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Encyclopedia > Impact crater

In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with larger body. In most common usage, the term is used for the approximately circular depression in the surface of a planet, moon or other solid body in the Solar System, formed by the hyper-velocity impact of a smaller body with the surface. Impact craters typically have raised rims, and they range from small, simple, bowl-shaped depressions to large, complex, multi-ringed, impact basins. Meteor Crater is perhaps the best-known example of a small impact crater on the Earth. Image File history File links Emblem-important. ... Description: The prominent Tycho crater on the Moon. ... Description: The prominent Tycho crater on the Moon. ... Tycho is a prominent lunar impact crater located in the southern lunar highlands. ... This article is about Earth as a planet. ... This article is about Earths moon. ... The National Aeronautics and Space Administration (NASA) (IPA [ˈnæsə]) is an agency of the United States government, responsible for the nations public space program. ... For meteorite-created craters in general, see Impact crater. ... This article needs to be wikified. ... This article is about the astronomical term. ... A natural satellite is an object that orbits a planet or other body larger than itself and which is not man-made. ... This article is about the Solar System. ... Hypervelocity is usually refered to a very high velocity, such as over 10,000 feet per second. ... For other uses, see Collision (disambiguation). ... For meteorite-created craters in general, see Impact crater. ...


Impact craters provide the dominant landforms 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, Mars, Europa, Io and Titan, visible impact craters are less common because they become eroded, buried or transformed by tectonics over time. Where such processes have destroyed most of the original crater topography, the terms impact structure or astrobleme are more commonly used. In early literature, before the significance of impact cratering was widely recognised, the terms cryptoexplosion or cryptovolcanic structure were often used to describe what are now recognised as impact-related features on Earth. This article is about Earths moon. ... This article is about the planet. ... There is also an asteroid named 204 Kallisto. ... This article is about the natural satellite of Jupiter. ... For other uses, see Asteroid (disambiguation). ... This article is about Earth as a planet. ... For other uses, see Venus (disambiguation). ... Adjectives: Martian Atmosphere Surface pressure: 0. ... Apparent magnitude: 5. ... Atmosphere Surface pressure: trace Composition: 90% sulfur dioxide Io (eye-oe, IPA: , Greek Ῑώ) is the innermost of the four Galilean moons of Jupiter and, with a diameter of 3,642 kilometers, is the fourth largest moon in the Solar System. ... Titan (, from Ancient Greek Τῑτάν) or Saturn VI is the largest moon of Saturn and the only moon known to have a dense atmosphere. ... For morphological image processing operations, see Erosion (morphology). ... The tectonic plates of the world were mapped in the second half of the 20th century. ... The term impact structure is closely related to the terms impact crater or meteorite impact crater, and is used in cases where erosion or burial have destroyed or masked the original topographic feature with which we normally associate the term crater. ... In geology, a cryptoexplosion structure is any roughly circular structure of unknown origin that was likely caused by a sudden, explosive release of energy resulting in notable localized deformation of rock strata. ...


In the early Solar System, rates of impact cratering were much higher than today. The large multi-ringed impact basins, with diameters of hundreds of kilometres or more, retained for example on Mercury and the Moon, record a period of intense early bombardment in the inner Solar System that ended about 3.8 billion years ago. Since that time, the rate of crater production on Earth has been considerably lower, but it is appreciable nonetheless; Earth experiences from one to three impacts large enough to produce a 20 km diameter crater about once every million years on average. This indicates that there should be far more relatively young craters on the planet than have been discovered so far. The Late Heavy Bombardment (LHB) was a period approximately 3. ...


Although the Earth’s active surface processes quickly destroy the impact record, about 170 terrestrial impact craters have been identified. These range in diameter from a few tens of meters up to about 300 km, and they range in age from recent times (e.g. the Sikhote-Alin craters in Russia witnessed in 1947) to more than two billion years, though most are less than 200 million years old because geological processes tend to obliterate older craters. They are also selectively found in the stable interior regions of continents. Few under sea craters have been discovered because of the difficulty of surveying the sea floor, the rapid rate of change of the ocean bottom, and the subduction of the ocean floor into the Earth's interior by processes of plate tectonics. A 1. ... World geologic provinces. ... Categories: Geology stubs | Plate tectonics ... The tectonic plates of the world were mapped in the second half of the 20th century. ...

Contents

History

Eugene Shoemaker, pioneer impact crater researcher, here at a stereoscopic microscope used for asteroid discovery
Eugene Shoemaker, pioneer impact crater researcher, here at a stereoscopic microscope used for asteroid discovery

Daniel Barringer (1860-1929) was one of the first to identify an impact crater, Meteor Crater in Arizona; to crater specialists the site is referred to as Barringer Crater in his honor. Initially Barringer's ideas were not widely accepted, and even when the origin of Meteor Crater was finally acknowledged, the wider implications for impact cratering as a significant geological process on Earth were not. USGS photo of Eugene Shoemaker. ... USGS photo of Eugene Shoemaker. ... Daniel Moreau Barringer (1860 – 1929) is best known for being the first person to prove the existence of a meteorite crater on Earth, the Barringer Meteorite Crater, or Meteor Crater, in Arizona. ... For meteorite-created craters in general, see Impact crater. ... Official language(s) English Spoken language(s) English 74. ... The Barringer Crater, also known as the Meteor Crater, is a famous impact crater created by a meteorite, located about 55 kilometers east of Flagstaff in the northern Arizona desert (USA). ...


In the 1920s, the American geologist Walter H. Bucher studied a number of sites now recognized as impact craters in the USA. He concluded they had been created by some great explosive event, but believed that this force was probably volcanic in origin. However, in 1936, the geologists John D. Boon and Claude C. Albritton Jr. revisited Bucher's studies and concluded that the craters that he studied were probably formed by impacts. Dr. Walter Hermann Bucher (March 12, 1889–February 17, 1965) was a German-American geologist and paleontologist. ... Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station For other uses, see Volcano (disambiguation). ...


The concept of impact cratering remained more or less speculative until the 1960s. At this time a number of researchers, most notably Eugene M. Shoemaker, conducted detailed studies of a number of craters and recognized clear evidence that they had been created by impacts, specifically identifying the shock-metamorphic effects uniquely associated with impact events, of which the most familiar is shocked quartz. Eugene Shoemaker at a stereoscopic microscope used for asteroid discovery Eugene Merle Shoemaker (or Gene Shoemaker) (April 28, 1928 – July 18, 1997) was one of the founders of the fields of planetary science and is best known for co-discovering the Comet Shoemaker-Levy 9 with his wife Carolyn Shoemaker... Shocked quartz is a form of quartz that has a microscopic structure that is different from normal quartz. ...


Armed with the knowledge of shock-metamorphic features, Carlyle S. Beals and colleagues at the Dominion Observatory in Victoria, British Columbia, Canada, and Wolf von Engelhardt of the University of Tübingen in Germany began a methodical search for impact craters. By 1970, they had tentatively identified more than 50. Although their work was controversial, the American Apollo Moon landings, which were in progress at the time, provided supportive evidence by recognizing the rate of impact cratering on the Moon. Processes of erosion on the Moon are minimal and so craters persist almost indefinitely. Since the Earth could be expected to have roughly the same cratering rate as the Moon, it became clear that the Earth had suffered far more impacts than could be seen by counting evident craters. The Dominion Observatory building The Dominion Observatory was an astronomical observatory in Ottawa, Canada that operated from 1905 to 1970. ... This article is about the city of Victoria. ... Eberhard Karls University of Tübingen (German: Eberhard-Karls-Universität Tübingen) is a state-supported university located on the Neckar river, in the city of Tübingen, Baden-Württemberg, Germany. ... This article is about the series of human spaceflight missions. ... This article is about Earths moon. ...


Crater formation

A laboratory simulation of an impact event and crater formation

Impact cratering involves high velocity collisions between solid objects, typically much greater than the velocity of sound in those objects. Such hyper-velocity impacts produce physical effects such as melting and vaporization, that do not occur in familiar sub-sonic collisions. On Earth, ignoring the slowing effects of travel through the atmosphere, the lowest impact velocity with an object from space is equal to the gravitational escape velocity of about 11 km/s. The fastest impacts occur at more than 70 km/s, calculated by summing the escape velocity from Earth, the escape velocity from the Sun at the Earth's orbit, and the motion of the Earth around the Sun. The median impact velocity on Earth is about 20 to 25 km/s. This page is about the physical speed of sound waves in a medium. ... In physics, melting is the process of heating a solid substance to a point (called the melting point) where it turns into a liquid. ... Vaporization redirects here. ... Space Shuttle Atlantis launches on mission STS-71. ... Two bodies with a slight difference in mass orbiting around a common barycenter. ... This article is about the statistical concept. ...


