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Snellius (crater)
Snellius is a lunar impact crater located near the southeast limb of the Moon. The rim of Snellius is heavily worn and eroded, with overlapping craterlets. The floor is somewhat irregular and uneven. The western rim marks the start of the Vallis Snellius, one of the longest valleys on the Moon. It continues nearly 500 kilometers to the northwest to near the edge of Mare Nectaris. Its origin is most likely associated with the formation of the lunar mare. To the northeast is the large crater Petavius. South of Snellius is the crater Stevinus. Just to the northwest is Snellius A, a crater with a notable ray system that overlaps the southwest reaches of Mare Fecunditatis to the north. It is named after Dutch astronomer, mathematician and physicist, Willebrord Snellius Willebrord Snellius (born Willebrord Snel van Royen) (13 June 158030 October 1626) was a Dutch astronomer and mathematician, Snell. His name is usually associated with the law of refraction of light known as S ... [...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, Lunar Orbiter Program, designed to orbit the Moon, after the three previous orbiters had completed the required needs for Project Apollo, 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 Free-return trajectory, cislunar trajectory and injected into an elliptical near polar high lunar orbit for data acquisition. The orbit was with an inclination of 85.5 degrees and a period of 12 hours. After initial photography on May 11, 1967 problems started occu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ray System
A ray system comprises radial streaks of fine '' ejecta'' thrown out during the formation of an impact crater, looking somewhat like many thin spokes coming from the hub of a wheel. The rays may extend for lengths up to several times the diameter of their originating crater, and are often accompanied by small secondary craters formed by larger chunks of ejecta. Ray systems have been identified on the Moon, Earth ( Kamil Crater), Mercury, and some moons of the outer planets. Originally it was thought that they existed only on planets or moons lacking an atmosphere, but more recently they have been identified on Mars in infrared images taken from orbit by '' 2001 Mars Odyssey''s thermal imager. Rays appear at visible, and in some cases infrared wavelengths, when ejecta are made of material with different reflectivity (i.e., albedo) or thermal properties from the surface on which they are deposited. Typically, visible rays have a higher albedo than the surrounding surface. More rarel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterling Publishing Co
Sterling Publishing Company, Inc. is a publisher of a broad range of subject areas, with multiple imprints and more than 5,000 titles in print. Founded in 1949 by David A. Boehm, Sterling also publishes books for a number of brands, including AARP, Hasbro, Hearst Magazines, and ''USA TODAY'', as well as serves as the North American distributor for domestic and international publishers including: Anova, the Brooklyn Botanic Garden, Carlton Books, Duncan Baird, Guild of Master Craftsmen, the Orion Publishing Group, and Sixth & Spring Books. Sterling also owns and operates two verticals, Lark Crafts and Pixiq. Sterling Publishing is a wholly owned subsidiary of Barnes & Noble, which acquired it in 2003. On January 5, 2012, ''The Wall Street Journal'' reported that Barnes & Noble had put its Sterling Publishing business up for sale. Negotiations failed to produce a buyer, however, and Sterling is reportedly no longer for sale as of March, 2012. In January 2022, Sterling rebranded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jonathan's Space Report
''Jonathan's Space Report'' (JSR) is a newsletter about the Space Age, hosted at Jonathan's Space Page. It is written by Jonathan McDowell, a Center for Astrophysics Harvard & Smithsonian astrophysicist. It is updated as McDowell's schedule permits, but he tries to publish two issues each month. Originally the website was hosted on a Harvard University account, but was moved in late 2003 to a dedicated domain. Started in 1989, the newsletter reports on recent space launches, International Space Station activities and space craft developments. McDowell's report occasionally corrects NASA's official web sites, or provides additional data on classified launches that aren't available elsewhere. Associated projects on the JSR web site are: * A catalog of all known geosynchronous satellites and their current positions * A listing of satellite launch attempts * A cross-reference between catalog number and international designation of artificial satellites McDowell has long campaigne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambridge University Press
Cambridge University Press is the university press of the University of Cambridge. Granted letters patent by Henry VIII of England, King Henry VIII in 1534, it is the oldest university press A university press is an academic publishing house specializing in monographs and scholarly journals. Most are nonprofit organizations and an integral component of a large research university. They publish work that has been reviewed by schola ... in the world. It is also the King's Printer. Cambridge University Press is a department of the University of Cambridge and is both an academic and educational publisher. It became part of Cambridge University Press & Assessment, following a merger with Cambridge Assessment in 2021. With a global sales presence, publishing hubs, and offices in more than 40 Country, countries, it publishes over 50,000 titles by authors from over 100 countries. Its publishing includes more than 380 academic journals, monographs, reference works, school and uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Geological Survey
