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Kerwan (crater)
Kerwan () is the largest confirmed impact basin and one of the largest geological features on the dwarf planet Ceres. It was discovered on February 19, 2015 from ''Dawn'' images as it approached Ceres. The crater is distinctly shallow for its size, and lacks a central peak. A central peak might have been destroyed by a 15-kilometer-wide crater at the center of Kerwan. The crater is likely to be young relative to the rest of Ceres's surface, as Kerwan has largely obliterated the cratering in the southern part of Vendimia Planitia.Marchi, S et al. “The missing large impact craters on Ceres.” Nature communications vol. 7 12257. 26 Jul. 2016, doi:10.1038/ncomms12257 Kerwan is roughly antipodal to Ahuna Mons, the largest, or at least youngest, mountain on Ceres. Seismic energy from the Kerwan-forming impact may have focused on the opposite side of Ceres, fracturing the outer layers of the crust and facilitating the movement of high-viscosity cryomagma (consisting of muddy water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceres (dwarf Planet)
Ceres (minor-planet designation: 1 Ceres) is a dwarf planet in the middle main asteroid belt between the orbits of Mars and Jupiter. It was the first known asteroid, discovered on 1 January 1801 by Giuseppe Piazzi at Palermo Astronomical Observatory in Sicily, and announced as a new planet. Ceres was later classified as an asteroid and then a dwarf planet, the only one not beyond Neptune's orbit. Ceres's diameter is about a quarter that of the Moon. Its small size means that even at its brightest it is too dim to be seen by the naked eye, except under extremely dark skies. Its apparent magnitude ranges from 6.7 to 9.3, peaking at opposition (planets), opposition (when it is closest to Earth) once every 15- to 16-month synodic period. As a result, its surface features are barely visible even with the most powerful telescopes, and little was known about it until the robotic NASA spacecraft Dawn (spacecraft), ''Dawn'' approached Ceres for its orbital mission in 2015. ''Dawn'' fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dawn (spacecraft)
''Dawn'' is a retired space probe that was launched by NASA in September 2007 with the mission of studying two of the three known protoplanets of the asteroid belt: Vesta and Ceres. In the fulfillment of that mission—the ninth in NASA's Discovery Program—''Dawn'' entered orbit around Vesta on July 16, 2011, and completed a 14-month survey mission before leaving for Ceres in late 2012. It entered orbit around Ceres on March 6, 2015. In 2017, NASA announced that the planned nine-year mission would be extended until the probe's hydrazine fuel supply was depleted. On November 1, 2018, NASA announced that ''Dawn'' had depleted its hydrazine, and the mission was ended. The derelict probe remains in a stable orbit around Ceres. ''Dawn'' is the first spacecraft to have orbited two extraterrestrial bodies, the first spacecraft to have visited either Vesta or Ceres, and the first to have orbited a dwarf planet. The ''Dawn'' mission was managed by NASA's Jet Propulsion Laboratory, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maize
Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout grass that produces cereal grain. It was domesticated by indigenous peoples in southern Mexico about 9,000 years ago from wild teosinte. Native Americans planted it alongside beans and squashes in the Three Sisters polyculture. The leafy stalk of the plant gives rise to male inflorescences or tassels which produce pollen, and female inflorescences called ears. The ears yield grain, known as kernels or seeds. In modern commercial varieties, these are usually yellow or white; other varieties can be of many colors. Maize relies on humans for its propagation. Since the Columbian exchange, it has become a staple food in many parts of the world, with the total production of maize surpassing that of wheat and rice. Much maize is used for animal feed, whether as grain or as the whole plant, which can either be baled or made into the more palatable silage. Sugar-rich varieties called sw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Crater
An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, 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. Impact craters are typically circular, though they can be elliptical in shape or even irregular due to events such as landslides. Impact craters range in size from microscopic craters seen on lunar rocks returned by the Apollo Program to simple bowl-shaped depressions and vast, 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 (planet), Mercury, Callisto (moon), Callisto, Ganymede (moon), Ganymede, and most small moons and asteroids. On other planet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dwarf Planet
A dwarf planet is a small planetary-mass object that is in direct orbit around the Sun, massive enough to be hydrostatic equilibrium, gravitationally rounded, but insufficient to achieve clearing the neighbourhood, orbital dominance like the eight classical planets of the Solar System. The prototypical dwarf planet is Pluto, which for decades was regarded as a planet before the "dwarf" concept was adopted in 2006. Dwarf planets are capable of being geologically active, an expectation that was borne out in 2015 by the ''Dawn (spacecraft), Dawn'' mission to and the ''New Horizons'' mission to Pluto. planetary geology, Planetary geologists are therefore particularly interested in them. Astronomers are in general agreement that at least the List of possible dwarf planets#Likeliest dwarf planets, nine largest candidates are dwarf planets – in rough order of diameter, , , , , , , , , and . A considerable uncertainty remains over the tenth largest candidate , which may thus be co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vendimia Planitia
