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Meteorites By Name
A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate energy. It then becomes a meteor and forms a fireball, also known as a shooting star; astronomers call the brightest examples " bolides". Once it settles on the larger body's surface, the meteor becomes a meteorite. Meteorites vary greatly in size. For geologists, a bolide is a meteorite large enough to create an impact crater. Meteorites that are recovered after being observed as they transit the atmosphere and impact the Earth are called meteorite falls. All others are known as meteorite finds. Meteorites have traditionally been divided into three broad categories: stony meteorites tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Namibie Hoba Meteorite 05
Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and east. Although it does not border Zimbabwe, less than 200 metres (660 feet) of the Botswanan right bank of the Zambezi River separates the two countries. Namibia gained independence from South Africa on 21 March 1990, following the Namibian War of Independence. Its capital and largest city is Windhoek. Namibia is a member state of the United Nations (UN), the Southern African Development Community (SADC), the African Union (AU) and the Commonwealth of Nations. The driest country in sub-Saharan Africa, Namibia has been inhabited since pre-historic times by the San, Damara and Nama people. Around the 14th century, immigrating Bantu peoples arrived as part of the Bantu expansion. Since then, the Bantu groups, the largest being the Ovambo, ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteorite Classification
In meteoritics, a meteorite classification system attempts to group similar meteorite, meteorites and allows scientists to communicate with a standardized terminology when discussing them. Meteorites are classified according to a variety of characteristics, especially mineralogy, mineralogical, petrology, petrological, chemistry, chemical, and isotope, isotopic properties. Terminology There is no single, standardized terminology used in meteorite classification; however, commonly used terms for categories include ''types'', ''classes'', ''clans'', ''groups'', and ''subgroups''. Some researchers hierarchize these terms, but there is no consensus as to which hierarchy is most appropriate. Meteorites that do not fit any known group (though they may fit somewhere within a higher level of classification) are ''ungrouped''. Genetic relationships Meteorite classification may indicate that a "genetic" relationship exists between similar meteorite specimens. Similarly classified meteorit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonic Boom
A sonic boom is a sound associated with shock waves created when an object travels through the air faster than the speed of sound. Sonic booms generate enormous amounts of sound energy, sounding similar to an explosion or a thunderclap to the human ear. A decibel is the primary unit measurement of sound. "A thunderclap is incredibly loud, producing levels between 100 and 120 dBA (Decibel, decibels A)- the equivalent of standing near a jet during take-off." The crack of a supersonic bullet passing overhead or the crack of a bullwhip are examples of a sonic boom in miniature. Sonic booms due to large supersonic aircraft can be particularly loud and startling, tend to awaken people, and may cause minor damage to some structures. This led to prohibition of routine supersonic flight overland. Although they cannot be completely prevented, research suggests that with careful shaping of the vehicle, the nuisance due to the sonic booms may be reduced to the point that overland super ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morokweng Impact Structure
The Morokweng impact structure is an impact structure buried beneath the Kalahari Desert near the town of Morokweng in South Africa's North West province, close to the border with Botswana. Description The impact structure is at least about in diameter and the age is estimated to be 146.06 ± 0.16 million years, placing it within the Tithonian stage of the Late Jurassic, several million years before the Jurassic–Cretaceous boundary.Kenny, G.G., Harrigan, C.O., Schmitz, M.D., Crowley, J.L., Wall, C.J., Andreoli, M.A., Gibson, R.L. and Maier, W.D., 2021. ''Timescales of impact melt sheet crystallization and the precise age of the Morokweng impact structure, South Africa''. ''Earth and Planetary Science Letters'', 567, no. 117013, 13 p.Schmieder, M. and Kring, D.A., 2020. ''Earth's impact events through geologic time: a list of recommended ages for terrestrial impact structures and deposits''. ''Astrobiology'', 20(1), pp.91-141. Discovered in 1994, it is not exposed at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunguska Event
The Tunguska event (occasionally also called the Tunguska incident) was an approximately 12-megaton explosion that occurred near the Podkamennaya Tunguska River in Yeniseysk Governorate (now Krasnoyarsk Krai), Russia, on the morning of June 30, 1908. The explosion over the sparsely populated Eastern Siberian Taiga flattened an estimated 80 million trees over an area of of forest, and eyewitness reports suggest that at least three people may have died in the event. The explosion is generally attributed to a meteor air burst: the atmospheric explosion of a stony asteroid about in size. The supposed asteroid approached from the east-southeast, and likely with a relatively high speed of about (~ Ma 80). It is classified as an impact event, even though no impact crater has been found; the object is thought to have disintegrated at an altitude of rather than having hit the surface of the Earth. The Tunguska event is the largest impact event on Earth in recorded history, thou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wabar Craters