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization's work spans the disciplines of biology, geography, geology, and hydrology. The USGS is a fact-finding research organization with no regulatory responsibility. The agency was founded on March 3, 1879. The USGS is a bureau of the United States Department of the Interior; it is that department's sole scientific agency. The USGS employs approximately 8,670 people and is headquartered in Reston, Virginia. The USGS also has major offices near Lakewood, Colorado, at the Denver Federal Center, and Menlo Park, California. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on the occasion of its hundredt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew spacecraft, and the planned Lunar Gateway space station. The agency is also responsible for the Launch Services Program, which provides oversight of launch operations and countdown management f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willebrord Snellius
Willebrord Snellius (born Willebrord Snel van Royen) (13 June 158030 October 1626) was a Dutch astronomer and mathematician, Snell. His name is usually associated with the law of refraction of light known as Snell's law. The lunar crater Snellius is named after Willebrord Snellius. The Royal Netherlands Navy has named three survey ships after Snellius, including a currently-serving vessel. Biography Willebrord Snellius was born in Leiden, Netherlands. In 1613 he succeeded his father, Rudolph Snel van Royen (1546–1613) as professor of mathematics at the University of Leiden. Snellius' triangulation In 1615, Snellius, after the work of Eratosthenes in Ptolemaic Egypt in the 3rd century BC, probably was the first to try to do a large-scale experiment to measure the circumference of the earth using triangulation. He was helped in his measurements by two of his students, the Austrian barons Erasmus and Casparus Sterrenberg. In several cities he also received su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mare Fecunditatis
Mare Fecunditatis (Latin ''fēcunditātis'', the "Sea of Fecundity" or "Sea of Fertility") is a lunar mare in the eastern half of the visible Moon. The mare has a maximum diameter of 840 km. __NOTOC__ Description The Fecunditatis basin formed in the Pre-Nectarian epoch, while the basin material surrounding the mare is of the subsequent Nectarian epoch. The mare material is of the Upper Imbrian epoch and is relatively thin compared to the neighboring Mare Crisium or Mare Tranquillitatis. This basin is overlapped with the Nectaris, Tranquillitatis, and Crisium basins. Fecunditatis basin meets Nectaris basin along Fecunditatis' western edge, with the area along this zone faulted by arcuated grabens. On the eastern edge of Fecunditatis is the crater Langrenus. Near the center lie the interesting craters Messier and Messier A. It was here that the first automated sample return took place via the Luna 16 probe, in September 1970. Sinus Successus lies along the eastern edge of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stevinus (crater)
Stevinus is a lunar impact crater located in the southeast part of the Moon. To the southeast is the large crater Furnerius. Just to the northeast is Snellius and the Vallis Snellius crater valley. To the west-northwest lies Reichenbach. To the west-northwest of Stevinus is the tiny crater Stevinus A, a feature that possesses a small ray system and a displays a high albedo. Stevinus has a high inner wall and a central peak at the midpoint of the interior floor. The inner walls are slumped, so that the side slopes down sharply, then more gradually. There are several small ridges on the floor, in addition to the peak. Due to its ray system, Stevinus is mapped as part of the Copernican System.The geologic history of the Moon, 1987, Wilhelms, Don E.; with sections by McCauley, John F.; Trask, Newell J. USGS Professional Paper: 1348. Plate 11: Copernican Systemonline It is named for Simon Stevin Simon Stevin (; 1548–1620), sometimes called Stevinus, was a Flemish mathem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willebrord Snell
Willebrord Snellius (born Willebrord Snel van Royen) (13 June 158030 October 1626) was a Dutch astronomer and mathematician, Snell. His name is usually associated with the law of refraction of light known as Snell's law. The lunar crater Snellius is named after Willebrord Snellius. The Royal Netherlands Navy has named three survey ships after Snellius, including a currently-serving vessel. Biography Willebrord Snellius was born in Leiden, Netherlands. In 1613 he succeeded his father, Rudolph Snel van Royen (1546–1613) as professor of mathematics at the University of Leiden. Snellius' triangulation In 1615, Snellius, after the work of Eratosthenes in Ptolemaic Egypt in the 3rd century BC, probably was the first to try to do a large-scale experiment to measure the circumference of the earth using triangulation. He was helped in his measurements by two of his students, the Austrian barons Erasmus and Casparus Sterrenberg. In several cities he also received support ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petavius (crater)
Petavius is a large lunar impact crater located to the southeast of the Mare Fecunditatis, near the southeastern lunar limb. Attached to the northwest rim is the smaller crater Wrottesley. To the southeast are Palitzsch, Vallis Palitzsch, and Hase. Farther to the north is the large crater Vendelinus. Petavius appears oblong when viewed from the Earth due to foreshortening. Petavius is Imbrian in age. The outer wall of Petavius is unusually wide in proportion to the diameter, and displays a double rim along the south and west sides. The height of the rim varies by as much as 50% from the lowest point, and a number of ridges radiate outwards from the rim. The convex crater floor has been resurfaced by lava flow, and displays a rille system named the Rimae Petavius. The large central mountains are a prominent formation with multiple peaks, climbing 1.7 kilometers above the floor. A deep fracture runs from the peaks toward the southwest rim of the crater. Rev. T. W. Webb describe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
