Meteorite

Meteorite

Overview

A meteorite is a natural object originating in outer space
Outer space
Outer space is the void that exists between celestial bodies, including the Earth. It is not completely empty, but consists of a hard vacuum containing a low density of particles: predominantly a plasma of hydrogen and helium, as well as electromagnetic radiation, magnetic fields, and neutrinos....

 that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical object
Astronomical object
Astronomical objects or celestial objects are naturally occurring physical entities, associations or structures that current science has demonstrated to exist in the observable universe. The term astronomical object is sometimes used interchangeably with astronomical body...

s called meteoroid
Meteoroid
A meteoroid is a sand- to boulder-sized particle of debris in the Solar System. The visible path of a meteoroid that enters Earth's atmosphere is called a meteor, or colloquially a shooting star or falling star. If a meteoroid reaches the ground and survives impact, then it is called a meteorite...

s, but they are also sometimes produced by impacts of asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

s. When a meteoroid enters the atmosphere, ram pressure
Ram pressure
In physics, ram pressure is a pressure exerted on a body which is moving through a fluid medium. It causes a strong drag force to be exerted on the body. It is given by:P= \rho v^2...

 (not friction
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and/or material elements sliding against each other. There are several types of friction:...

) causes the body to heat up and emit light, thus forming a fireball, also known as a meteor or shooting/falling star.
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Timeline

1492   The Ensisheim Meteorite, the oldest meteorite with a known date of impact, strikes the earth around noon in a wheat field outside the village of Ensisheim, Alsace, France.

1804   High Possil Meteorite: The first recorded meteorite in Scotland falls in Possil.

1846   The Cape Girardeau meteorite, a 2.3 kg chondrite-type meteorite strikes near the town of Cape Girardeau in Cape Girardeau County, Missouri.

1861   The Canellas meteorite, an 859-gram chondrite-type meteorite, strikes the earth near Barcelona, Spain.

1881   A meteorite lands near the village of Grossliebenthal, southwest of Odessa, Ukraine.

1911   A 772 gram stony meteorite strikes the earth near Kilbourn, Columbia County, Wisconsin damaging a barn.

1912   A meteorite with an estimated mass of 190 kg explodes over the town of Holbrook in Navajo County, Arizona causing approximately 16,000 pieces of debris to rain down on the town.

1916   A 611 gram chondrite type meteorite strikes a house near the village of Baxter in Stone County, Missouri.

1932   A {{convert|5.1|kg|lb}} chondrite-type meteorite breaks into at least seven pieces and lands near the town of Archie in Cass County, Missouri.

1973   The Cañon City meteorite, a 1.4 kg chondrite type meteorite, strikes in Fremont County, Colorado.

 
Encyclopedia

A meteorite is a natural object originating in outer space
Outer space
Outer space is the void that exists between celestial bodies, including the Earth. It is not completely empty, but consists of a hard vacuum containing a low density of particles: predominantly a plasma of hydrogen and helium, as well as electromagnetic radiation, magnetic fields, and neutrinos....

 that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical object
Astronomical object
Astronomical objects or celestial objects are naturally occurring physical entities, associations or structures that current science has demonstrated to exist in the observable universe. The term astronomical object is sometimes used interchangeably with astronomical body...

s called meteoroid
Meteoroid
A meteoroid is a sand- to boulder-sized particle of debris in the Solar System. The visible path of a meteoroid that enters Earth's atmosphere is called a meteor, or colloquially a shooting star or falling star. If a meteoroid reaches the ground and survives impact, then it is called a meteorite...

s, but they are also sometimes produced by impacts of asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

s. When a meteoroid enters the atmosphere, ram pressure
Ram pressure
In physics, ram pressure is a pressure exerted on a body which is moving through a fluid medium. It causes a strong drag force to be exerted on the body. It is given by:P= \rho v^2...

 (not friction
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and/or material elements sliding against each other. There are several types of friction:...

) causes the body to heat up and emit light, thus forming a fireball, also known as a meteor or shooting/falling star. The term bolide refers to either an extraterrestrial body that collides with the Earth, or to an exceptionally bright, fireball-like meteor regardless of whether it ultimately impacts the surface.

More generally, a meteorite on the surface of any celestial body is a natural object that has come from elsewhere in space. Meteorites have been found on the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 and Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

.

Meteorites that are recovered after being observed as they transited the atmosphere or impacted the Earth are called falls. All other meteorites are known as finds. As of February 2010, there are approximately 1,086 witnessed falls
Meteorite falls
Meteorite falls, also called observed falls, are those meteorites that were witnessed by people or automated devices as they moved through the atmosphere or hit the Earth, and were subsequently collected. All other meteorites are called "finds"...

 having specimens in the world's collections. In contrast, there are over 38,660 well-documented meteorite finds.

Meteorites have traditionally been divided into three broad categories: stony meteorites are rocks, mainly composed of silicate minerals
Silicate minerals
The silicate minerals make up the largest and most important class of rock-forming minerals, constituting approximately 90 percent of the crust of the Earth. They are classified based on the structure of their silicate group...

; iron meteorite
Iron meteorite
Iron meteorites are meteorites that consist overwhelmingly of nickel-iron alloys. The metal taken from these meteorites is known as meteoric iron and was one of the earliest sources of usable iron available to humans.-Occurrence:...

s are largely composed of metallic iron-nickel; and, stony-iron meteorites 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.

Naming


Meteorites are always named for the place where they were found, usually a nearby town or geographic feature. In cases where many meteorites were found in one place, the name may be followed by a number or letter (e.g., Allan Hills 84001 or Dimmitt (b)). Some meteorites have informal nicknames: the Sylacauga
Sylacauga, Alabama
Sylacauga is a city in Talladega County, Alabama, United States. At the 2000 census the population was 12,616.Nicknames for Sylacauga include: "The Marble City," "Buzzard's Roost" and "Sly Town"....

 meteorite is sometimes called the "Hodges meteorite" after Ann Hodges, the woman who was struck by it; the Canyon Diablo meteorite
Canyon Diablo meteorite
The Canyon Diablo meteorite comprises many fragments of the asteroid that impacted at Barringer Crater , Arizona, USA. Meteorites have been found around the crater rim, and are named for nearby Canyon Diablo, which lies about three to four miles west of the crater.-History:The asteroid fell about...

, which formed Meteor Crater
Meteor Crater
Meteor Crater is a meteorite impact crater located approximately east of Flagstaff, near Winslow in the northern Arizona desert of the United States. Because the US Department of the Interior Division of Names commonly recognizes names of natural features derived from the nearest post office, the...

 has dozens of these aliases. However, the single, official name designated by the Meteoritical Society
Meteoritical Society
The Meteoritical Society is a non-profit scholarly organization founded in 1933 to promote research and education in planetary science with emphasis on studies of meteorites and other extraterrestrial materials that further our understanding of the origin and history of the solar system.The...

 is used by scientists, catalogers, and most collectors.

Fall phenomena




Most meteoroids disintegrate when entering Earth's atmosphere. However, an estimated 500 meteorites ranging in size from marble
Marble
Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite.Geologists use the term "marble" to refer to metamorphosed limestone; however stonemasons use the term more broadly to encompass unmetamorphosed limestone.Marble is commonly used for...

s to basketball
Basketball
Basketball is a team sport in which two teams of five players try to score points by throwing or "shooting" a ball through the top of a basketball hoop while following a set of rules...

s or larger do reach the surface each year; only 5 or 6 of these are typically recovered and made known to scientists. Few meteorites are large enough to create large impact crater
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 a larger body...

s. Instead, they typically arrive at the surface at their terminal velocity
Terminal velocity
In fluid dynamics an object is moving at its terminal velocity if its speed is constant due to the restraining force exerted by the fluid through which it is moving....

 and, at most, create a small pit. Even so, falling meteorites have reportedly caused damage to property, and injuries to livestock and people.
Large meteoroids may strike the ground with a significant fraction of their cosmic velocity, leaving behind a hypervelocity
Hypervelocity
The term hypervelocity usually refers to a very high velocity, approximately over 3,000 meters per second . In particular, it refers to velocities so high that the strength of materials upon impact is very small compared to inertial stresses. Thus, even metals behave like fluids under 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. 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
Odessa Meteor Crater
The Odessa Meteor Crater is a meteorite crater in the southwestern part of Ector County, southwest of the city of Odessa, Texas, United States. It is located approximately 3 miles south of I-20 at FM 1936 south...

, Wabar craters
Wabar craters
The Wabar craters are impact craters brought to the attention of Western scholars by an explorer searching for the legendary city of Ubar in Arabia.-1932 Philby:...

, and Wolfe Creek crater
Wolfe Creek crater
Wolfe Creek Crater is a well-preserved meteorite impact crater in Western Australia., It is accessed via the Tanami Road south of the town of Halls Creek...

; iron meteorites are found in association with all of these craters. In contrast, even relatively large stony or icy bodies like small comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...

s or asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

s, 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
Tunguska event
The Tunguska event, or Tunguska blast or Tunguska explosion, was an enormously powerful explosion that occurred near the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia, at about 7:14 a.m...

 probably resulted from such an incident. Very large stony objects, hundreds of meters in diameter or more, weighing tens of millions of ton
Ton
The ton is a unit of measure. It has a long history and has acquired a number of meanings and uses over the years. It is used principally as a unit of weight, and as a unit of volume. It can also be used as a measure of energy, for truck classification, or as a colloquial term.It is derived from...

s 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 very first example of a stony meteorite found in association with a large impact crater, the Morokweng crater
Morokweng crater
The Morokweng crater is an impact crater buried beneath the Kalahari Desert near the town of Morokweng in the Northwest Province of South Africa, close to the border with Botswana....

 in South Africa, was reported in May 2006.)
Several phenomena are well documented during witnessed meteorite falls too small to produce hypervelocity craters. 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 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 sonic boom
Sonic boom
A sonic boom is the sound associated with the shock waves created by an object traveling through the air faster than the speed of sound. Sonic booms generate enormous amounts of sound energy, sounding much like an explosion...

s as well as shock wave
Shock wave
A shock wave is a type of propagating disturbance. Like an ordinary wave, it carries energy and can propagate through a medium or in some cases in the absence of a material medium, through a field such as the electromagnetic field...

s resulting from major fragmentation events. These sounds can be heard over wide areas, up to many thousands of square km. Whistling and hissing sounds are also sometimes heard, but are poorly understood. Following passage of the fireball, it is not unusual for a dust trail to linger in the atmosphere for some time.

As meteoroids are heated during atmospheric entry, their surfaces melt and experience ablation
Ablation
Ablation is removal of material from the surface of an object by vaporization, chipping, or other erosive processes. This occurs in spaceflight during ascent and atmospheric reentry, glaciology, medicine, and passive fire protection.-Spaceflight:...

. They can be sculpted into various shapes during this process, sometimes resulting in deep "thumb-print" like indentations on their surfaces called regmaglypts. 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
Surface layer
The surface layer is the layer of a turbulent fluid most affected by interaction with a solid surface or the surface separating a gas and a liquid where the characteristics of the turbulence depend on distance from the interface...

 solidifies into a thin fusion crust, which on most meteorites is black (on some achondrites, the fusion crust may be very light colored). On stony meteorites, the heat-affected zone
Heat-affected zone
The heat-affected zone is the area of base material, either a metal or a thermoplastic, which has had its microstructure and properties altered by welding or heat intensive cutting operations. The heat from the welding process and subsequent re-cooling causes this change in the area surrounding...

 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 1 cm below the surface. Meteorites are sometimes reported to be warm to the touch when they land, but they are never hot. Reports, however, vary greatly, with some meteorites being reported as "burning hot to the touch" upon landing, and others forming a frost upon their surface.

Meteoroids that experience disruption 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 elliptical
Ellipse
In geometry, an ellipse is a plane curve that results from the intersection of a cone by a plane in a way that produces a closed curve. Circles are special cases of ellipses, obtained when the cutting plane is orthogonal to the cone's axis...

 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.

Meteorite types



Most meteorites are stony meteorites, classed as chondrite
Chondrite
Chondrites are stony meteorites that have not been modified due to melting or differentiation of the parent body. They formed when various types of dust and small grains that were present in the early solar system accreted to form primitive asteroids...

s and achondrite
Achondrite
An achondrite is a stony meteorite that does not contain chondrules. It consists of material similar to terrestrial basalts or plutonic rocks and has been differentiated and reprocessed to a lesser or greater degree due to melting and recrystallization on or within meteorite parent bodies...

s. Only 6% of meteorites are iron meteorite
Iron meteorite
Iron meteorites are meteorites that consist overwhelmingly of nickel-iron alloys. The metal taken from these meteorites is known as meteoric iron and was one of the earliest sources of usable iron available to humans.-Occurrence:...

s or a blend of rock and metal, the stony-iron meteorite
Pallasite
A pallasite is a type of stony–iron meteorite.-Structure and composition:It consists of cm-sized olivine crystals of peridot quality in an iron-nickel matrix. Coarser metal areas develop Widmanstätten patterns upon etching...

s. Modern classification of meteorites is complex, the review paper of Krot et al. (2007) summarizes modern meteorite taxonomy.

About 86% of the meteorites that fall on Earth are chondrite
Chondrite
Chondrites are stony meteorites that have not been modified due to melting or differentiation of the parent body. They formed when various types of dust and small grains that were present in the early solar system accreted to form primitive asteroids...

s, which are named for the small, round particles they contain. These particles, or chondrule
Chondrule
Chondrules are round grains found in chondrites. Chondrules form as molten or partially molten droplets in space before being accreted to their parent asteroids...

s, 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 matter, including amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...

s, and presolar grains
Presolar grains
Presolar grains are isotopically-distinct clusters of material found in the fine-grained matrix of primitive meteorites, such as chondrites, whose differences from the surrounding meteorite suggest that they are older than the solar system...

. Chondrites are typically about 4.55 billion years old and are thought to represent material from the asteroid belt
Asteroid belt
The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets...

 that never formed into large bodies. Like comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...

s, 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 that fall on Earth are achondrite
Achondrite
An achondrite is a stony meteorite that does not contain chondrules. It consists of material similar to terrestrial basalts or plutonic rocks and has been differentiated and reprocessed to a lesser or greater degree due to melting and recrystallization on or within meteorite parent bodies...

s (meaning they do not contain chondrules), some of which are similar to terrestrial mafic igneous rock
Igneous rock
Igneous rock is one of the three main rock types, the others being sedimentary and metamorphic rock. Igneous rock is formed through the cooling and solidification of magma or lava...

s. Most achondrites are also ancient rocks, and are thought to represent crustal material of asteroids. One large family of achondrites (the HED meteorite
HED meteorite
HED meteorites are a subgroup of achondrite meteorites. HED stands for "Howardite–Eucrite–Diogenite".These achondrites came from a differentiated parent body and experienced extensive igneous processing not much different from the magmatic rocks found on Earth and for this reason they closely...

s) may have originated on the asteroid 4 Vesta
4 Vesta
Vesta, formally designated 4 Vesta, is one of the largest asteroids, with a mean diameter of about . It was discovered by Heinrich Wilhelm Olbers on March 29, 1807, and is named after the Roman virgin goddess of home and hearth, Vesta....

. Others derive from different 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 and Luna
Luna programme
The Luna programme , occasionally called Lunik or Lunnik, was a series of robotic spacecraft missions sent to the Moon by the Soviet Union between 1959 and 1976. Fifteen were successful, each designed as either an orbiter or lander, and accomplished many firsts in space exploration...

 programs. The other group is almost certainly from Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

 and are the only materials from other planets ever recovered by man.

About 5% of meteorites that fall are iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...

 meteorites with intergrowths of iron-nickel
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...

 alloy
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...

s, such as kamacite
Kamacite
Kamacite is a mineral. It is an alloy of iron and nickel, usually in the proportions of 90:10 to 95:5 although impurities such as cobalt or carbon may be present. On the surface of Earth, it occurs naturally only in meteorites. It has a metallic luster, is gray and has no clear cleavage although...

 and taenite
Taenite
Taenite is a mineral found naturally on Earth mostly in iron meteorites. It is an alloy of iron and nickel, with nickel proportions of 20% up to 65%.The name is derived from the Greek for "band". Taenite is a major constituent of iron meteorites...

. Most iron meteorites are thought to come from the core of a number of asteroids that were once molten. As on Earth, the denser metal separated from silicate material and sank toward the center of the asteroid, forming a core. After the asteroid solidified, it broke up in a collision with another asteroid. Due to the low abundance of irons in collection areas such as Antarctica, where most of the meteoric material that has fallen can be recovered, it is possible that the actual percentage of iron-meteorite falls is lower than 5%.

Stony-iron meteorites constitute the remaining 1%. They are a mixture of iron-nickel metal and silicate
Silicate
A silicate is a compound containing a silicon bearing anion. The great majority of silicates are oxides, but hexafluorosilicate and other anions are also included. This article focuses mainly on the Si-O anions. Silicates comprise the majority of the earth's crust, as well as the other...

 minerals. One type, called pallasite
Pallasite
A pallasite is a type of stony–iron meteorite.-Structure and composition:It consists of cm-sized olivine crystals of peridot quality in an iron-nickel matrix. Coarser metal areas develop Widmanstätten patterns upon etching...

s, 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 mesosiderite
Mesosiderite
Mesosiderites are a class of stony–iron meteorites consisting of about equal parts of metallic nickel-iron and silicate. They are breccias with an irregular texture; silicates and metal occur often in lumps or pebbles as well as in fine-grained intergrowths...

s.

Tektites (from Greek tektos, molten) are not themselves meteorites, but are rather natural glass objects up to a few centimeters in size which 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
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 as volcanic ejecta, but this theory has lost much of its support over the last few decades.

Falls



Most meteorite falls
Meteorite falls
Meteorite falls, also called observed falls, are those meteorites that were witnessed by people or automated devices as they moved through the atmosphere or hit the Earth, and were subsequently collected. All other meteorites are called "finds"...

 are recovered on the basis of eye-witness accounts of the fireball or the actual impact of the object on the ground, or both. Therefore, despite the fact that meteorites actually fall with virtually equal probability everywhere on Earth, verified meteorite falls tend to be concentrated in areas with high human population
World population
The world population is the total number of living humans on the planet Earth. As of today, it is estimated to be  billion by the United States Census Bureau...

 densities such as Europe, Japan, and northern India
North India
North India, known natively as Uttar Bhārat or Shumālī Hindustān , is a loosely defined region in the northern part of India. The exact meaning of the term varies by usage...

.

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
Príbram
Příbram is a city in the Central Bohemian Region of the Czech Republic with a population of 35,147. The city is located on the Litavka river and the foothills of Brdy, 60 kilometers south-west of Prague, the country's capital...

 meteorite, which fell in Czechoslovakia
Czechoslovakia
Czechoslovakia or Czecho-Slovakia was a sovereign state in Central Europe which existed from October 1918, when it declared its independence from the Austro-Hungarian Empire, until 1992...

 (now the Czech Republic) in 1959. In this case, two cameras used to photograph meteor
METEOR
METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...

s 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 Pribram 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
Smithsonian Astrophysical Observatory
The Smithsonian Astrophysical Observatory is a research institute of the Smithsonian Institution headquartered in Cambridge, Massachusetts, where it is joined with the Harvard College Observatory to form the Harvard-Smithsonian Center for Astrophysics .-History:The SAO was founded in 1890 by...

 from 1963 to 1975 in the midwestern US
Midwestern United States
The Midwestern United States is one of the four U.S. geographic regions defined by the United States Census Bureau, providing an official definition of the American Midwest....

