Epigeus (crater)
Epigeus is the largest known impact crater on Jupiter's Galilean satellite Ganymede, with a diameter of 343 km. It is 6.5% the mean equatorial diameter of Ganymede, . It is located in Marius Regio at . At the center of Epigeus, there is a 25-km-radius region of sub-radial dark-floored troughs or fractures. These troughs range from approximately 150 to 250 m across, are generally linear, and merge in dendritic or anastomosing patterns. The troughs exhibit two orthogonal preferred orientations, trending north–south and east–west. A bright, rough-textured, lobate deposit occupies the central 15 to 20 km of this region and locally surrounds troughs up to 25 km from the palimpsest center. This bright region consists of massifs 200 to 300 m across separated by 200 to 300 m. The outer ring is a complex zone corresponding to a crater diameter. The zone between those two rings is relatively smooth and it is covered in small knobs. Several lobes of this unit appear to ha ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Crater Epigeus On Ganimede
Crater may refer to: Landforms *Impact crater, a depression caused by two celestial bodies impacting each other, such as a meteorite hitting a planet *Explosion crater, a hole formed in the ground produced by an explosion near or below the surface **Subsidence crater, a depression from an underground (usually nuclear) explosion *Pit crater, a crater that forms through sinking of the surface and not as a vent for lava *Volcanic crater, a roughly circular depression in the ground caused by volcanic activity **Caldera, a large cauldron-like depression formed following the evacuation of a magma chamber/reservoir **Maar, a type of volcanic crate caused by a phreatic eruption or explosion **Volcanic crater lake, including a list of lakes that formed in a volcanic or impact crater Music * ''Crater'' (Daniel Menche and Mamiffer album), 2016 *Crater (Fission album), 2004 Places *Crati or Crater, a river of southern Italy *Crater, California, U.S. *Crater (Aden), a district of the Aden Gov ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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]   |
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Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandth the mass of the Sun. Jupiter is the List of brightest natural objects in the sky, third brightest natural object in the Earth's night sky after the Moon and Venus, and it has been observed since Pre-history, prehistoric times. It was named after the Jupiter (mythology), Roman god Jupiter, the king of the gods. Jupiter is primarily composed of hydrogen, but helium constitutes one-quarter of its mass and one-tenth of its volume. It probably has a rocky core of heavier elements, but, like the other giant planets in the Solar System, it lacks a well-defined solid surface. The ongoing contraction of Jupiter's interior generates more heat than it receives from the Sun. Because of its rapid rotation, the planet' ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Galilean Moons
The Galilean moons (), or Galilean satellites, are the four largest moons of Jupiter: Io, Europa, Ganymede, and Callisto. They were first seen by Galileo Galilei in December 1609 or January 1610, and recognized by him as satellites of Jupiter in March 1610. They were the first objects found to orbit a planet other than the Earth. They are among the largest objects in the Solar System with the exception of the Sun and the eight planets, with a radius larger than any of the dwarf planets. Ganymede is the largest moon in the Solar System, and is even bigger than the planet Mercury, though only around half as massive. The three inner moons— Io, Europa, and Ganymede—are in a 4:2:1 orbital resonance with each other. While the Galilean moons are spherical, all of Jupiter's much smaller remaining moons have irregular forms because of their weaker self-gravitation. The Galilean moons were observed in either 1609 or 1610 when Galileo made improvements to his telescope, which ena ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Ganymede (moon)
Ganymede, a satellite of Jupiter (Jupiter III), is the largest and most massive of the Solar System's moons. The ninth-largest object (including the Sun) of the Solar System, it is the largest without a substantial atmosphere (albeit not the most massive one, which is Mercury). It has a diameter of , making it 26 percent larger than the planet Mercury by volume, although it is only 45 percent as massive. Possessing a metallic core, it has the lowest moment of inertia factor of any solid body in the Solar System and is the only moon known to have a magnetic field. Outward from Jupiter, it is the seventh satellite and the third of the Galilean moons, the first group of objects discovered orbiting another planet. Ganymede orbits Jupiter in roughly seven days and is in a 1:2:4 orbital resonance with the moons Europa and Io, respectively. Ganymede is composed of approximately equal amounts of silicate rock and water. It is a fully differentiated body with an iron-rich, liq ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Marius Regio
Marius may refer to: People *Gaius Marius (157 BC-86 BC), Roman statesman, seven times consul. Arts and entertainment * ''Marius'' (play), a 1929 play by Marcel Pagnol * "Marius" (short story), a 1957 story by Poul Anderson * ''Marius'' (1931 film), a French adaptation of Pagnol's play, directed by Alexander Korda * ''Marius'' (2013 film), a French adaptation of Pagnol's play, directed by Daniel Auteuil Places * Marius (Laconia), a town of ancient Laconia, Greece * Măriuș, a village in Valea Vinului, Satu Mare County, Romania * Marius (crater), on the Moon * Marius Hills, on the Moon Other uses * Marius (name), a male given name, a Roman clan name and family name, and a modern name or surname * Marius (commando), Alain Alivon (born 1965), French Navy officer * Marius (giraffe), a giraffe euthanized at the Copenhagen Zoo in 2014 See also * * * Mario (other) * Maria (other) * Mary (other) Mary may refer to: People * Mary (name), a femini ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Anastomosis
