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Polybius (crater)
Polybius is a lunar impact crater in the southeast part of the Moon, and is named after ancient Greek historian Polybius. It is located to the south-southeast of the larger crater Catharina, in the area framed by the Rupes Altai scarp. Some distance to the northeast is the Mare Nectaris, with the flooded craters Beaumont and Fracastorius. The crater rim of Polybius appears slightly distended in the northeast, and has a cut through the northern wall. But the wall is otherwise moderately intact with only minor erosion. The interior floor is flat and almost featureless, with no central rise. To the south and east, a ray from Tycho cuts across the bowl-shaped Polybius A and Polybius B craterlets. 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 Polybius. Polybius K is sometimes referred to as "Larrieu’s Dam" because the unusually straight northwest rim of the crater creat ... [...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] |
Beaumont (crater)
Beaumont is a lava-flooded crater located on the southwestern shore of the Mare Nectaris on Earth's Moon. It lies to the northwest of the similarly flooded crater remnant Fracastorius. To the west is the prominent crater Catharina. The crater is named after French geologist Léonce Élie de Beaumont. The rim of Beaumont is breached in the east, where the lava from Mare Nectaris broached the crater and flooded the interior. Now only a worn and crater-impacted outer wall remains. If the crater once possessed a central peak, it is no longer apparent. The floor contains several hills and small craters. A low ridge runs northward from the crater rim across the Mare Nectaris. 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 Beaumont. File:Beaumont D crater AS14-73-10045.jpg, Beaumont D from Apollo 14 Apollo 14 (January 31, 1971February 9, 1971) was the eighth crewed missi ... [...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] |
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] |
Tycho (crater)
Tycho () is a prominent lunar impact crater located in the southern lunar highlands, named after the Danish astronomer Tycho Brahe (1546–1601)., accessed 19 February 2019 It is estimated to be 108 million years old. To the south of Tycho is the crater Street, to the east is Pictet, and to the north-northeast is Sasserides. The surface around Tycho is replete with craters of various sizes, many overlapping still older craters. Some of the smaller craters are secondary craters formed from larger chunks of ejecta from Tycho. It is one of the Moon's brightest craters, with a diameter of and a depth of . Age and description Tycho is a relatively young crater, with an estimated age of 108 million years ( Ma), based on analysis of samples of the crater ray recovered during the Apollo 17 mission. This age initially suggested that the impactor may have been a member of the Baptistina family of asteroids, but as the composition of the impactor is unknown this remained conjecture. ... [...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] |
Fracastorius (crater)
Fracastorius is the lava-flooded remnant of an ancient lunar impact crater located at the southern edge of Mare Nectaris. To the northwest of this formation lies the crater Beaumont, while to the northeast is Rosse. The northern wall of this crater is missing, with only mounds appearing in the lunar mare to mark the outline. The lava that formed Mare Nectaris also invaded this crater, so the structure now forms a bay-like extension. The remainder of the rim is heavily worn and covered in lesser impact craters, leaving little of the original rim intact. The maximum elevation of the rim is 2.4 km. The most prominent of these craters is Fractastorius D, which overlies a portion of the western rim. Fracastorius has no central peak, but a long, slender rille Rille (German for 'groove') is typically used to describe any of the long, narrow depressions in the surface of the Moon that resemble channels. The Latin term is ''rima'', plural ''rimae''. Typically, a rille can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mare Nectaris
Mare Nectaris (Latin ''nectaris'', the "Sea of Nectar") is a small lunar mare or sea (a volcanic lava plain noticeably darker than the rest of the Moon's surface) located south of Mare Tranquillitatis southwest of Mare Fecunditatis, on the near side of the moon. Montes Pyrenaeus borders the mare to the east and Sinus Asperitatis fuses to its northwestern edge. It is 84,000 square kilometers in size. Several large craters are situated at the borders of Mare Nectaris. The biggest one is lava-filled Fracastorius (124 km), which fuses with southern coast of the Sea. A prominent trio of 100-km craters Theophilus, Cyrillus and Catharina is located near northwestern coast. Other notable feature is a "ghost crater" Daguerre, almost entirely covered with lava, in the northern part of Mare Nectaris. Mare Nectaris is located in the central part of 860-km-diameter impact basin, which was formed 3.8–3.9 billion years ago. This event marks the beginning of Nectarian period of the lu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polybius
Polybius (; grc-gre, Πολύβιος, ; ) was a Greek historian of the Hellenistic period. He is noted for his work , which covered the period of 264–146 BC and the Punic Wars in detail. Polybius is important for his analysis of the mixed constitution or the separation of powers in government, his in-depth discussion of checks and balances to limit power, and his introduction of "the people", which influenced Montesquieu's ''The Spirit of the Laws'', John Locke's ''Two Treatises of Government'', and the framers of the United States Constitution. The leading expert on Polybius for nearly a century was F. W. Walbank (1909–2008), who published studies related to him for 50 years, including a long commentary of his ''Histories'' and a biography. Early life Polybius was born around 200 BC in Megalopolis, Greece, Megalopolis, Arcadia (region), Arcadia, when it was an active member of the Achaean League. The town was revived, along with other Achaean states, a century before he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