. 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
European Fireball Network
European Fireball Network is an international organization based in Central Europe . Its purpose is systematic and simultaneous night observation of meteors and other nebular objects from several stations for scientific purposes....

, a descendant of the original Czech program that recovered Pribram, led to the discovery and orbit calculations for the Neuschwanstein meteorite in 2002.

Finds


Until the 20th century, only a few hundred meteorite finds had ever been discovered. Over 80% of these were iron and stony-iron meteorites, which are easily distinguished from local rocks. To this day, few stony meteorites are reported each year that can be considered to be "accidental" finds. The reason there are now over 30,000 meteorite finds in the world's collections started with the discovery by Harvey H. Nininger
Harvey H. Nininger
Harvey Harlow Nininger , American meteorite collector, self-taught meteoriticist and educator, revived interest in the scientific study of meteorites in the 1930s, and assembled the largest personal collection of meteorites up to that time. He founded the American Meteorite Museum, which was first...

 that meteorites are much more common on the surface of the Earth than was previously thought.

The Great Plains of the US


Nininger's strategy was to search for meteorites in the Great Plains
Great Plains
The Great Plains are a broad expanse of flat land, much of it covered in prairie, steppe and grassland, which lies west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...

 of the United States, where the land was largely cultivated and the soil contained few rocks. Between the late 1920s and the 1950s, he traveled across the region, educating local people about what meteorites looked like and what to do if they thought they had found one, for example, in the course of clearing a field. The result was the discovery of over 200 new meteorites, mostly stony types.

In the late 1960s, Roosevelt County, New Mexico
Roosevelt County, New Mexico
-2010:Whereas according to the 2010 U.S. Census Bureau:*76.9% White*1.8% Black*1.3% Native American*0.9% Asian*0.0% Native Hawaiian or Pacific Islander*3.2% Two or more races*15.9% Other races*39.9% Hispanic or Latino -2000:...

 in the Great Plains 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 found by a single person, Mr. 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
Hardpan
In soil science, agriculture and gardening, hardpan or ouklip is a general term for a dense layer of soil, usually found below the uppermost topsoil layer. There are different types of hardpan, all sharing the general characteristic of being a distinct soil layer that is largely impervious to water...

 layer. During the dustbowl era, the loose soil was blown off, leaving any rocks and meteorites that were present stranded on the exposed surface.

Antarctica



A few meteorites were found in Antarctica between 1912 and 1964. In 1969, the 10th Japanese Antarctic Research Expedition found nine meteorites on a blue ice field
Blue ice (glacial)
Blue ice occurs when snow falls on a glacier, is compressed, and becomes part of a glacier that winds its way toward a body of water . During its travels, air bubbles that are trapped in the ice are squeezed out, and the size of the ice crystals increases, making it clear...

 near the Yamato Mountains. With this discovery, came the realization that movement of ice sheet
Ice sheet
An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km² , thus also known as continental glacier...

s might act to concentrate meteorites in certain areas. After a dozen other specimens were found in the same place in 1973, a Japanese expedition was launched in 1974 dedicated to the search for meteorites. This team recovered nearly 700 meteorites.

Shortly thereafter, the United States began its own program to search for Antarctic meteorites, operating along the Transantarctic Mountains
Transantarctic Mountains
The three largest mountain ranges on the Antarctic continent are the Transantarctic Mountains , the West Antarctica Ranges, and the East Antarctica Ranges. The Transantarctic Mountains compose a mountain range in Antarctica which extend, with some interruptions, across the continent from Cape Adare...

 on the other side of the continent: the ANtarctic Search for METeorites (ANSMET
ANSMET
ANSMET is a program funded by the Office of Polar Programs of the National Science Foundation that looks for meteorites in the Transantarctic Mountains. This geographical area serves as a collection point for meteorites that have originally fallen on the extensive high-altitude ice fields...

) program. European teams, starting with a consortium called "EUROMET" in the late 1980s, 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).

Australia


At about the same time as meteorite concentrations were being discovered in the cold desert of Antarctica, collectors discovered that many meteorites could also be found in the hot deserts of Australia
Deserts of Australia
Deserts cover a large portion of the land in Australia. Most of the deserts lie in the central and north-western part of the country. The largest part of Australia is desert or semi-arid...

. Several dozen meteorites had already been found in the Nullabor region of Western
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...

 and South Australia
South Australia
South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...

. Systematic searches between about 1971 and the present recovered over 500 more, ~300 of which are currently well characterized. The meteorites can be found in this region because the land presents a flat, featureless, plain covered by limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

. In the extremely arid climate, there has been relatively little weathering
Weathering
Weathering is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters...

 or sedimentation
Sedimentation
Sedimentation is the tendency for particles in suspension to settle out of the fluid in which they are entrained, and come to rest against a barrier. This is due to their motion through the fluid in response to the forces acting on them: these forces can be due to gravity, centrifugal acceleration...

 on the surface for tens of thousands of years, allowing meteorites to accumulate without being buried or destroyed. The dark colored meteorites can then be recognized among the very different looking limestone pebbles and rocks.

The Sahara and rising commercialization


In 1986-87, a German team installing a network of seismic stations while prospecting for oil discovered about 65 meteorites on a flat, desert plain about 100 km southeast of Dirj (Daraj), Libya
Libya
Libya is an African country in the Maghreb region of North Africa bordered by the Mediterranean Sea to the north, Egypt to the east, Sudan to the southeast, Chad and Niger to the south, and Algeria and Tunisia to the west....

. A few years later, a desert enthusiast saw photographs of meteorites being recovered by scientists in Antarctica, and thought that he had seen similar occurrences in northern Africa
North Africa
North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...

. In 1989, he recovered about 100 meteorites from several distinct locations in Libya and Algeria. Over the next several years, he and others who followed found at least 400 more meteorites. The find locations were generally in regions known as regs
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...

 or hamada
Hamada
A hamada is a type of desert landscape consisting of largely barren, hard, rocky plateaus, with very little sand. A hamada may sometimes also be called a reg , though this more properly refers to a stony plain rather than a highland.Hamadas exist in contrast to ergs, which are large areas of...

s: flat, featureless areas covered only by small pebbles and minor amounts of sand. Dark-colored meteorites can be easily spotted in these places, where they have also been well-preserved due to the arid climate, and in the case of the Dal al Gani meteorite field, favorable geology consisting of basic
Base (chemistry)
For the term in genetics, see base A base in chemistry is a substance that can accept hydrogen ions or more generally, donate electron pairs. A soluble base is referred to as an alkali if it contains and releases hydroxide ions quantitatively...

 rocks (clays, dolomite
Dolomite
Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....

s, and limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

s) and lacking erosive quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

 sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...

.

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
Scientific method
Scientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering empirical and measurable evidence subject to specific principles of...

. 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 over 2000.

As word spread in Saharan countries about the growing profitability of the meteorite trade, meteorite markets came into existence, especially in Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...

, fed by nomads and local people who combed the deserts looking for specimens to sell. Many thousands of meteorites have been distributed in this way, most of which lack any information about how, when, or where they were discovered. These are the so-called "Northwest Africa" meteorites.

Arabian Peninsula



In 1999, meteorite hunters discovered that the desert in southern and central Oman
Oman
Oman , officially called the Sultanate of Oman , is an Arab state in southwest Asia on the southeast coast of the Arabian Peninsula. It is bordered by the United Arab Emirates to the northwest, Saudi Arabia to the west, and Yemen to the southwest. The coast is formed by the Arabian Sea on the...

 were also favorable for the collection of many specimens. The gravel plains in the Dhofar
Dhofar
The Dhofar region lies in Southern Oman, on the eastern border with Yemen. Its mountainous area covers and has a population of 215,960 as of the 2003 census. The largest town in the region is Salalah. Historically, it was the chief source of frankincense in the world. However, its frankincense...

 and Al Wusta
Al Wusta Region (Oman)
Al Wusta is one of the regions of Oman. Its capital is Haima .Al Wusta Region consists of four wilayat: Haima, Duqm, Mahout and Al Jazer....

 regions of Oman, south of the sandy deserts of the Rub' al Khali
Empty Quarter
The Rub' al Khali or Empty Quarter is one of the largest sand deserts in the world, encompassing most of the southern third of the Arabian Peninsula, including most of Saudi Arabia and areas of Oman, the United Arab Emirates, and Yemen. The desert covers some The Rub' al Khali or Empty Quarter...

, had yielded about 5,000 meteorites as of mid-2009. Included among these are a large number of lunar
Lunar meteorite
A Lunar meteorite is a meteorite that is known to have originated on the Moon.-Discovery:In January 1982, John Schutt, leading an expedition in Antarctica for the ANSMET program, found a meteorite that he recognized to be unusual...

 and Martian
Mars meteorite
A martian meteorite is a rock that formed on the planet Mars, was ejected from Mars by the impact of an asteroid or comet, and landed on the Earth. Of over 53000 meteorites that have been found on Earth, 99 are martian...

 meteorites, making Oman a particularly important area both for scientists and collectors. Early expeditions to Oman were mainly done by commercial meteorite dealers, however international teams of Omani and European scientists have also now collected specimens.

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
International incident
An international incident is a seemingly relatively small or limited action or clash that results in a wider dispute between two or more nation-states...

, as its implementation actually 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 U.S. as well as several other European countries.

The Black Stone
Black Stone
The Black Stone is the eastern cornerstone of the Kaaba, the ancient stone building towards which Muslims pray, in the center of the Grand Mosque in Mecca, Saudi Arabia. It is revered by Muslims as an Islamic relic, which according to Muslim tradition dates back to the time of Adam and Eve.The...

 in the wall of the Kaaba
Kaaba
The Kaaba is a cuboid-shaped building in Mecca, Saudi Arabia, and is the most sacred site in Islam. The Qur'an states that the Kaaba was constructed by Abraham, or Ibraheem, in Arabic, and his son Ishmael, or Ismaeel, as said in Arabic, after he had settled in Arabia. The building has a mosque...

 in Mecca
Mecca
Mecca is a city in the Hijaz and the capital of Makkah province in Saudi Arabia. The city is located inland from Jeddah in a narrow valley at a height of above sea level...

 is thought to be a meteorite by some secular historians, but there is little support for this in the scientific literature

The American Southwest


Beginning in the mid-1990s, amateur meteorite hunters began scouring the arid areas of the southwestern United States
Southwestern United States
The Southwestern United States is a region defined in different ways by different sources. Broad definitions include nearly a quarter of the United States, including Arizona, California, Colorado, Nevada, New Mexico, Oklahoma, Texas and Utah...

. To date, meteorites numbering possibly into the thousands have been recovered from the Mojave
Mojave Desert
The Mojave Desert occupies a significant portion of southeastern California and smaller parts of central California, southern Nevada, southwestern Utah and northwestern Arizona, in the United States...

, Sonoran, Great Basin
Great Basin
The Great Basin is the largest area of contiguous endorheic watersheds in North America and is noted for its arid conditions and Basin and Range topography that varies from the North American low point at Badwater Basin to the highest point of the contiguous United States, less than away at the...

, and Chihuahuan Desert
Chihuahuan Desert
The Chihuahuan Desert is a desert, and an ecoregion designation, that straddles the U.S.-Mexico border in the central and northern portions of the Mexican Plateau, bordered on the west by the extensive Sierra Madre Occidental range, and overlaying northern portions of the east range, the Sierra...

s, with many being recovered on dry lake
Dry lake
Dry lakes are ephemeral lakebeds, or a remnant of an endorheic lake. Such flats consist of fine-grained sediments infused with alkali salts. Dry lakes are also referred to as alkali flats, sabkhas, playas or mud flats...

 beds. Significant finds include the Superior Valley 014 Acapulcoite, one of two of its type found within the United States as well as the Blue Eagle meteorite, the first Rumuruti-type chondrite yet found in the Americas. Perhaps the most notable find in recent years has been the Los Angeles meteorite, a martian meteorite that was reportedly found by Robert Verish.
A number of finds from the American Southwest have yet to be formally submitted to the Meteorite Nomenclature Committee, as many finders think it is unwise to publicly state the coordinates of their discoveries for fear of confiscation by the federal government, and of 'poaching' by other hunters at known find sites.
Several of the meteorites found recently are currently on display in the Griffith Observatory
Griffith Observatory
Griffith Observatory is in Los Angeles, California, United States. Sitting on the south-facing slope of Mount Hollywood in L.A.'s Griffith Park, it commands a view of the Los Angeles Basin, including downtown Los Angeles to the southeast, Hollywood to the south, and the Pacific Ocean to the southwest...

 in Los Angeles.

Meteorites in history


In the 1970s a stone meteorite was uncovered during an archaeological dig at Danebury Iron Age hillfort, Danebury England. It was found deposited part way down in an Iron Age pit. Since it must have been deliberately placed there, this could indicate one of the first (known) human finds of a meteorite in Europe.

Some Native Americans treated meteorites as ceremonial objects. In 1915, a 135-pound iron meteorite was found in a Sinagua
Sinagua
The Sinagua were a pre-Columbian cultural group occupying an area in central Arizona between the Little Colorado River and the Salt River including the Verde Valley and significant portions of the Mogollon Rim country between approximately 500 AD and 1425 AD.Early Sinagua sites consist of pit houses...