An anastomosis (, plural anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf#Veins, leaf veins, or streams. Such a connection may be normal (such as the foramen ovale (heart), foramen ovale in a fetus's heart) or abnormal (such as the atrial septal defect#Patent foramen ovale, patent foramen ovale in an adult's heart); it may be acquired (such as an arteriovenous fistula) or innate (such as the arteriovenous shunt of a metarteriole); and it may be natural (such as the aforementioned examples) or artificial (such as a surgical anastomosis). The reestablishment of an anastomosis that had become blocked is called a reanastomosis. Anastomoses that are abnormal, whether congenital disorder, congenital or acquired, are often called fistulas. The term is used in medicine, biology, mycology, geology, and geography. Etymology Anastomosis: medical or Modern Latin, from Gre ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Palimpsest (planetary Astronomy)
A palimpsest , in planetary astronomy, is an ancient crater that has been degraded over time. They may also be referred to as "ghost craters", "degraded craters", "buried craters", or "pathological craters". Palimpsests have been identified on Mercury, the Earth, the Moon, Mars, Ganymede, Callisto, and possibly even Titan. On Mars, these features are morphologically described as craters that are "flat-floored, rimless, extremely shallow, without central peaks, and would probably represent what remains after erosion." On an icy moon of the outer Solar System, a palimpsest is a crater whose relief has disappeared due to creep of the icy surface ("viscous relaxation") or subsequent cryovolcanic outpourings, leaving a circular albedo feature, perhaps with a "ghost" of a rim. Icy surfaces of natural satellites like Callisto Callisto most commonly refers to: *Callisto (mythology), a nymph *Callisto (moon), a moon of Jupiter Callisto may also refer to: Art and entertainment *''Call ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Massif
In geology, a massif ( or ) is a section of a planet's crust that is demarcated by faults or flexures. In the movement of the crust, a massif tends to retain its internal structure while being displaced as a whole. The term also refers to a group of mountains formed by such a structure. In mountaineering and climbing literature, a massif is frequently used to denote the main mass of an individual mountain. The massif is a smaller structural unit of the crust than a tectonic plate, and is considered the fourth-largest driving force in geomorphology. The word is taken from French (in which the word also means "massive"), where it is used to refer a large mountain mass or compact group of connected mountains forming an independent portion of a range. One of the most notable European examples of a massif is the Massif Central of the Auvergne region of France. The Face on Mars is an example of an extraterrestrial massif. Massifs may also form underwater, as with the Atlanti ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Valley
A valley is an elongated low area often running between Hill, hills or Mountain, mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over a very long period. Some valleys are formed through erosion by glacier, glacial ice. These glaciers may remain present in valleys in high mountains or polar areas. At lower latitudes and altitudes, these glaciation, glacially formed valleys may have been created or enlarged during ice ages but now are ice-free and occupied by streams or rivers. In desert areas, valleys may be entirely dry or carry a watercourse only rarely. In karst, areas of limestone bedrock, dry valleys may also result from drainage now taking place cave, underground rather than at the surface. Rift valleys arise principally from tectonics, earth movements, rather than erosion. Many different types of valleys are described by geographers, using terms th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Shock Metamorphism
Shock metamorphism or impact metamorphism describes the effects of shock-wave related deformation and heating during impact events. The formation of similar features during explosive volcanism is generally discounted due to the lack of metamorphic effects unequivocally associated with explosions and the difficulty in reaching sufficient pressures during such an event. Effects Mineral microstructures Planar fractures Planar fractures are parallel sets of multiple planar cracks or cleavages in quartz grains; they develop at the lowest pressures characteristic of shock waves (~5–8 GPa) and a common feature of quartz grains found associated with impact structures. Although the occurrence of planar fractures is relatively common in other deformed rocks, the development of intense, widespread, and closely spaced planar fractures is considered diagnostic of shock metamorphism. [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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International Astronomical Union
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation. It was founded in 1919 and is based in Paris, France. The IAU is composed of individual members, who include both professional astronomers and junior scientists, and national members, such as professional associations, national societies, or academic institutions. Individual members are organised into divisions, committees, and working groups centered on particular subdisciplines, subjects, or initiatives. As of 2018, the Union had over 13,700 individual members, spanning 90 countries, and 82 national members. Among the key activities of the IAU is serving as a forum for scientific conferences. It sponsors nine annual symposia and holds a triannual General Assembly that sets policy ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |