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Main (lunar Crater)
Main is a lunar impact crater that is located near the north pole of the Moon. The southern rim of this formation has merged with the larger crater Challis to the south, and the level interior floor connects the two craters through a narrower gap. To the north-northwest of Main is Gioja. This formation consists of three overlapping craters that were joined together when the interior floor was resurfaced by lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or ... flows, leaving a generally circular formation with outward bulges to the west and northeast. The same lava has joined the floor of Main with Challis to the south. The surviving rim of Main is a low slope that is nearly level with the surrounding terrain at its top. There is a small crater lying across the eastern rim that ... [...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] |
Challis (crater)
240px, Location of the crater Challis Challis is a lunar impact crater that is located in the northern regions of the Moon's near side, close enough to the limb to appear significantly foreshortened when viewed from the Earth. It is joined to the crater Main through a break in the northern rim, and is close to Scoresby Scoresby may refer to: People * William Scoresby (1789–1857), British Arctic explorer, scientist and clergyman * William F. Scoresby (1840–1884), New York politician * William Scoresby Routledge (1859–1939), British ethnographer, anthropolo ... along the southeast side. The rim of this crater has been damaged and eroded by a history of impacts, with the most intact portion located along the southeastern half. A small crater lies across the southern rim, and the remaining rim is notched and irregular. The interior floor of both Challis and Main have been resurfaced forming a relatively level bottom common to both formations. This surface is marked only by mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Main
The Reverend Robert Main (12 July 1808 – 9 May 1878) was an English astronomer. Life Born at Upnor in Kent, he was the eldest son of Thomas Main; Thomas John Main the mathematician was a younger brother. Robert Main attended school in Portsea, Portsmouth before studying mathematics at Queens' College, Cambridge, where he graduated as sixth wrangler in 1834. He served for twenty-five years (1835–60) as First Assistant at the Royal Greenwich Observatory, and published numerous articles, particularly on stellar and planetary motion, stellar parallax, and the dimensions and shapes of the planets. From 1841 to 1861 he was successively an honorary secretary, a vice-president, and President of the Royal Astronomical Society, and in 1858 was awarded the Society's Gold Medal. In 1860 he became director of Radcliffe Observatory at Oxford University after the death of Manuel Johnson, and was elected as a Fellow of the Royal Society. An ordained priest of the Church of Engl ... [...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 origin ... [...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 eroded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of Australia). The Moon is a planetary-mass object with a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term and larger than all known dwarf planets of the Solar System. It lacks any significant atmosphere, hydrosphere, or magnetic field. Its surface gravity is about one-sixth of Earth's at , with Jupiter's moon Io being the only satellite in the Solar System known to have a higher surface gravity and density. The Moon orbits Earth at an average distance of , or about 30 times Earth's diameter. Its gravitational influence is the main driver of Earth's tides and very slowly lengthens Earth's day. The Moon's orbit around Earth has a sidereal period of 27.3 days. During each synodic period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gioja (crater)
Gioia is a lunar impact crater that is located in the vicinity of the north pole of the Moon. It is named after the Italian inventor Flavio Gioia. As it lies so close to the northern limb, it is viewed nearly from the edge making difficult to observe from the Earth. The crater is attached to the southern rim of the larger Byrd, a formation with low walls. To the south-southeast is the crater Main. The rim of Gioia remains nearly circular, but is worn and somewhat eroded. The exterior 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 ...s have been modified by subsequent impacts, particularly along the western rim. The rim achieves its high point to the northwest, where it has been reinforced by the rim of the crater Byrd and other since-vanished formations. The interior floor is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or underwater, usually at temperatures from . The volcanic rock resulting from subsequent cooling is also often called ''lava''. A lava flow is an outpouring of lava during an effusive eruption. (An explosive eruption, by contrast, produces a mixture of volcanic ash and other fragments called tephra, not lava flows.) The viscosity of most lava is about that of ketchup, roughly 10,000 to 100,000 times that of water. Even so, lava can flow great distances before cooling causes it to solidify, because lava exposed to air quickly develops a solid crust that insulates the remaining liquid lava, helping to keep it hot and inviscid enough to continue flowing. The word ''lava'' comes from Italian and is probably derived from the Latin word ''labes ... [...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] |
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] |
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] |
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] |
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