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A meteorite is a rock that originated in outer space and has fallen to 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 event are called . All others are known as . Meteorites have traditionally been divided into three broad categories: stony meteorites that are rocks, mainly composed of ; that are largely composed of ferronickel; and stony-iron meteorites that contain large amounts of both metallic and rocky material. Modern classification schemes divide meteorites into groups according to their structure, chemical and isotopic composition and mineralogy. "Meteorites" less than ~ in diameter are classified as , however micrometeorites differ from meteorites in that they typically melt completely in the atmosphere and fall to Earth as quenched droplets. Extraterrestrial meteorites have been found on the Moon and on Mars.
Most space rocks crashing into Earth come from a single source. The origin of most meteorites can be traced to just a handful of asteroid breakup events – and possibly even individual . New research shows most space rocks crashing into Earth come from a single source
Large meteoroids may strike the earth with a significant fraction of their escape velocity (second cosmic velocity), leaving behind a hypervelocity impact crater. The kind of crater will depend on the size, composition, degree of fragmentation, and incoming angle of the impactor. The force of such collisions has the potential to cause widespread destruction. Make your own impact at the University of Arizona . Lpl.arizona.edu. Retrieved on 17 December 2011. The most frequent hypervelocity cratering events on the Earth are caused by iron meteoroids, which are most easily able to transit the atmosphere intact. Examples of craters caused by iron meteoroids include Barringer Meteor Crater, Odessa Meteor Crater, Wabar craters, and Wolfe Creek crater; iron meteorites are found in association with all of these craters. In contrast, even relatively large stony or icy bodies such as small or , up to millions of tons, are disrupted in the atmosphere, and do not make impact craters. Although such disruption events are uncommon, they can cause a considerable concussion to occur; the famed Tunguska event probably resulted from such an incident. Very large stony objects, hundreds of meters in diameter or more, weighing tens of millions of or more, can reach the surface and cause large craters but are very rare. Such events are generally so energetic that the impactor is completely destroyed, leaving no meteorites. (The first example of a stony meteorite found in association with a large impact crater, the Morokweng impact structure in South Africa, was reported in May 2006.)
Several phenomena are well documented during witnessed meteorite falls too small to produce hypervelocity craters. (1978). 9780852743744, Oxford Univ. Press. ISBN 9780852743744 The fireball that occurs as the meteoroid passes through the atmosphere can appear to be very bright, rivaling the sun in intensity, although most are far dimmer and may not even be noticed during the daytime. Various colors have been reported, including yellow, green, and red. Flashes and bursts of light can occur as the object breaks up. Explosions, detonations, and rumblings are often heard during meteorite falls, which can be caused by as well as resulting from major fragmentation events. These sounds can be heard over wide areas, with a radius of a hundred or more kilometers. Whistling and hissing sounds are also sometimes heard but are poorly understood. Following the passage of the fireball, it is not unusual for a dust trail to linger in the atmosphere for several minutes.
As meteoroids are heated during atmospheric entry, their surfaces melt and experience ablation. They can be sculpted into various shapes during this process, sometimes resulting in shallow thumbprint-like indentations on their surfaces called . If the meteoroid maintains a fixed orientation for some time, without tumbling, it may develop a conical "nose cone" or "heat shield" shape. As it decelerates, eventually the molten surface layer solidifies into a thin fusion crust, which on most meteorites is black (on some , the fusion crust may be very light-colored). On stony meteorites, the heat-affected zone is at most a few mm deep; in iron meteorites, which are more thermally conductive, the structure of the metal may be affected by heat up to below the surface. Reports vary; some meteorites are reported to be "burning hot to the touch" upon landing, while others are alleged to have been cold enough to condense water and form a frost. Fall of the Muzaffarpur iron meteorite . Lpi.usra.edu (11 April 1964). Retrieved on 17 December 2011. Fall of the Menziswyl stone . Lpi.usra.edu (29 July 2006). Retrieved on 17 December 2011. The Temperature of Meteorites . articles.adsabs.harvard.edu (February 1934). Retrieved on 28 May 2014.
Meteoroids that disintegrate in the atmosphere may fall as meteorite showers, which can range from only a few up to thousands of separate individuals. The area over which a meteorite shower falls is known as its strewn field. Strewn fields are commonly ellipse in shape, with the major axis parallel to the direction of flight. In most cases, the largest meteorites in a shower are found farthest down-range in the strewn field.
About 86% of the meteorites are chondrites, Meteoritical Bulletin Database . Lpi.usra.edu (1 January 2011). Retrieved on 17 December 2011. The NHM Catalogue of Meteorites . Internt.nhm.ac.uk. Retrieved on 17 December 2011. MetBase . Metbase.de. Retrieved on 17 December 2011. which are named for the small, round particles they contain. These particles, or , are composed mostly of silicate minerals that appear to have been melted while they were free-floating objects in space. Certain types of chondrites also contain small amounts of Organic material, including , and presolar grains. Chondrites are typically about 4.55 billion years old and are thought to represent material from the asteroid belt that never coalesced into large bodies. Like , chondritic asteroids are some of the oldest and most primitive materials in the Solar System. Chondrites are often considered to be "the building blocks of the planets".
About 8% of the meteorites are (meaning they do not contain chondrules), some of which are similar to terrestrial . Most achondrites are also ancient rocks, and are thought to represent crustal material of differentiated planetesimals. One large family of achondrites (the ) may have originated on the parent body of the Vesta family, although this claim is disputed. Others derive from unidentified asteroids. Two small groups of achondrites are special, as they are younger and do not appear to come from the asteroid belt. One of these groups comes from the Moon, and includes rocks similar to those brought back to Earth by Apollo program and Luna programme programs. The other group is almost certainly from Mars and constitutes the only materials from other planets ever recovered by humans.
About 5% of meteorites that have been seen to fall are composed of iron-nickel , such as kamacite and/or taenite. Most iron meteorites are thought to come from the cores of planetesimals that were once molten. As with the Earth, the denser metal separated from silicate material and sank toward the center of the planetesimal, forming its core. After the planetesimal solidified, it broke up in a collision with another planetesimal. Due to the low abundance of iron meteorites in collection areas such as Antarctica, where most of the meteoric material that has fallen can be recovered, it is possible that the percentage of iron-meteorite falls is lower than 5%. This would be explained by a recovery bias; laypeople are more likely to notice and recover solid masses of metal than most other meteorite types. The abundance of iron meteorites relative to total Antarctic finds is 0.4%.
Stony-iron meteorites constitute the remaining 1%. They are a mixture of iron-nickel metal and silicate minerals. One type, called , is thought to have originated in the boundary zone above the core regions where iron meteorites originated. The other major type of stony-iron meteorites is the .
Tektites (from Greek tektos, molten) are not themselves meteorites, but are rather natural glass objects up to a few centimeters in size that were formed—according to most scientists—by the impacts of large meteorites on Earth's surface. A few researchers have favored tektites originating from the Moon as volcanic ejecta, but this theory has lost much of its support over the last few decades.
Over at least the range from to roughly , the rate at which Earth receives meteors obeys a power law distribution as follows:
where N (> D) is the expected number of objects larger than a diameter of D meters to hit Earth in a year. This is based on observations of bright meteors seen from the ground and space, combined with surveys of near-Earth asteroids. Above in diameter, the predicted rate is somewhat higher, with a asteroid (one teraton TNT equivalent) every couple of million yearsabout 10 times as often as the power-law extrapolation would predict.
In 2018, researchers found that 4.5 billion-year-old meteorites found on Earth contained liquid water along with prebiotic complex organic substances that may be ingredients for life.
In 2019, scientists reported detecting sugar molecules in meteorites for the first time, including ribose, suggesting that chemical processes on can produce some organic compounds fundamental to life, and supporting the notion of an RNA world prior to a DNA-based Abiogenesis on Earth.
In 2022, a Japanese group reported that they had found adenine (A), thymine (T), guanine (G), cytosine (C) and uracil (U) inside carbon-rich meteorites. These compounds are building blocks of DNA and RNA, the genetic code of all life on Earth. These compounds have also occurred spontaneously in laboratory settings emulating conditions in outer space. "These meteorites contain all of the building blocks of DNA" , LiveScience, 28 April 2022
The most commonly employed weathering scale, used for ordinary chondrites, ranges from W0 (pristine state) to W6 (heavy alteration).
A small number of meteorite falls have been observed with automated cameras and recovered following calculation of the impact point. The first of these was the Příbram meteorite, which fell in Czechoslovakia (now the Czech Republic) in 1959. In this case, two cameras used to photograph meteors captured images of the fireball. The images were used both to determine the location of the stones on the ground and, more significantly, to calculate for the first time an accurate orbit for a recovered meteorite.
Following the Příbram fall, other nations established automated observing programs aimed at studying infalling meteorites. One of these was the Prairie Network, operated by the Smithsonian Astrophysical Observatory from 1963 to 1975 in the midwestern US. This program also observed a meteorite fall, the Lost City chondrite, allowing its recovery and a calculation of its orbit. Another program in Canada, the Meteorite Observation and Recovery Project, ran from 1971 to 1985. It too recovered a single meteorite, Innisfree, in 1977. Finally, observations by the European Fireball Network, a descendant of the original Czech program that recovered Příbram, led to the discovery and orbit calculations for the Neuschwanstein meteorite in 2002. NASA has an automated system that detects meteors and calculates the orbit, magnitude, ground track, and other parameters over the southeast USA, which often detects a number of events each night.
In the late 1960s, Roosevelt County, New Mexico was found to be a particularly good place to find meteorites. After the discovery of a few meteorites in 1967, a public awareness campaign resulted in the finding of nearly 100 new specimens in the next few years, with many being by a single person, Ivan Wilson. In total, nearly 140 meteorites were found in the region since 1967. In the area of the finds, the ground was originally covered by a shallow, loose soil sitting atop a hardpan layer. During the dustbowl era, the loose soil was blown off, leaving any rocks and meteorites that were present stranded on the exposed surface.
Beginning in the mid-1960s, amateur meteorite hunters began scouring the arid areas of the southwestern United States. A Preliminary Report on the Lucerne Valley, San County, California, Aerolites Retrieved on 8 March 2018. To date, thousands of meteorites have been recovered from the Mojave Desert, Sonoran Desert, Great Basin, and Chihuahuan Deserts, with many being recovered on dry lake beds. Significant finds include the three-tonne Old Woman meteorite, currently on display at the Desert Discovery Center in Barstow, California, and the Franconia and Gold Basin meteorite strewn fields; hundreds of kilograms of meteorites have been recovered from each. Meteoritical Bulletin entry for Franconia . Lpi.usra.edu. Retrieved on 8 January 2020. Meteoritical Bulletin entry for Gold Basin . Lpi.usra.edu. Retrieved on 8 January 2020. Found Locally in Arizona: Collisional Remnants of Planetesimal Affected by Impacts During the First Billion Years of Solar System History . Bombardment: Shaping Planetary Surfaces and Their Environments 2018 (LPI Contrib. No. 2107). 30 September 2018. Retrieved on 5 February 2020. A number of finds from the American Southwest have been submitted with false find locations, as many finders think it is unwise to publicly share that information for fear of confiscation by the federal government and competition with other hunters at published find sites. Old Woman Meteorite. discoverytrails.org Meteoritical Bulletin entry for Los Angeles meteorite . Lpi.usra.edu (27 May 2009). Retrieved on 8 January 2020. The Meteorite List Archives . meteorite-list-archives.com (24 August 2011). Retrieved on 5 February 2020. Several of the meteorites found recently are currently on display in the Griffith Observatory in Los Angeles, and at UCLA's Meteorite Gallery. The UCLA Meteorite Collection. ucla.edu
Shortly thereafter, the United States began its own program to search for Antarctic meteorites, operating along the Transantarctic Mountains on the other side of the continent: the Antarctic Search for Meteorites (ANSMET) program. (2025). 9780521258722, Cambridge University Press. ISBN 9780521258722 European teams, starting with a consortium called "EUROMET" in the 1990/91 season, and continuing with a program by the Italian Programma Nazionale di Ricerche in Antartide have also conducted systematic searches for Antarctic meteorites.
The Antarctic Scientific Exploration of China has conducted successful meteorite searches since 2000. A Korean program (KOREAMET) was launched in 2007 and has collected a few meteorites. The combined efforts of all of these expeditions have produced more than 23,000 classified meteorite specimens since 1974, with thousands more that have not yet been classified. For more information see the article by Harvey (2003).