The Wabar craters are impact craters located in Saudi Arabia first brought to the attention of Western scholars by British Arabist, explorer, writer and Colonial Office intelligence officer St John Philby, who discovered them while searching for the legendary city of Ubar in Arabia's Rub' al Khali ("Empty Quarter") in 1932. The expeditions 1932 Philby The vast desert wasteland of southern Saudi Arabia known as the Empty Quarter, or ''Rub' al Khali'' in Arabic, is one of the most desolate places on Earth. In 1932, Harry St John "Jack" Philby was hunting for a city named Ubar, that the Quran describes being destroyed by God for defying the Prophet Hud. Philby transliterated the name of the city as Wabar. Philby had heard of Bedouin legends of an area called ''Al Hadida'' ("place of iron" in Arabic) with ruins of ancient habitations, and also an area where a piece of iron the size of a camel had been found, and so organized an expedition to visit the site. After a month's jour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odessa Meteor Crater
The Odessa Meteor Crater is a meteorite crater in the southwestern part of Ector County, southwest of the city of Odessa of West Texas, United States. It is accessible approximately south of Interstate 20 at Exit 108 (Moss Road). This is one of three impact crater sites found in Texas, the others being the older and much larger Sierra Madera crater and the Marquez crater. The ''Handbook of Texas Online'' describes the Odessa meteor crater as the largest of several smaller craters in the immediate area that were formed by the impact of thousands of octahedrites (an iron metallic type) that fell in prehistoric times. The web site of the University of Texas of the Permian Basin (UTPB, Center for Energy and Economic Diversification), identifies five craters at the Odessa site and shows a distribution map of the meteorite fragments recovered from the area. The recoveries have generally come from an area to the north and northwest of the main crater site, with only a few found to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barringer Meteor Crater
Meteor Crater, or Barringer Crater, is a meteorite impact crater about east of Flagstaff and west of Winslow in the desert of northern Arizona, United States. The site had several earlier names, and fragments of the meteorite are officially called the Canyon Diablo Meteorite, after the adjacent Cañon Diablo. Because the United States Board on Geographic Names recognizes names of natural features derived from the nearest post office, the feature acquired the name of "Meteor Crater" from the nearby post office named Meteor. Meteor Crater lies at an elevation of above sea level. It is about in diameter, some deep, and is surrounded by a rim that rises above the surrounding plains. The center of the crater is filled with of rubble lying above crater bedrock. One of the interesting features of the crater is its squared-off outline, believed to be caused by existing regional jointing (cracks) in the strata at the impact site. Despite historic attempts to make the crater ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypervelocity
Hypervelocity is very high velocity, approximately over 3,000 meters per second (6,700 mph, 11,000 km/h, 10,000 ft/s, or Mach 8.8). In particular, hypervelocity is velocity so high that the strength of materials upon impact is very small compared to inertial stresses. Thus, metals and fluids behave alike under hypervelocity impact. Extreme hypervelocity results in vaporization of the impactor and target. For structural metals, hypervelocity is generally considered to be over 2,500 m/s (5,600 mph, 9,000 km/h, 8,200 ft/s, or Mach 7.3). Meteorite craters are also examples of hypervelocity impacts. Overview The term "hypervelocity" refers to velocities in the range from a few kilometers per second to some tens of kilometers per second. This is especially relevant in the field of space exploration and military use of space, where hypervelocity impacts (e.g. by space debris or an attacking projectile) can result in anything from minor component ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escape Velocity
In celestial mechanics, escape velocity or escape speed is the minimum speed needed for a free, non- propelled object to escape from the gravitational influence of a primary body, thus reaching an infinite distance from it. It is typically stated as an ideal speed, ignoring atmospheric friction. Although the term "escape velocity" is common, it is more accurately described as a speed than a velocity because it is independent of direction; the escape speed increases with the mass of the primary body and decreases with the distance from the primary body. The escape speed thus depends on how far the object has already traveled, and its calculation at a given distance takes into account that without new acceleration it will slow down as it travels—due to the massive body's gravity—but it will never quite slow to a stop. A rocket, continuously accelerated by its exhaust, can escape without ever reaching escape speed, since it continues to add kinetic energy from its engine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Novato Meteorite Impact Pit
Novato (Spanish for "Novatus") is a city in Marin County, California, in the North Bay region of the Bay Area. At the 2020 census, Novato had a population of 53,225. History What is now Novato was originally the site of several Coast Miwok villages: Chokecherry, near downtown Novato; Puyuku, near Ignacio; and Olómpali, at the present-day Olompali State Historic Park. Mexican era In 1839, the Mexican government granted the Rancho Novato to Fernando Feliz. The rancho was named after a local Miwok leader who had probably been given the name of Saint Novatus at his baptism. Subsequently, four additional land grants were made in the area: Rancho Corte Madera de Novato, to John Martin in 1839; Rancho San Jose, to Ignacio Pacheco in 1840; Rancho Olómpali, awarded in 1843 to Camilo Ynitia, son of a Coast Miwok chief; and Rancho Nicasio, by far the largest at , awarded to Pablo de la Guerra and John B.R. Cooper in 1844. Post-Conquest era Following the American Conquest of C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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