 (c.1100-1200 AD) burial cyst near Camp Verde, Arizona
Camp Verde, Arizona
Camp Verde is a town in Yavapai County, Arizona, United States. According to 2006 Census Bureau estimates, the population of the town is 10,610....

, respectfully wrapped in a feather cloth. A small pallasite was found in a pottery jar in an old burial found at Pojoaque Pueblo, New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

. 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 burial mounds
Tumulus
A tumulus is a mound of earth and stones raised over a grave or graves. Tumuli are also known as barrows, burial mounds, Hügelgrab or kurgans, and can be found throughout much of the world. A tumulus composed largely or entirely of stones is usually referred to as a cairn...

, and the discovery of the Winona meteorite in a Native American stone-walled crypt.


Indigenous peoples
Indigenous peoples
Indigenous peoples are ethnic groups that are defined as indigenous according to one of the various definitions of the term, there is no universally accepted definition but most of which carry connotations of being the "original inhabitants" of a territory....

 often prized iron-nickel meteorites as an easy, if limited, source of iron metal. For example, the Inuit used chips of the Cape York meteorite
Cape York meteorite
The Cape York meteorite is named for Cape York, the location of its discovery in Savissivik, Greenland, and is one of the largest iron meteorites in the world.-History:The meteorite collided with Earth nearly 10,000 years ago...

 to form cutting edges for tools and spear tips.

The German physicist, Ernst Florens Chladni, was the first to publish the then audacious idea that that meteorites were actually rocks from space. He published his booklet, "On the Origin of the Pallas Iron and Others Similar to it, and on Some Associated Natural Phenomena", in 1794. 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 10 years before a general acceptance of the origin of meteorites was achieved through the work of the French scientist Jean-Baptiste Biot
Jean-Baptiste Biot
Jean-Baptiste Biot was a French physicist, astronomer, and mathematician who established the reality of meteorites, made an early balloon flight, and studied the polarization of light.- Biography :...

 and the British chemist, Edward Howard
Edward Charles Howard
Edward Charles Howard FRS the youngest son of Charles Howard, 11th Duke of Norfolk, was a British chemist who has been described as the first chemical engineer of any eminence....

. Biot's study, initiated by the French Academy of Sciences
French Academy of Sciences
The French Academy of Sciences is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research...

, was compelled by a meteorite fall of thousands of meteorites on April 26, 1803 from the skies of L'Aigle
L'Aigle
L'Aigle is a commune in the Orne department in Basse-Normandie in north-western France.This commune used to be known as Laigle. According to Orderic Vitalis, the nest of an eagle was discovered during the construction of the castle....

, France.

One of the leading theories
Theory
The English word theory was derived from a technical term in Ancient Greek philosophy. The word theoria, , meant "a looking at, viewing, beholding", and referring to contemplation or speculation, as opposed to action...

 for the cause of the Cretaceous–Tertiary extinction event that included the dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

s is a large meteorite impact. The Chicxulub Crater
Chicxulub Crater
The Chicxulub crater is an ancient impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is located near the town of Chicxulub, after which the crater is named...

 has been identified as the site of this impact. There has been a lively scientific debate as to whether other major extinctions, including the ones at the end of the Permian
Permian-Triassic extinction event
The Permian–Triassic extinction event, informally known as the Great Dying, was an extinction event that occurred 252.28 Ma ago, forming the boundary between the Permian and Triassic geologic periods, as well as the Paleozoic and Mesozoic eras...

 and Triassic
Triassic-Jurassic extinction event
The Triassic–Jurassic extinction event marks the boundary between the Triassic and Jurassic periods, , and is one of the major extinction events of the Phanerozoic eon, profoundly affecting life on land and in the oceans. In the seas a whole class and twenty percent of all marine families...

 periods might also have been the result of large impact events, but the evidence is much less compelling than for the end Cretaceous extinction.
There are several reported instances of falling meteorites having killed both people and livestock, but a few of these appear more credible than others. The most infamous reported fatality from a meteorite impact is that of an Egyptian dog that was killed in 1911, although this report is highly disputed. This particular meteorite fall was identified in the 1980s as Martian
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

 in origin. However, there is substantial evidence that the meteorite known as Valera hit and killed a cow upon impact, nearly dividing the animal in two, and similar unsubstantiated reports of a horse being struck and killed by a stone of the New Concord fall also abound. Throughout history, many first and second-hand reports of meteorites falling on and killing both humans and other animals abound, but none have been well documented.

The first known modern case of a human hit by a space rock occurred on 30 November 1954 in Sylacauga, Alabama
Sylacauga, Alabama
Sylacauga is a city in Talladega County, Alabama, United States. At the 2000 census the population was 12,616.Nicknames for Sylacauga include: "The Marble City," "Buzzard's Roost" and "Sly Town"....

. There a 4 kg stone chondrite crashed through a roof and hit Ann Hodges in her living room
Living room
A living room, also known as sitting room, lounge room or lounge , is a room for entertaining adult guests, reading, or other activities...

 after it bounced off her radio. She was badly bruised. The Hodges meteorite, or Sylacauga meteorite, is currently on exhibit at the Alabama Museum of Natural History
Alabama Museum of Natural History
The Alabama Museum of Natural History is the state's natural history museum, located in Smith Hall at the University of Alabama campus in Tuscaloosa. The oldest museum in the state, it was founded in 1831. The exhibits depict the natural diversity of Alabama from the Age of Dinosaurs, the Coal Age,...

.

Another claim was put forth by a young boy who stated that he had been hit by a small (~3 gram
Gram
The gram is a metric system unit of mass....

) stone of the Mbale meteorite fall from Uganda
Uganda
Uganda , officially the Republic of Uganda, is a landlocked country in East Africa. Uganda is also known as the "Pearl of Africa". It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by...

, and who stood to gain nothing from this assertion. The stone reportedly fell through a number of banana leaves before striking the boy on the head, causing little to no pain, as it was small enough to have been slowed by both friction
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and/or material elements sliding against each other. There are several types of friction:...

 with the atmosphere as well as that with banana leaves, before striking the boy.

Several persons have since claimed to have been struck by "meteorites" but no verifiable meteorites have resulted.

Meteorite falls may also be the source of cultish worship. The cult in the Temple of Artemis (Diana) at Ephesus
Temple of Artemis
The Temple of Artemis , also known less precisely as the Temple of Diana, was a Greek temple dedicated to a goddess Greeks identified as Artemis and was one of the Seven Wonders of the Ancient World. It was situated at Ephesus , and was completely rebuilt three times before its eventual destruction...

, one of the Seven Wonders of the Ancient World
Seven Wonders of the Ancient World
The Seven Wonders of the World refers to remarkable constructions of classical antiquity listed by various authors in guidebooks popular among the ancient Hellenic tourists, particularly in the 1st and 2nd centuries BC...

 possibly originated with the observation of a meteorite fall which was understood by contemporaries to have fallen to the earth from Zeus, the principal Greek deity.

Meteorite weathering



Most meteorites date from the oldest times in the solar system and are by far the oldest material available on our planet. However, despite their age, they are pretty vulnerable to terrestrial environment: water, salt, oxygen attack the meteorites as soon they reach the ground.

The terrestrial alteration of meteorites is called weathering
Meteorite weathering
Meteorite weathering is the terrestrial alteration of a meteorite. Most meteorites date from the oldest times in the Solar System and are by far the oldest material available on our planet...

. In order to quantify the degree of alteration that a meteorite experienced, several qualitative weathering indices have been applied to Antarctic and desertic samples.

The most known weathering scale, used for stone meteorites, ranges from W0 (pristine state) to W6 (heavy alteration).

Notable meteorites

  • Allende
    Allende meteorite
    The Allende meteorite is the largest carbonaceous chondrite ever found on Earth. The fireball was witnessed at 1:05 a.m. on February 8, 1969, falling over the Mexican state of Chihuahua. After breaking up in the atmosphere, an extensive search for pieces was conducted and it is often described as...

    , largest known carbonaceous chondrite
    Carbonaceous chondrite
    Carbonaceous chondrites or C chondrites are a class of chondritic meteorites comprising at least 7 known groups and many ungrouped meteorites. They include some of the most primitive known meteorites...

     (Chihuahua, Mexico, 1969).
  • Allan Hills 81005 - First meteorite determined to be of lunar origin
    Lunar meteorite
    A Lunar meteorite is a meteorite that is known to have originated on the Moon.-Discovery:In January 1982, John Schutt, leading an expedition in Antarctica for the ANSMET program, found a meteorite that he recognized to be unusual...

    .
  • Allan Hills 84001
    ALH84001
    Allan Hills 84001 is a meteorite that was found in Allan Hills, Antarctica on December 27, 1984 by a team of U.S. meteorite hunters from the ANSMET project. Like other members of the group of SNCs , ALH 84001 is thought to be from Mars. However, it does not fit into any of the previously...

     - Mars meteorite
    Mars meteorite
    A martian meteorite is a rock that formed on the planet Mars, was ejected from Mars by the impact of an asteroid or comet, and landed on the Earth. Of over 53000 meteorites that have been found on Earth, 99 are martian...

     that was claimed to prove the existence of life on Mars
    Mars
    Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

    .
  • The Bacubirito Meteorite (Meteroito de Bacubirito) - A meteorite estimated to weigh between 20 and 30 tons. It is on display at the Centro de Ciencias de Sinaloa in Culiacán
    Culiacán
    Culiacán is a city in northwestern Mexico, the largest city in the state of Sinaloa as well as its capital and capital of the municipality of Culiacán. With 675,773 inhabitants in the city , and 858,638 in the municipality, it is the largest city in the state of Sinaloa...

    , Sinaloa
    Sinaloa
    Sinaloa officially Estado Libre y Soberano de Sinaloa is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 18 municipalities and its capital city is Culiacán Rosales....

    , Mexico.
  • Canyon Diablo
    Canyon Diablo meteorite
    The Canyon Diablo meteorite comprises many fragments of the asteroid that impacted at Barringer Crater , Arizona, USA. Meteorites have been found around the crater rim, and are named for nearby Canyon Diablo, which lies about three to four miles west of the crater.-History:The asteroid fell about...

     - Iron meteorite used by prehistoric Native Americans
    Native Americans in the United States
    Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...

    .
  • Cape York
    Cape York meteorite
    The Cape York meteorite is named for Cape York, the location of its discovery in Savissivik, Greenland, and is one of the largest iron meteorites in the world.-History:The meteorite collided with Earth nearly 10,000 years ago...

     - One of the largest meteorites in the world. A 34 ton fragment called "Ahnighito", is exhibited at the American Museum of Natural History
    American Museum of Natural History
    The American Museum of Natural History , located on the Upper West Side of Manhattan in New York City, United States, is one of the largest and most celebrated museums in the world...

    ; the largest meteorite on exhibit in any museum.
  • Elbogen
    Elbogen (meteorite)
    Elbogen , also the Loket Iron , is an iron meteorite that fell in the village of Loket, Karlovy Vary region, in the Czech Republic, about the year 1400. Also known during the Middle Ages as the "bewitched burgrave" of Elbogen, due to a cursed Count at the Elbogen castle, it is the oldest of 15...

     - The oldest recorded meteorite in the Czech Republic
    Czech Republic
    The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....

    , also known as the "betwitched burgrave".
  • Huckitta
    Huckitta
    Huckitta is a pallasite meteorite recovered in 1937 from Huckitta Cattle Station, Northern Territory, Australia.-History:In 1924 a meteoritic mass of 1084 grams was found by Herbert Basedow on Burt Plain , about 17 km north of Alice Springs. This mass was called Alice Springs...

     - The largest main mass Pallasite.
  • Hoba
    Hoba meteorite
    Hoba is a meteorite that lies on the farm "Hoba West", not far from Grootfontein, in the Otjozondjupa Region of Namibia. It has been uncovered but, because of its large mass, has never been moved from where it fell...

     - The largest known meteorite.
  • Hrascina
    Hrašcina
    Hrašćina is a municipality in the Krapina-Zagorje County in Croatia. According to the 2001 census, there are 1,826 inhabitants in the area, absolute majority which are Croats....

     meteorite - Croatia
    Croatia
    Croatia , officially the Republic of Croatia , is a unitary democratic parliamentary republic in Europe at the crossroads of the Mitteleuropa, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers ...

    n meteorite first speculated as originating from outer space.
  • Kaidun
    Kaidun meteorite
    Kaidun is a meteorite that fell on 3 December 1980 on a Soviet military base near what is now Al-Khuraybah in Yemen. A fireball was observed travelling from the northwest to the southeast, and a single stone weighing about 2 kilograms was recovered from a small impact pit...

     - Possibly from the martian moon
    Mars' natural satellites
    Mars has two small moons, Phobos and Deimos, which are thought to be captured asteroids. Both satellites were discovered in 1877 by Asaph Hall, and are named after the characters Phobos and Deimos who, in Greek mythology, accompanied their father Ares, god of war, into battle...

     Phobos
    Phobos (moon)
    Phobos is the larger and closer of the two natural satellites of Mars. Both moons were discovered in 1877. With a mean radius of , Phobos is 7.24 times as massive as Deimos...