Impacts at these high speeds produce shockwaves in solid materials, and both impactor and the material impacted are rapidly compressed to high density. Following initial compression, the high-density, over-compressed region rapidly depressurizes, exploding violently, to set in train the sequence of events that produces the impact crater. Impact-crater formation is therefore more closely analogous to cratering by high explosives than by mechanical displacement. Indeed, the energy density of some material involved in the formation of impact craters is many times higher than that generated by high explosives. Since craters are caused by explosions, they are nearly always circular – only very low-angle impacts cause significantly elliptical craters. Introduction The shock wave is one of several different ways in which a gas in a supersonic flow can be compressed. ... Physical compression is the result of the subjection of a material to compressive stress, resulting in reduction of volume. ... This article is concerned solely with chemical explosives. ... Energy density is the amount of energy stored in a given system or region of space per unit volume, or per unit mass, depending on the context. ...


It is convenient to divide the impact process conceptually into three distinct stages: (1) initial contact and compression, (2) excavation, (3) modification and collapse. In practice, there is overlap between the three processes with, for example, the excavation of the crater continuing in some regions while modification and collapse is already underway in others.


Contact and compression

In the absence of atmosphere, the impact process begins when the impactor first touches the target surface. This contact accelerates the target and decelerates the impactor. Because the impactor is moving so rapidly, the rear of the object moves a significant distance during the short-but-finite time taken for the deceleration to propagate across the impactor. As a result, the impactor is compressed, its density rises, and the pressure within it increases dramatically. Peak pressures in large impacts exceed 1 TPa to reach values more usually found deep in the interiors of planets, or generated artificially in nuclear explosions. For other uses, see Atmosphere (disambiguation). ... Acceleration is the time rate of change of velocity and/or direction, and at any point on a velocity-time graph, it is given by the slope of the tangent to the curve at that point. ... This article is about pressure in the physical sciences. ... tera- (symbol: T) is a prefix in the SI system of units denoting 1012, or 1 000 000 000 000. ... For other uses, see Pascal. ... A nuclear explosion (nuclear detonation) has occurred: twice using a nuclear weapon during war (during World War II, the atomic bombings of Hiroshima and Nagasaki) many times testing a nuclear weapon a series of tests of nuclear explosives for construction purposes; see Operation Plowshare Potential other applications (not yet applied...


In physical terms, a supersonic shockwave initiates from the point of contact. As this shockwave expands, it decelerates and compresses the impactor, and it accelerates and compresses the target. Stress levels within the shockwave far exceeds the strength of solid materials; consequently, both the impactor and the target close to the impact site are irreversibly damaged. Many crystalline minerals can be transformed into higher-density phases by shockwaves, for example the common mineral quartz can be transformed into the higher-pressure forms coesite and stishovite. Many other shock-related changes take place within both impactor and target as the shockwave passes through, and some of these changes can be used as diagnostic tools to determine whether particular geological features were produced by impact cratering. A United States Navy F/A-18E/F Super Hornet in transonic flight. ... Coesite is a form of silicon dioxide that is formed when very high pressure (2–3 gigapascals) and moderately high temperature (700 °C) are applied to quartz. ... Stishovite is a form of silicon dioxide that is formed at very high pressure (~ 100 kbar) and temperature (> 1200 ° C), so far as is known only in meteorite impact craters and their ejecta. ...


As the shockwave decays, the shocked region decompresses towards more usual pressures and densities. The damage produced by the shockwave raises the temperature of the material, and in all but the smallest impacts this increase in temperature is sufficient to melt the impactor, and in larger impacts to vaporize most of it and to melt large volumes of the target. As well as being heated, the target near the impact is accelerated by the shockwave, and it remains moving away from the impact behind the decaying shockwave.


Excavation

Contact, compression, decompression, and the passage of the shockwave all occur within a few tenths of a second for a large impact. The subsequent excavation of the crater occurs more slowly, and during this stage the flow of material is largely sub-sonic. During excavation, the crater grows as the accelerated target moves away from the impact point. The motion is initially downwards and outwards, and with time this evolves to becomes outwards and upwards. The flow initially produces an approximately hemispherical cavity. The cavity continues to grow, eventually producing a paraboloid (bowl-shaped) crater in which the centre has been pushed down, a significant volume of material has been ejected, and a topographically elevated crater rim has been pushed up. When this cavity has reached its maximum size, it is called the transient cavity.

