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Caloris Basin Comparison
Caloris Planitia is a planitia, plain within a large impact basin on Mercury (planet), Mercury, informally named Caloris, about in diameter. It is one of the List of largest craters in the Solar System, largest impact basins in the Solar System. "Calor" is Latin for "heat" and the basin is so-named because the Sun is almost directly overhead every second time Mercury passes perihelion. The crater, discovered in 1974, is surrounded by the Caloris Montes, a ring of mountains approximately tall. Appearance Caloris was discovered on images taken by the ''Mariner 10'' probe in 1974. Its name was suggested by Brian O'Leary, astronaut and member of the ''Mariner 10'' imagery team. It was situated on the Terminator (solar), terminator—the line dividing the daytime and nighttime hemispheres—at the time the probe passed by, and so half of the crater could not be imaged. Later, on January 15, 2008, one of the first photos of the planet taken by the ''MESSENGER'' probe revealed the cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MESSENGER
''MESSENGER'' was a NASA robotic space probe that orbited the planet Mercury between 2011 and 2015, studying Mercury's chemical composition, geology, and magnetic field. The name is a backronym for "Mercury Surface, Space Environment, Geochemistry, and Ranging", and a reference to the messenger god Mercury from Roman mythology. ''MESSENGER'' was launched aboard a Delta II rocket in August 2004. Its path involved a complex series of flybys – the spacecraft flew by Earth once, Venus twice, and Mercury itself three times, allowing it to decelerate relative to Mercury using minimal fuel. During its first flyby of Mercury in January 2008, ''MESSENGER'' became the second mission, after Mariner 10 in 1975, to reach Mercury. ''MESSENGER'' entered orbit around Mercury on March 18, 2011, becoming the first spacecraft to do so. It successfully completed its primary mission in 2012. Following two mission extensions, the spacecraft used the last of its maneuvering propellant to deo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extensional Fault
An extensional fault is a fault caused by stretching of the Earth's crust. Stretching reduces the thickness and horizontally extends portions of the crust and/or lithosphere. In most cases such a fault is also a normal fault, but may create a shallower dip usually associated with a thrust fault. Extensional faults are generally planar. If the stress field is oriented with the maximum stress perpendicular to the Earth's surface, extensional faults will create an initial dip of the associated beds of about 60° from the horizontal. The faults will typically extend down to the base of the seismogenic layer In geophysics and seismology, the seismogenic layer covers the range of depths within the crust or lithosphere in which most earthquakes originate. The thickness is heavily dependent on location. For oceanic crust, the seismogenic layer thicknes .... As crustal stretching continues, the faults will rotate, resulting in steeply-dipping fault blocks between them. See also * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Planetary Society
The Planetary Society is an American internationally-active non-governmental nonprofit organization. It is involved in research, public outreach, and political space advocacy Space advocacy is supporting or advocating for a human use of outer space. Purposes advocated can reach from space exploration, or commercial use of space to even space settlement. There are many different individuals and organizations dedicat ... for engineering projects related to astronomy, planetary science, and space exploration. It was founded in 1980 by Carl Sagan, Bruce C. Murray, Bruce Murray, and Louis Friedman, and has about 60,000 members from more than 100 countries around the world. The Society is dedicated to the exploration of the Solar System, the search for near-Earth objects, and the search for extraterrestrial life. The society's mission is stated as: "Empowering the world’s citizens to advance space science and exploration." The Planetary Society is a strong advocate for space ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antipodal Point
In mathematics, antipodal points of a sphere are those diametrically opposite to each other (the specific qualities of such a definition are that a line drawn from the one to the other passes through the center of the sphere so forms a true diameter). This term applies to opposite points on a circle or any n-sphere. An antipodal point is sometimes called an antipode, a back-formation from the Greek loan word ''antipodes'', meaning "opposite (the) feet", as the true word singular is ''antipus''. Theory In mathematics, the concept of ''antipodal points'' is generalized to spheres of any dimension: two points on the sphere are antipodal if they are opposite ''through the centre''; for example, taking the centre as origin, they are points with related vectors v and −v. On a circle, such points are also called diametrically opposite. In other words, each line through the centre intersects the sphere in two points, one for each ray out from the centre, and these two poin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury Weird Terrain
