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Moon
The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar day) that is synchronized to its orbital period (Lunar month#Synodic month, lunar month) of 29.5 Earth days. This is the product of Earth's gravitation having tidal forces, tidally pulled on the Moon until one part of it stopped rotating away from the near side of the Moon, near side, making always the same lunar surface face Earth. Conversley, the gravitational pull of the Moon, on Earth, is the main driver of Earth's tides. In geophysical definition of planet, geophysical terms, the Moon is a planetary-mass object or satellite planet. Its mass is 1.2% that of the Earth, and its diameter is , roughly one-quarter of Earth's (about as wide as the contiguous United States). Within the Solar System, it is the List of Solar System objects by ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Hilbert (crater)
Hilbert is a lunar impact crater that is located on the far side of the Moon, just past the southeast limb. It is named for German mathematician David Hilbert. It lies just beyond the region of the surface that is occasionally brought into view due to libration, and so this feature cannot be observed directly from the Earth. The crater is attached to the southeast rim of the walled plain Pasteur, a formation nearly half as large again as Hilbert. To the southeast of Hilbert is the smaller crater Alden, while Backlund lies to the west-northwest. Much of the outer rim of Hilbert remains relatively intact, although it is heavily eroded in places particularly in the south. The interior is relatively flat, but has been deeply gouged by several small craters. There is a short range of central ridges offset to the west of the interior midpoint. Just to the west of the ridges is Hilbert W, a crater with a smaller crater overlying the western rim, giving it a pear-like shape. Hilbert ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Milne (crater)
Milne is a large lunar crater that is located in the southern hemisphere on the Far side (Moon), far side of the Moon, named after the British mathematician and astrophysicist Arthur Milne, Edward Arthur Milne. It lies to the northeast of the Mare Australe, and southeast of Lacus Solitudinis. The formation has been heavily eroded and reshaped by a long history of impacts, leaving a low, irregular ridge line around most of the perimeter. The southern portion of the wall has been obliterated by impacts, and this area is now overlain by the craters Milne M and Milne N. Milne N has a ray system and is mapped as part of the Copernican period, Copernican System. Although the interior floor is relatively flat, it has been marred by many impacts in the surface. The most prominent of these is the satellite crater Milne K, which is located just to the south of the midpoint. Overlapping the southern rim of K is the smaller Milne L. In the northeast part of the floor is an unusual tight f ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Scaliger (crater)
Scaliger is a prominent lunar impact crater in the southern hemisphere on the far side of the Moon. It is attached to the northwest rim of the walled plain Milne, and the shared perimeter has reshaped the outer wall of Scaliger slightly, producing a straightened section along the southeast. To the west of Scaliger is the Lacus Solitudinis. The outer wall of Scaliger is somewhat polygonal in shape, especially in the southern half. The rim has not been heavily eroded by subsequent impacts, in contrast to the heavily worn Milne to the southeast. The inner wall of Scaliger's rim displays terrace Terrace may refer to: Landforms and construction * Fluvial terrace, a natural, flat surface that borders and lies above the floodplain of a stream or river * Terrace, a street suffix * Terrace, the portion of a lot between the public sidewalk a ...s, and a notable outer rampart overlaying the floor of Milne. The interior floor of Scaliger is relatively flat, with a rough surface near ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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United States Geological Survey
The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on March 3, 1879, to study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The agency also makes maps of planets and moons, based on data from U.S. space probes. The sole scientific agency of the U.S. Department of the Interior, USGS is a fact-finding research organization with no regulatory responsibility. It is headquartered in Reston, Virginia, with major offices near Lakewood, Colorado; at the Denver Federal Center; and in NASA Research Park in California. In 2009, it employed about 8,670 people. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on its hundredth anniversary, was "Earth Science in the Pub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Cambridge University Press
Cambridge University Press was the university press of the University of Cambridge. Granted a letters patent by King Henry VIII in 1534, it was the oldest university press in the world. Cambridge University Press merged with Cambridge Assessment to form Cambridge University Press and Assessment under Queen Elizabeth II's approval in August 2021. With a global sales presence, publishing hubs, and offices in more than 40 countries, it published over 50,000 titles by authors from over 100 countries. Its publications include more than 420 academic journals, monographs, reference works, school and university textbooks, and English language teaching and learning publications. It also published Bibles, runs a bookshop in Cambridge, sells through Amazon, and has a conference venues business in Cambridge at the Pitt Building and the Sir Geoffrey Cass Sports and Social Centre. It also served as the King's Printer. Cambridge University Press, as part of the University of Cambridge, was a ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |