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Fermat (crater)
Fermat is a lunar impact crater located to the west of the Rupes Altai escarpment. To the west-southwest is the larger crater Sacrobosco, and to the southwest is the irregular Pons. It is 39 kilometers in diameter and two kilometers deep.''Autostar Suite Astronomer Edition''. CD-ROM. Meade, April 2006. The rim of Fermat is worn and somewhat irregular, but still possesses an outer rampart. The north rim is indented by a double crater formation that includes Fermat A. The floor is relatively flat and does not have a central rise. The crater is from the Pre-Imbrian period, 4.55 to 3.85 billion years ago. It is named for 17th century French mathematician Pierre de Fermat Pierre de Fermat (; between 31 October and 6 December 1607 – 12 January 1665) was a French mathematician who is given credit for early developments that led to infinitesimal calculus, including his technique of adequality. In particular, he .... Satellite craters By convention these features are identifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Orbiter 4
Lunar Orbiter 4 was a robotic U.S. spacecraft, part of the Lunar Orbiter Program, designed to orbit the Moon, after the three previous orbiters had completed the required needs for Apollo mapping and site selection. It was given a more general objective, to "perform a broad systematic photographic survey of lunar surface features in order to increase the scientific knowledge of their nature, origin, and processes, and to serve as a basis for selecting sites for more detailed scientific study by subsequent orbital and landing missions". It was also equipped to collect selenodetic, radiation intensity, and micrometeoroid impact data. Mission Summary The spacecraft was placed in a cislunar trajectory and injected into an elliptical near polar high lunar orbit In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre De Fermat
Pierre de Fermat (; between 31 October and 6 December 1607 – 12 January 1665) was a French mathematician who is given credit for early developments that led to infinitesimal calculus, including his technique of adequality. In particular, he is recognized for his discovery of an original method of finding the greatest and the smallest ordinates of curved lines, which is analogous to that of differential calculus, then unknown, and his research into number theory. He made notable contributions to analytic geometry, probability, and optics. He is best known for his Fermat's principle for light propagation and his Fermat's Last Theorem in number theory, which he described in a note at the margin of a copy of Diophantus' ''Arithmetica''. He was also a lawyer at the '' Parlement'' of Toulouse, France. Biography Fermat was born in 1607 in Beaumont-de-Lomagne, France—the late 15th-century mansion where Fermat was born is now a museum. He was from Gascony, where his father, Do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Craters
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 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 opinion as to the ori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Crater
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity 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. Lunar impact craters range from microscopic craters on lunar rocks returned by the Apollo Program and small, simple, bowl-shaped depressions in the lunar regolith to large, 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, Callisto, Ganymede and most small moons and asteroids. On other planets and moons that experience more active surface geological processes, such as Earth, Venus, Europa, Io and Titan, visible impact craters are less common because they become ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rupes Altai
Rupes Altai is an escarpment in the lunar surface that is located in the southeastern quadrant of the Moon's near side. It is named for the Altai Mountains in Asia, and is the most prominent lunar escarpment. The selenographic coordinates of this feature are , and it has a length of about 427 km. The southeastern end of the cliff terminates along the western edge of the crater Piccolomini. It then arcs irregularly towards the north, climbing to heights of nearly a kilometer. The northern end of the arc is an irregular region with no clearly defined terminus, where it brackets the prominent craters Theophilus, Cyrillus, and Catharina. This cliff forms the southwestern rim of the Nectaris impact basin. This feature is difficult to locate during the full moon when the sunlight is nearly overhead. It appears as a bright, winding line about five days after the new moon, and casts a long, irregular shadow about four days after the full moon, when the sunset terminator is nearby ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escarpment
An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations. The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''escarpment''. Some sources differentiate the two terms, with ''escarpment'' referring to the margin between two landforms, and ''scarp'' referring to a cliff or a steep slope. In this usage an escarpment is a ridge which has a gentle slope on one side and a steep scarp on the other side. More loosely, the term ''scarp'' also describes a zone between a coastal lowland and a continental plateau which shows a marked, abrupt change in elevation caused by coastal erosion at the base of the plateau. Formation and description Scarps are generally formed by one of two processes: either by differential erosion of sedimentary rocks, or by movement of the Earth's crust at a geologic fault. The first process is the more common type: the escarpment is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacrobosco (crater)
Sacrobosco is an irregular lunar impact crater that is located in the rugged southern highlands to the west of the Rupes Altai escarpment. It is a readily identified feature due to the three circular craters that lie on its floor. The rim of Sacrobosco is heavily worn and eroded, especially in the northeast. The floor is relatively flat in the south, except where overlain by Sacrobosco A and B, but is somewhat irregular in the northeast. To the northwest of Sacrobosco is the double crater Abenezra and Azophi. To the east-northeast is Fermat, and to the south-southwest lies Pontanus. 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 Sacrobosco. References * * * * * * * * * * * * {{refend Impact craters on the Moon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pons (crater)
Pons is a lunar impact crater that is located to the west of the prominent Rupes Altai scarp. It was named after French astronomer Jean-Louis Pons. It lies to the southeast of the crater Sacrobosco, and southwest of Polybius. To the northwest along the same flank of the formation is the crater Fermat Pierre de Fermat (; between 31 October and 6 December 1607 – 12 January 1665) was a French mathematician who is given credit for early developments that led to infinitesimal calculus, including his technique of adequality. In particular, he i .... The rim of Pons is somewhat elongated in shape, being longer along a northeast–southwest axis than in the perpendicular direction. The outer wall is irregular and notched, particularly at the northeastern end where it is partly overlain by the satellite crater Pons D and multiple smaller formations. The interior is uneven, with low ridges projecting from the north and southeastern rims. Satellite craters By convention these feature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rampart
Rampart may refer to: * Rampart (fortification), a defensive wall or bank around a castle, fort or settlement Rampart may also refer to: * "O'er the Ramparts We Watched" is a key line from "The Star-Spangled Banner", the national anthem of the United States of America * LAPD Rampart Division, a division of the Los Angeles Police Department ** Rampart scandal, a blanket term for the widespread corruption of the Rampart Division * ''Ramparts'' (magazine), a leftist American magazine that was published from 1962 through 1975 * Rampart Search and Rescue, Adams County, Colorado * RampART Social Center, an anti-authoritarian social centre in Whitechapel, East London UK * Apache Rampart module, a module from the Apache Software Foundation for Web Services security * Rampart High School, a National School of Excellence in Colorado Springs, Colorado * Ramparts (Lille Gate) Commonwealth War Graves Commission Cemetery in the Ypres Salient, Belgium * Rampart (G.I. Joe), a fictional char ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kalmbach Books
Kalmbach Media (formerly Kalmbach Publishing Co.) is an American publisher of books and magazines, many of them railroad-related, located in Waukesha, Wisconsin. History The company's first publication was ''The Model Railroader'', which began publication in the summer of 1933 with a cover date of January 1934. A press release announcing the magazine appeared in August 1933, but did not receive much interest. In 1940, business was good enough for Kalmbach to launch another magazine about railroads in general with the simple title of '' Trains Magazine''. From its first issue dated November 1940, it grew quickly from an initial circulation of just over 5,000. Kalmbach became exclusively a publisher when it discontinued its printing operations in 1973, opting to contract production from other printers. In 1985, Kalmbach purchased AstroMedia Corporation, adding its four magazines: ''Astronomy'', ''Deep Sky'', the children's science magazine ''Odyssey'' and ''Telescope Making' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Geologic Timescale
The lunar geological timescale (or selenological timescale) divides the history of Earth's Moon into five generally recognized periods: the Copernican, Eratosthenian, Imbrian (Late and Early epochs), Nectarian, and Pre-Nectarian. The boundaries of this time scale are related to large impact events that have modified the lunar surface, changes in crater formation through time, and the size-frequency distribution of craters superposed on geological units. The absolute ages for these periods have been constrained by radiometric dating of samples obtained from the lunar surface. However, there is still much debate concerning the ages of certain key events, because correlating lunar regolith samples with geological units on the Moon is difficult, and most lunar radiometric ages have been highly affected by an intense history of bombardment. Lunar stratigraphy The primary geological processes that have modified the lunar surface are impact cratering and volcanism, and by using standard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