Ceres is a dwarf planet in the asteroid belt that lies between the orbits of Mars and Jupiter. The IAU has adopted two themes for naming surface features on Ceres: agricultural deities for craters and agricultural festivals for everything else. As of 2020, the IAU has approved names for 151 geological features on Ceres: craters, montes, catenae, rupēs, plana, tholi, planitiae, fossae and sulci. In July 2018, NASA released a comparison of physical features found on Ceres with similar ones present on Earth. ''Piazzi'', named after Giuseppe Piazzi, the discoverer of Ceres, is a dark region southwest of Dantu crater in ground-based images that was named before ''Dawn'' arrived at Ceres. Overview of features Catenae Craters Ceres is saturated with impact crater An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, impact of a smaller object. In contrast to volcanic craters, whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ahuna Mons
Ahuna Mons () is the largest mountain on the dwarf planet and asteroid Ceres. It protrudes above the cratered terrain, is not an impact feature, and is the only mountain of its kind on Ceres. Bright streaks run top to bottom on its slopes which are thought to be salt, similar to the better known Cererian bright spots, and likely resulted from cryovolcanic activity from Ceres's interior. It is named after the traditional post-harvest festival '' Ahuna'' of the Sümi Naga people of India. In July 2018, NASA released a comparison of physical features, including Ahuna Mons, found on Ceres with similar ones present on Earth. Discovery The mountain was discovered on images taken by the ''Dawn'' spacecraft in orbit around Ceres in 2015. It is estimated to have an average height of about and a maximum height of about on its steepest side; it is about wide at the base. Origin It has been proposed that Ahuna Mons formed as a cryovolcanic dome. It is the closest cryovolcano to the S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryomagma
A cryovolcano (sometimes informally referred to as an ice volcano) is a type of volcano that erupts gases and volatile material such as liquid water, ammonia, and hydrocarbons. The erupted material is collectively referred to as ''cryolava''; it originates from a reservoir of subsurface ''cryomagma''. Cryovolcanic eruptions can take many forms, such as fissure and curtain eruptions, effusive cryolava flows, and large-scale resurfacing, and can vary greatly in output volumes. Immediately after an eruption, cryolava quickly freezes, constructing geological features and altering the surface. Although rare in the inner Solar System, past and recent cryovolcanism is common on planetary objects in the outer Solar System, especially on the icy moons of the giant planets and potentially amongst the dwarf planets as well. As such, cryovolcanism is important to the geological histories of these worlds, constructing landforms or even resurfacing entire regions. Despite this, only a few e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hopi Mythology
The Hopi maintain a complex religious and mythological tradition stretching back over centuries. However, it is difficult to definitively state what all Hopis as a group believe. Like the oral traditions of many other societies, Hopi mythology is not always told consistently and each Hopi mesa, or even each village, may have its own version of a particular story, but "in essence the variants of the Hopi myth bear marked similarity to one another." It is also not clear that the stories told to non-Hopis, such as anthropologists and ethnographers, represent genuine Hopi beliefs or are merely stories told to the curious while keeping safe the more sacred Hopi teachings. As folklorist Harold Courlander states, "there is a Hopi reticence about discussing matters that could be considered ritual secrets or religion-oriented traditions." Major deities Most Hopi creation myths, creation stories center around Tawa, the sun spirit. Tawa is the creator, and it was he who formed the "Fir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Geological Features On Ceres
Ceres is a dwarf planet in the asteroid belt that lies between the orbits of Mars and Jupiter. The IAU has adopted two themes for naming surface features on Ceres: agricultural deities for craters and agricultural festivals for everything else. As of 2020, the IAU has approved names for 151 geological features on Ceres: craters, montes, catenae, rupēs, plana, tholi, planitiae, fossae and sulci. In July 2018, NASA released a comparison of physical features found on Ceres with similar ones present on Earth. ''Piazzi'', named after Giuseppe Piazzi, the discoverer of Ceres, is a dark region southwest of Dantu crater in ground-based images that was named before ''Dawn'' arrived at Ceres. Overview of features Catenae Craters Ceres is saturated with impact crater An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, impact of a smaller object. In contrast to volcanic craters, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Craters On Asteroids
Impact may refer to: * Impact (mechanics), a large force or mechanical shock over a short period of time * Impact, Texas, a town in Taylor County, Texas, US Science and technology * Impact crater, a meteor crater caused by an impact event * Impact event, the collision of a meteoroid, asteroid or comet with Earth * Impact factor, a measure of the citations to a science or social science journal * Impact wrench, a socket wrench power tool capable of high torque Books and magazines * ''Impact'' (novel), a 2010 novel by Douglas Preston *'' Impact Press'', a former Orlando, Florida-based magazine * Impact Magazines, a former UK magazine publisher * ''Impact'' (conservative magazine), a British political magazine * ''Impact'' (British magazine), a British action film magazine * ''Impact'', a French action film magazine spun off from ''Mad Movies'' * ''Impact'' (UNESCO magazine), a former UNESCO quarterly titled ''IMPACT of science on society'' * ''Impact'' (student magazine), a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