Herschel Crater on Saturn's moon Mimas
Herschel Crater on Saturn's moon Mimas


The depth of the transient cavity is typically a quarter to a third of its diameter. Ejecta thrown out of the crater does not include material excavated from the full depth of the transient cavity - typically the depth of maximum excavation is only about a third of the total depth. As a result, about one third of the volume of the transient crater is formed by the ejection of material, and the remaining two thirds is formed by the displacement of material downwards, outwards and upwards, to form the elevated rim. For impacts into highly porous materials, a significant crater volume may also be formed by the permanent compaction of the pore space. Such compaction craters may be important on many asteroids, comets and small moons. Image File history File links Mimas, Saturns moon. ... Image File history File links Mimas, Saturns moon. ... Herschel is a huge crater on the Saturnian moon Mimas. ... Mimas (mee-məs or mye-məs, IPA: , Greek Μίμᾱς, rarely Μίμανς) is a moon of Saturn that was discovered in 1789 by William Herschel. ... In volcanology, ejecta consists of particles that came out of a volcanic vent, traveled though the air or under water, and fell back on the ground surface or on the ocean floor. ...


In large impacts, as well as material displaced and ejected to form the crater, significant volumes of target material may be melted and vaporized together with the original impactor. Some of this impact melt rock may be ejected, but most of it remains within the transient crater, initially forming a layer of impact melt coating the interior of the transient cavity. In contrast, the hot dense vaporized material expands rapidly out of the growing cavity, carrying some solid and molten material within it as it does so. As this hot vapor cloud expands, it rises and cools much like the archetypal mushroom cloud generated by large nuclear explosions. In large impacts, the expanding vapor cloud may rise to many times the scale height of the atmosphere, effectively expanding into free space.


Most material ejected from the crater is deposited within a few crater radii, but a small fraction may travel large distances at high velocity, and in large impacts it may exceed escape velocity and leave the impacted planet or moon entirely. The majority of the fastest material is ejected from close to the centre of impact, and the slowest material is ejected close to the rim at low velocities to form an overturned coherent flap of ejecta immediately outside the rim. As ejecta escapes from the growing crater, it forms an expanding curtain in the shape of an inverted cone; the trajectory of individual particles within the curtain is thought to be largely ballistic. Space Shuttle Atlantis launches on mission STS-71. ...


Small volumes of un-melted and relatively un-shocked material may be spalled at very high relative velocities from the surface of the target and from the rear of the impactor. Spalling provides a potential mechanism whereby material may be ejected into inter-planetary space largely undamaged, and whereby small volumes of the impactor may be preserved undamaged even in large impacts. Small volumes of high-speed material may also be generated early in the impact by jetting. This occurs when two surfaces converge rapidly and obliquely at a small angle, and high-temperature highly shocked material is expelled from the convergence zone with velocities that may be several times larger than the impact velocity. Very high speed photography of a small projectile impacting a thin aluminium plate at 7000 m/s. ...


Modification and collapse

In most circumstances, the transient cavity is not stable: it collapses under gravity. In small craters, less than about 4 km diameter on Earth, there is some limited collapse of the crater rim coupled with debris sliding down the crater walls and drainage of impact melts into the deeper cavity. The resultant structure is called a simple crater, and it remains bowl-shaped and superficially similar to the transient crater. In simple craters, the original excavation cavity is overlain by a lens of collapse breccia, ejecta and melt rock, and a portion of the central crater floor may sometimes be flat. Breccia, derived from the Latin word for broken, is a sedimentary rock composed of angular fragments in a matrix that may be of a similar or a different material. ...

Multi-ringed impact basin Valhalla on Jupiter's moon Callisto
Multi-ringed impact basin Valhalla on Jupiter's moon Callisto

Above a certain threshold size, which varies with planetary gravity, the collapse and modification of the transient cavity is much more extensive, and the resulting structure is called a complex crater. The collapse of the transient cavity is driven by gravity, and involves both the uplift of the central region and the inward collapse of the rim. The central uplift is not the result of elastic rebound which is a process in which a material with elastic strength attempts to return to its original geometry; rather the collapse is a process in which a material with little or no strength attempts to return to a state of gravitational equilibrium. Download high resolution version (1196x714, 370 KB)Valhalla crater on Callisto. ... Download high resolution version (1196x714, 370 KB)Valhalla crater on Callisto. ... There is also an asteroid named 204 Kallisto. ...


Complex craters have uplifted centers, and they have typically broad flat shallow crater floors, and terraced walls. At the largest sizes, one or more exterior or interior rings may appear, and the structure may be labeled an impact basin rather than an impact crater. Complex-crater morphology on rocky planets appears to follow a regular sequence with increasing size: small complex craters with a central topographic peak are called central peak craters, for example Tycho; intermediate-sized craters, in which the central peak is replaced by a ring of peaks, are called peak-ring craters, for example Schrodinger; and the largest craters contain multiple concentric topographic rings, and are called multi-ringed basins, for example Orientale. On icy as opposed to rocky bodies, other morphological forms appear which may have central pits rather than central peaks, and at the largest sizes may contain very many concentric rings – Valhalla on Callisto is the type example of the latter. Tycho is a prominent lunar impact crater located in the southern lunar highlands. ... 1967 photograph made by NASAs Lunar Orbiter 4 Like a target ring bulls-eye, the lunar mare Mare Orientale (the eastern sea) is one of the most striking large scale lunar features. ... Valhalla crater, on Callisto Valhalla is the largest impact crater on Jupiters moon Callisto. ...