Mercury commonly refers to: * Mercury (planet), the nearest planet to the Sun * Mercury (element), a metallic chemical element with the symbol Hg * Mercury (mythology), a Roman god Mercury or The Mercury may also refer to: Companies * Mercury (toy manufacturer), a brand of diecast toy cars manufactured in Italy * Mercury Communications, a British telecommunications firm set up in the 1980s * Mercury Drug, a Philippine pharmacy chain * Mercury Energy, an electricity generation and retail company in New Zealand * Mercury Filmworks, a Canadian independent animation studio * Mercury General, a multiple-line American insurance organization * Mercury Interactive, a software testing tools vendor * Mercury Marine, a manufacturer of marine engines, particularly outboard motors * Mercury Systems, a defense-related information technology company Computing * Mercury (programming language), a functional logic programming language * Mercury (metadata search system), a data search system f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mare Crisium
Mare Crisium (Latin ''crisium'', the "Sea of Crises") is a lunar mare located in the Moon's Crisium basin, just northeast of Mare Tranquillitatis. The basin is of the Pre-Imbrian period, 4.55 to 3.85 billion years ago. Characteristics Mare Crisium is in diameter, and in area. It has a very flat floor, with a ring of wrinkle ridges (''dorsa'') toward its outer boundaries. These are Dorsa Tetyaev, Dorsum Oppel, Dorsum Termier, and Dorsa Harker. The cape-like feature protruding into the southeast of the mare is Promontorium Agarum. On the western rim of the mare is the palimpsest Yerkes, and Lick to the southeast is similar. The crater Picard is located just to the east of Yerkes, and northwest of Picard are the craters Peirce and Swift. The ray system of the crater Proclus overlie the northwestern mare. Mare Anguis can be seen northeast of Mare Crisium. A mass concentration (mascon), or gravitational high, was identified in the center of Mare Crisium from Doppler tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Concentration (astronomy)
In astronomy, astrophysics and geophysics, a mass concentration (or mascon) is a region of a planet's or moon's crust that contains a large positive gravity anomaly. In general, the word "mascon" can be used as a noun to refer to an excess distribution of mass on or beneath the surface of an astronomical body (compared to some suitable average), such as is found around Hawaii on Earth. However, this term is most often used to describe a geologic structure that has a positive gravitational anomaly associated with a feature (e.g. depressed basin) that might otherwise have been expected to have a negative anomaly, such as the "mascon basins" on the Moon. Lunar and Martian mascons The Moon is the most gravitationally "lumpy" major body known in the Solar System. Its largest mascons can cause a plumb bob to hang about a third of a degree off vertical, pointing toward the mascon, and increase the force of gravity by one-half percent. Typical examples of mascon basins on the Moon are t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mare Orientale
Mare Orientale (Latin ''orientāle'', the "eastern sea") is a lunar mare. It is located on the western border of the near side and far side of the Moon, and is difficult to see from an Earthbound perspective. Images from spacecraft have revealed it to be one of the most striking large scale lunar features, resembling a target ring bullseye. Geology During the 1960s, rectified images of Mare Orientale by Gerard Kuiper at the Lunar and Planetary Laboratory gave rise to the notion of it being an impact crater. The structure, with the flat plain of the mare in the center, is about across and was formed by the impact of an asteroid-sized object, possibly in diameter and travelling at . Compared with most other lunar basins, Mare Orientale is less flooded by mare basalts, so that much of the basin structure is visible. The basalt in the central portion of the Orientale basin is probably less than in thickness which is much less than mare basins on the Earth-facing side of the Moon. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mare Imbrium
Mare Imbrium (Latin ''imbrium'', the "Sea of Showers" or "Sea of Rains", "Sea of Tears") is a vast lava plain within the Imbrium Basin on the Moon and is one of the larger craters in the Solar System. The Imbrium Basin formed from the collision of a proto-planet during the Late Heavy Bombardment. Basaltic lava later flooded the giant crater to form the flat volcanic plain seen today. The basin's age has been estimated using uranium–lead dating methods to approximately 3.9 billion years ago, and the diameter of the impactor has been estimated to be 250 ± 25 km. The Moon's maria (plural of mare) have fewer features than other areas of the Moon because molten lava pooled in the craters and formed a relatively smooth surface. Mare Imbrium is not as flat as it was originally thought, because later events have altered its surface. Origin Mare Imbrium formed when a proto-planet from the asteroid belt collided with the moon during the Late Heavy Bombardment. The impact i ... [...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] |
Universe Today
Universe Today (U.T.) is a popular North American-based non-commercial space and astronomy news website. The domain was registered on December 30, 1998, and the website went live in March 1999, founded by Canadian Fraser Cain. The ''Universe Today'' assumed its current form on July 24, 2003, featuring astronomy news and space-related issues. By early September 2005, the forum section merged with ''Bad Astronomy'' as a combined site with the BAUT forum. During April 2011, the Association of British Science Writers noted that ''Universe Today'' decided not to make preparations for reporting on embargoed stories until they are public knowledge. Emily Lakdawalla said that she relies on ''Universe Today'' and ''Bad Astronomy'' to "give ... an independent look at big news stories". Publications ''Universe Today'' has published two books, which are available both as e-books and on physical media: * * See also * ''Astronomy Cast'' * ''Space.com'' * ''The Space Show ''The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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