Although meteorites had been sold commercially and collected by hobbyists for many decades, up to the time of the Saharan finds of the late 1980s and early 1990s, most meteorites were deposited in or purchased by museums and similar institutions where they were exhibited and made available for scientific research. The sudden availability of large numbers of meteorites that could be found with relative ease in places that were readily accessible (especially compared to Antarctica), led to a rapid rise in commercial collection of meteorites. This process was accelerated when, in 1997, meteorites coming from both the Moon and Mars were found in Libya. By the late 1990s, private meteorite-collecting expeditions had been launched throughout the Sahara. Specimens of the meteorites recovered in this way are still deposited in research collections, but most of the material is sold to private collectors. These expeditions have now brought the total number of well-described meteorites found in Algeria and Libya to more than 500.Meteoritical Bulletin Database www.lpi.usra.edu
The recovery of meteorites from Oman is currently prohibited by national law, but a number of international hunters continue to remove specimens now deemed national treasures. This new law provoked a small international incident, as its implementation preceded any public notification of such a law, resulting in the prolonged imprisonment of a large group of meteorite hunters, primarily from Russia, but whose party also consisted of members from the US as well as several other European countries.
Meteorite falls may have been the source of cultish worship. The cult in the Temple of Artemis at Ephesus, one of the Seven Wonders of the Ancient World, possibly originated with the observation and recovery of a meteorite that was understood by contemporaries to have fallen to the earth from Jupiter, the principal Roman deity."And when the townclerk had appeased the people, he said, Ye men of Ephesus, what man is there that knoweth not how that the city of the Ephesians is a worshipper of the great goddess Diana, and of the image which fell down from Jupiter?" There are reports that a sacred stone was enshrined at the temple that may have been a meteorite.
The Black Stone set into the wall of the Kaaba has often been presumed to be a meteorite, but the little available evidence for this is inconclusive. New Light on the Origin of the Holy Black Stone of the Ka'ba . Author: Thomsen, E. Journal: Meteoritics, vol. 15, no. 1, p. 87 (2025). 9780521663038, Cambridge University Press. ISBN 9780521663038
Some Native Americans treated meteorites as ceremonial objects. In 1915, a iron meteorite was found in a Sinagua (c. 1100–1200 AD) burial cyst near Camp Verde, Arizona, respectfully wrapped in a feather cloth.H. H. Nininger, 1972, Find a Falling Star (autobiography), New York, Paul S. Erikson. A small pallasite was found in a pottery jar in an old burial found at Pojoaque Pueblo, New Mexico. Nininger reports several other such instances, in the Southwest US and elsewhere, such as the discovery of Native American beads of meteoric iron found in Hopewell Tumulus, and the discovery of the Winona meteorite in a Native American stone-walled crypt.A. L. Christenson, J. W. Simmons' Account of the Discovery of the Winona Meteorite. Meteorite 10(3):14–16, 2004
Two of the oldest recorded meteorite falls in Europe are the Elbogen (1400) and Ensisheim (1492) meteorites. The German physicist, Ernst Florens Chladni, was the first to publish (in 1794) the idea that meteorites might be rocks that originated not from Earth, but from space. His booklet was "On the Origin of the Iron Masses Found by Pallas and Others Similar to it, and on Some Associated Natural Phenomena".Chladni, Ernst Florens Friedrich, Über den Ursprung der von Pallas gefundenen und anderer ihr ähnlicher Eisenmassen und über einige damit in Verbindung stehende Naturerscheinungen On (Riga, Latvia: Johann Friedrich Hartknoch, 1794). Available on-line at: Saxon State and University Library at Dresden, Germany . In this he compiled all available data on several meteorite finds and falls concluded that they must have their origins in outer space. The scientific community of the time responded with resistance and mockery. It took nearly ten years before a general acceptance of the origin of meteorites was achieved through the work of the French scientist Jean-Baptiste Biot and the British chemist, Edward Howard.Edward Howard, John Lloyd Williams, and Count de Bournon (1802) "Experiments and observations on certain stony and metalline substances, which at different times are said to have fallen on the earth; also on various kinds of native iron," Philosophical Transactions of the Royal Society of London, 92 : 168–212. Available on-line at: Royal Society Biot's study, initiated by the French Academy of Sciences, was compelled by a fall of thousands of meteorites on 26 April 1803 from the skies of L'Aigle, France.J.B. Biot (1803) Relation d'un voyage fait dans le département de l'Orne, pour constater la réalité d'un météore observé à l'Aigle le 26 floréal an 11 (Account of a journey made in the department of the Orne River, in order to ascertain the reality of a meteor observed in l'Aigle on the 26th of Floréal in the year 11) Note: The date "26 floréal" on the title page is a typographical error; the meteor shower actually occurred on 6 floréal (i.e., 26 April 1803) and everywhere else in the text the date "6 floréal" is given as the date of the meteor shower. (Paris, France: Baudouin, 1803).
Modern reports of meteorite strikes include:
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