Identifying impact craters

Some volcanic features can resemble impact craters, and brecciated rocks are associated with other geological formations besides impact craters. Non-explosive volcanic craters can usually be distinguished from impact craters by their irregular shape and the association of volcanic flows and other volcanic materials. An exception is that impact craters on Venus often have associated flows of melted material. Breccia, derived from the Latin word for broken, is a sedimentary rock composed of angular fragments in a matrix that may be of a similar or a different material. ... Clastic rocks refers to rocks formed from fragments of pre-existing rock. ...


The distinctive mark of an impact crater is the presence of rock that has undergone shock-metamorphic effects, such as shatter cones, melted rocks, and crystal deformations. The problem is that these materials tend to be deeply buried, at least for simple craters. They tend to be revealed in the uplifted center of a complex crater, however. A conical fragment of rock with regular thin grooves (striae) that radiate from the top (apex) of the cone. ...


Impacts produce distinctive "shock-metamorphic" effects that allow impact sites to be distinctively identified. Such shock-metamorphic effects can include:

  • A layer of shattered or "brecciated" rock under the floor of the crater. This layer is called a "breccia lens".
  • Shatter cones, which are chevron-shaped impressions in rocks. Such cones are formed most easily in fine-grained rocks.
  • High-temperature rock types, including laminated and welded blocks of sand, spherulites and tektites, or glassy spatters of molten rock. The impact origin of tektites has been questioned by some researchers; they have observed some volcanic features in tektites not found in impactites. Tektites are also drier (contain less water) than typical impactites. While rocks melted by the impact resemble volcanic rocks, they incorporate unmelted fragments of bedrock, form unusually large and unbroken fields, and have a much more mixed chemical composition than volcanic materials spewed up from within the Earth. They also may have relatively large amounts of trace elements that are associated with meteorites, such as nickel, platinum, iridium, and cobalt. Note: it is reported in the scientific literature that some "shock" features, such as small shatter cones, which are often reported as being associated only with impact events, have been found in terrestrial volcanic ejecta.
  • Microscopic pressure deformations of minerals. These include fracture patterns in crystals of quartz and feldspar, and formation of high-pressure materials such as diamond, derived from graphite and other carbon compounds, or stishovite and coesite, varieties of shocked quartz.

Craters can also be created from underground nuclear explosions. One of the most crater-pocked sites on the planet is the Nevada Test Site, where a number of craters were purposely made during its years as a center for nuclear testing (see, for example, Operation Plowshare). Breccia, derived from the Latin word for broken, is a sedimentary rock composed of angular fragments in a matrix that may be of a similar or a different material. ... Spherulites, in petrology, are small, rounded bodies that commonly occur in vitreous igneous rocks. ... A tektite Tektites (from Greek tektos, molten) are natural glass objects, up to a few centimeters in size, which — according to most scientists — have been formed by the impact of large meteorites on Earths surface, although a few researchers favor an origin from the Moon as volcanic ejecta. ... Coesite is a form of silicon dioxide that is formed when very high pressure (2–3 gigapascals) and moderately high temperature (700 °C) are applied to quartz. ... Shocked quartz is a form of quartz that has a microscopic structure that is different from normal quartz. ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 kilometers (11 mi) above the hypocenter A nuclear weapon derives its destructive force from nuclear reactions of fusion or fission. ... The Nevada Test Site is a United States Department of Energy reservation located in Nye County, Nevada, about 65 miles (105 km) northwest of the City of Las Vegas, near . ... Preparation for an underground nuclear test at the Nevada Test Site in the 1980s. ... The 1962 Sedan plowshares shot displaced 12 million tons of earth and created a crater 320 feet (97. ...


Lunar crater categorization

In 1978, Chuck Wood and Leif Andersson of the Lunar & Planetary Lab devised a system of categorization of lunar impact craters. They used a sampling of craters that were relatively unmodified by subsequent impacts, then grouped the results into five broad categories. These successfully accounted for about 99% of all lunar impact craters.


The LPC Crater Types were as follows:

  • ALC — small, cup-shaped craters with a diameter of about 10 km or less, and no central floor. The archetype for this category is 'Albategnius C'.
  • BIO — similar to an ALC, but with small, flat floors. Typical diameter is about 15 km. The lunar crater archetype is Biot.
  • SOS — the interior floor is wide and flat, with no central peak. The inner walls are not terraced. The diameter is normally in the range of 15-25 km. The archetype is Sosigenes crater.
  • TRI — these complex craters are large enough so that their inner walls have slumped to the floor. They can range in size from 15-50 km in diameter. The archetype crater is Triesnecker.
  • TYC — these are larger than 50 km, with terraced inner walls and relatively flat floors. They frequently have large central peak formations. Tycho crater is the archetype for this class.

Beyond a couple of hundred kilometers diameter, the central peak of the TYC class disappear and they are classed as basins. For other uses, see Archetype (disambiguation). ... Albategnius is an ancient lunar impact crater located in the central highlands. ... Biot is a small, bowl-shaped lunar crater located in the southern reaches of the Mare Fecunditatis. ... Sosigenes is a lunar impact crater on the west edge of Mare Tranquillitatis. ... Triesnecker is a prominent lunar impact crater that is located in the Sinus Medii, near the central part of the Moons near side. ... Tycho is a prominent lunar impact crater located in the southern lunar highlands. ...


Lists of craters

. ... This is a list of named craters on Mercury. ... This is a list of the craters on the Moon. ... There are hundreds of thousands of craters on Mars, but only some of them have names. ... This is a list of geological features on Phobos and Deimos, the moons of Mars. ... In addition to the large Galilean moons, Jupiter is orbited by nearly sixty smaller moons, but only two of them, Amalthea and Thebe, have been imaged at sufficient resolution for surface features to become apparent. ... The surface of Jupiters moon, Europa, is very young, geologically speaking, and as a result there are very few craters. ... Ganymede is the largest moon in the solar system, and thus has many craters covering its hard surface. ... Callisto, one of the many moons of Jupiter, is the most heavily cratered moon in the solar system. ... This is list of named geological features on Janus, Epimetheus and Phoebe. ... This is a list of named geological features on Mimas. ... This is a list of named geological features on Enceladus. ... This is a list of named geological features on Tethys. ... This is a list of named geological features on Dione. ... This is a list of named geological features on Rhea. ... This is a list of named geological features on Iapetus. ... This is a list of named craters on Puck. ... This is a list of named geological features on Miranda. ... This is a list of named geological features on Ariel. ... This is a list of named craters on Umbriel. ... This is a list of named geological features on Titania. ... This is a list of named geological features (mostly craters) on Oberon. ... This is a list of named geological features, of various kinds, on Triton. ...

Notable impact craters on Earth

See the Earth Impact Database,[1] a website concerned with over 170 identified impact craters on the Earth. . ... Aorounga is a meteor crater in Chad, Africa. ... The Barringer Crater, also known as the Meteor Crater, is a famous impact crater created by a meteorite, located about 55 kilometers east of Flagstaff in the northern Arizona desert (USA). ... Beyenchime-Salaatin is a meteor crater in Russia. ... Bosumtwi is a meteor crater in Ghana. ... The Chesapeake Bay Impact Crater was formed by the impact of an extraterrestrial bolide that hit about 35. ... Radar topography reveals the 180 kilometer (112 mile) wide ring of the crater (image courtesy NASA/JPL-Caltech) Chicxulub Crater (IPA: ) (cheek-shoo-LOOB) is an ancient impact crater buried underneath the Yucatán Peninsula, with its center located approximately underneath the town of Chicxulub, Yucatán, Mexico. ... Clearwater Lakes are circular lake twins and a double meteor crater in Quebec, Canada. ... Connolly Basin is a meteor crater in Western Australia, Australia. ... Deep Bay is a meteor crater in Saskatchewan, Canada. ... Gosses Bluff crater photographed from the ISS. Gosses Bluff (Gosses Bluff) is an impact crater in Northern Territory, Australia. ... Synthetic aperture radar image of Haughton crater The Haughton impact crater is located on Devon Island, Nunavut, Canada. ... The main crater is nearly circular. ... Kara-Kul is a lake formed inside a meteor crater in Tajikistan. ... Kebira Crater Kebira Crater is an impact crater (astrobleme) in the Sahara. ... Lonar crater in the Buldhana district of Maharashtra state, India is the largest crater in basaltic rock. ... Mahuika crater is a submarine bolide impact crater, 20±2 kilometers wide and over 153 meters deep, on the New Zealand continental shelf at 48. ... Manic-cinq dam, primary dam on the Manicouagan Reservoir Manicouagan Reservoir (also Lake Manicouagan) is an annular lake in northern Quebec, Canada, the remnant of an impact crater or astrobleme made approximately 212 million years ago, towards the end of the Triassic period. ... The Manson impact crater is near the site of Manson, Iowa where an asteroid or comet nucleus struck the Earth during the Cretaceous Period, 74 million years ago. ... Mistastin Lake crater. ... Morokweng is a meteor crater in South Africa. ... The Nördlinger Ries is a depression in western Bavaria, Germany, located north of the Danube in the district of Donau-Ries. ... Panther Mountain is one of the Catskill High Peaks, located in the Town of Shandaken in Ulster County, New York. ... Popigai crater The Popigai crater in Siberia, Russia is tied with Manicouagan Reservoir as the 4th largest impact crater on Earth. ... The Rio Cuarto craters are a group of depressions located in Argentina at lattitude S 32° 52, longitude W 64° 14 There is currently some controversy as to whether these structures are actually produced by impacts, or by aeolian surficial processes, which form many similar features in that region; this... Rochechouart is an impact crater in France. ... Roter Kamm impact crater Roter Kamm is a meteorite crater in Namibia. ... There is also a Shoemaker crater at the south pole of the Moon. ... Shunak is a meteor crater in Kazakhstan. ... Siljan, in Dalecarlia in central Sweden, is Swedens sixth largest lake. ... Approximate location of the Silverpit crater The Silverpit crater is a sub-sea structure under the North Sea off the coast of the United Kingdom. ... This article or section does not cite any references or sources. ... Vredefort crater is the largest verified impact crater on Earth. ... The 19 km-diameter (12 mi) circular Weaubleau-Osceola structure is discernable in the drainage patterns of this shaded-relief image. ... Map of Antarctica, with Wilkes Land slightly to the right The Wilkes Land crater is a proposed name for a 300 mile (500 km) -wide geological feature, located in Wilkes Land, Antarctica, and centered at , that has been explained as an impact crater. ... Wolfe Creek is a meteor crater (astrobleme) in Western Australia, Australia. ... Woodleigh is a meteor crater in Western Australia. ... Yarrabubba is a meteor crater in Western Australia. ... The Earth Impact Database is the authoritative source for information on confirmed impact structures or craters on Earth. ...


Some extraterrestrial craters

The Caloris Basin, also called Caloris Planitia, is an impact crater, on Mercury, which is ~1350km in diameter. ... NASA image of Hellas Planitia Hellas Planitia, also known as the Hellas Impact Basin, is a roughly circular impact crater located in the southern hemisphere of the planet Mars. ... 1967 photograph made by NASAs Lunar Orbiter 4 Like a target ring bulls-eye, the lunar mare Mare Orientale (the eastern sea) is one of the most striking large scale lunar features. ... Petrach is a crater on Mercury. ... The Skinakas Basin is the informal name given to a structure on Mercury that appears to be an extremely large impact basin. ... The South Pole-Aitken basin is an impact crater on Earths Moon. ... Herschel is a huge crater on the Saturnian moon Mimas. ...

Largest named craters in the Solar System

  1. South Pole-Aitken basin - Moon - Diameter: 2,500 km
  2. Hellas Basin - Mars - Diameter: 2,100 km
  3. "Skinakas Basin" - Mercury - Diameter: ~1,600 km
  4. Caloris Basin - Mercury - Diameter: 1,550 km
  5. Mare Imbrium - Moon - Diameter: 1,100 km
  6. Isidis Planitia - Mars - Diameter: 1,100 km
  7. Mare Tranquilitatis - Moon - Diameter: 870 km
  8. Argyre Planitia - Mars - Diameter: 800 km
  9. Mare Serenitatis - Moon - Diameter: 700 km
  10. Mare Nubium - Moon - Diameter: 700 km
  11. Beethoven - Mercury - Diameter: 625 km
  12. Valhalla - Callisto - Diameter: 600 km, with rings to 4,000 km diameter
  13. Hertzsprung - Moon - Diameter: 590 km
  14. Apollo - Moon - Diameter: 540 km
  15. Huygens - Mars - Diameter: 470 km
  16. Schiaparelli - Mars - Diameter: 470 km
  17. Menrva - Titan - Diameter: 440 km
  18. Korolev - Moon - Diameter: 430 km
  19. Dostievskij - Mercury - Diameter: 400 km
  20. Odysseus - Tethys - Diameter: 400 km
  21. Tolstoj - Mercury - Diameter: 390 km
  22. Goethe - Mercury - Diameter: 380 km
  23. Mare Orientale - Moon - Diameter: 350 km, with rings to 930 km diameter
  24. Epigeus - Ganymede - Diameter: 340 km
  25. Gertrude - Titania - Diameter: 320 km
  26. Asgard - Callisto - Diameter: 300 km, with rings to 1,400 km diameter
  27. Vredefort crater - Earth - Diameter: 300 km
  28. Mead - Venus - Diameter: 270 km

There are approximately twelve more impact craters/basins larger than 300 km on the Moon, five on Mercury, and four on Mars.[2] Large basins, some unnamed but mostly smaller than 300 km, can also be found on Saturn's moons Dione, Rhea and Iapetus. The South Pole-Aitken basin is an impact crater on Earths Moon. ... NASA image of Hellas Planitia Hellas Planitia, also known as the Hellas Impact Basin, is a roughly circular impact crater located in the southern hemisphere of the planet Mars. ... The Skinakas Basin is the informal name given to a structure on Mercury that appears to be an extremely large impact basin. ... The Caloris Basin, also called Caloris Planitia, is an impact crater, on Mercury, which is ~1350km in diameter. ... Oblique view of Mare Imbrium looking south towards Copernicus crater. ... Topography of Isidis Planitia Isidis Planitia is a plain located inside a giant impact basin on Mars. ... The Sea of Tranquility of the Moon. ... Argyre Planitia is a plain located in the Argyre impact basin in the southern highlands of Mars between -35 and -61 deg S and 27 and 62 deg W. The basin is approximately 1120 miles (1800 kilometers) wide, the second-largest impact basin on Mars after Hellas Planitia, and drops... A map of Mare Serenitatis. ... The Sea of Clouds of the Moon. ... Valhalla crater, on Callisto Valhalla is the largest impact crater on Jupiters moon Callisto. ... Hertzsprung is an enormous lunar crater that is located on the far side of the Moon, beyond the western limb. ... Apollo is an enormous impact crater located in the southern hemisphere on the far side of the Moon. ... Huygens is an impact crater on mars named in honour of the Dutch astronomer, mathematician and physicist Christiaan Huygens. ... Elevation map of Schiaparelli crater, as seen by Mars Global Surveyor. ... Korolev is a large lunar crater of the form commonly termed a walled-plain. ... Odysseus is the huge, shallow crater on the right Odysseus is the largest crater on Saturns moon Tethys. ... 1967 photograph made by NASAs Lunar Orbiter 4 Like a target ring bulls-eye, the lunar mare Mare Orientale (the eastern sea) is one of the most striking large scale lunar features. ... Categories: Stub | Craters on Jupiters moons ... Vredefort crater is the largest verified impact crater on Earth. ... Margaret Mead is honoured by the crater Mead on Venus. ...


See also

Satellite image of Santorini. ... Artists reconstruction of a major impact event. ... Artists impression of a major impact event. ... The physicist Sir Isaac Newton first developed this idea to get rough approximations for the impact depth for projectiles travelling at high velocities. ... Nemesis is a hypothetical red dwarf star or brown dwarf, orbiting the Sun at a distance of about 50,000 to 100,000 AU, somewhat beyond the Oort cloud. ... Rampart craters are a specific type of Martian impact crater which are accompanied by distinctive fluidized ejecta features. ... Crater ray system on the far side of the Moon. ...

References

  • Charles A. Wood and Leif Andersson, New Morphometric Data for Fresh Lunar Craters, 1978, Proceedings 9th Lunar and Planet. Sci. Conf.
  • Bond, J. W., "The development of central peaks in lunar craters", Moon and the Planets, vol. 25, Dec. 1981.
  • Melosh, H.J., 1989, Impact cratering: A geologic process: New York, Oxford University Press, 245 p.

External links

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  Results from FactBites:
 
Lunar Impact Crater Geology and Structure (1154 words)
Bessel Crater, 16 kilometers in diameter and 2 kilometers deep, is an example of a transitional crater between simple and complex craters.
Copernicus Crater, 93 kilometers in diameter, is one of the youngest and freshest impact craters on the nearside of the Moon.
Schrodinger is one of the youngest, freshest impact basins on the Moon.
NationMaster - Encyclopedia: Clavius (crater) (1112 words)
Scheiner is a lunar impact crater that lies to the west of the enormous Clavius walled-plain.
The crater floor retains a diminshed remnant of a central massif, which lies between Clavius C and N. The relative smoothness of the floor and the low size of the central peaks may indicate that the crater surface was formed some time after the original impact.
This is a well-known lunar impact crater 83km in diameter and lies on the eastern edge of the Mare Imbrium.
  More results at FactBites »

 
 

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