    .
  • Murchison
    Murchison meteorite
    The Murchison meteorite is named after Murchison, Victoria, in Australia. It is one of the most studied meteorites due to its large mass , the fact that it was an observed fall, and it belongs to a group of meteorites rich in organic compounds....

     - A carbonaceous
    Carbonaceous
    Carbonaceous is the defining attribute of a substance rich in carbon. Particularly, carbonaceous hydrocarbons are very unsaturated, high-molecular-weight hydrocarbons, having an elevated carbon:hydrogen ratio....

     chondrite
    Chondrite
    Chondrites are stony meteorites that have not been modified due to melting or differentiation of the parent body. They formed when various types of dust and small grains that were present in the early solar system accreted to form primitive asteroids...

     found to contain nucleobases - the building block of life.
  • Nōgata - The oldest meteorite whose fall can be dated precisely (to May 19, 861, at Nōgata
    Nogata, Fukuoka
    is a city located in Fukuoka prefecture, Japan, on the island of Kyushu in southern Japan. Located near Kitakyūshū and Iizuka, Nōgata is in the center of the Chikuhō region of Fukuoka....

    )
  • Orgueil - Object of a hoax that involved adhering a seed
    Seed
    A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

     to part of the meteorite.
  • Sikhote-Alin
    Sikhote-Alin Meteorite
    Sikhote-Alin is an iron meteorite that fell in 1947 on the Sikhote-Alin Mountains in eastern Siberia. This fall is unique in the history of meteorites. Though large iron meteorite falls had been witnessed previously and fragments recovered, never before in recorded history had a fall of this...

     - Massive iron meteorite impact event
    Impact event
    An impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Throughout recorded history, hundreds of minor impact events have been reported, with some occurrences causing deaths, injuries, property damage or other significant...

     that occurred on February 12, 1947.
  • Tucson Ring -- Ring shaped meteorite, used by a blacksmith as a table, in Tucson AZ. Currently at the Smithsonian.
  • Willamette
    Willamette Meteorite
    The Willamette Meteorite, officially named Willamette, is an iron-nickel meteorite discovered in the U.S. state of Oregon. It is the largest meteorite found in North America and the sixth largest in the world...

     - The largest meteorite ever found in the United States.
  • The Peruvian meteorite event
    Carancas impact event
    The Carancas impact event refers to the fall of the Carancas chondritic meteorite on September 15, 2007, near the village of Carancas in Peru, close to the Bolivian border and Lake Titicaca. The impact created a crater and scorched earth around its location...

     - On 15 September 2007, a stony meteorite that may have weighed as much as 4000 kilograms created a crater 13 meters in diameter near the village of Carancas, Peru
    Peru
    Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

    .

Apart from meteorites fallen onto the Earth, "Heat Shield Rock
Heat Shield Rock
Heat Shield Rock is a basketball-sized iron-nickel meteorite found on Mars by the Mars rover Opportunity in January 2005. The meteorite was formally named Meridiani Planum meteorite by the Meteoritical Society in October, 2005 .-Discovery:Opportunity encountered the meteorite entirely by chance,...

" is a meteorite which was found on Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

, and two tiny fragments of asteroids were found among the samples collected on the Moon by Apollo 12
Apollo 12
Apollo 12 was the sixth manned flight in the American Apollo program and the second to land on the Moon . It was launched on November 14, 1969 from the Kennedy Space Center, Florida, four months after Apollo 11. Mission commander Charles "Pete" Conrad and Lunar Module Pilot Alan L...

 (1969) and Apollo 15
Apollo 15
Apollo 15 was the ninth manned mission in the American Apollo space program, the fourth to land on the Moon and the eighth successful manned mission. It was the first of what were termed "J missions", long duration stays on the Moon with a greater focus on science than had been possible on previous...

 (1971) astronauts.

Notable large impact craters

  • Acraman crater
    Acraman crater
    Acraman crater is a deeply eroded impact crater in the Gawler Ranges of South Australia. Its location is marked by Lake Acraman, a circular ephemeral playa lake about 20 km in diameter....

     in South Australia (90 km diameter)
  • Brent crater
    Brent crater
    The Brent crater is an impact crater in both the geographic township of Deacon, Unorganized South Nipissing District and the municipal township of Papineau-Cameron in Nipissing District, northeastern Ontario, Canada, located north of Cedar Lake in northern Algonquin Provincial Park. It is in...

     in northern Ontario
    Ontario
    Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

     (3.8 km diameter)
  • Chesapeake Bay impact crater
    Chesapeake Bay impact crater
    The Chesapeake Bay impact crater was formed by a bolide that impacted the eastern shore of North America about 35 million years ago, in the late Eocene epoch. It is one of the best-preserved "wet-target" or marine impact craters, and the largest known impact crater in the U.S...

     (90 km diameter)
  • Chicxulub Crater
    Chicxulub Crater
    The Chicxulub crater is an ancient impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is located near the town of Chicxulub, after which the crater is named...

     off the coast of Yucatán
    Yucatán
    Yucatán officially Estado Libre y Soberano de Yucatán is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 106 municipalities and its capital city is Mérida....

     (170 km diameter)
  • Clearwater Lakes
    Clearwater Lakes
    The Lac à l'Eau Claire , also called the Clearwater Lakes in English, Wiyasakami in Cree and Allait Qasigialingat by the Inuit, are a pair of circular lakes on the Canadian Shield in Quebec, Canada, near Hudson Bay.The lakes are actually a single body of water with a sprinkling of islands forming a...

     a double crater impact in Québec, Canada (26 km and 36 km in diameter)
  • Lonar crater in India (1.83 km diameter)
  • Manicouagan Reservoir
    Manicouagan Reservoir
    Manicouagan Reservoir is an annular lake in central Quebec, Canada. The lake covers an area of 1,942 km², and its eastern shore is accessible via Route 389. The island in the centre of the lake is known as René-Levasseur Island, and its highest point is Mount Babel...

     in Québec, Canada (100 km diameter)
  • Manson crater
    Manson crater
    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 Ma...

     in Iowa (38 km crater is buried)
  • Meteor Crater
    Meteor Crater
    Meteor Crater is a meteorite impact crater located approximately east of Flagstaff, near Winslow in the northern Arizona desert of the United States. Because the US Department of the Interior Division of Names commonly recognizes names of natural features derived from the nearest post office, the...

     in Arizona
    Arizona
    Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

    , also known as Barringer Crater, the first confirmed terrestrial impact crater. (1.2 km diameter)
  • Mjølnir impact crater in the Barents Sea
    Barents Sea
    The Barents Sea is a marginal sea of the Arctic Ocean, located north of Norway and Russia. Known in the Middle Ages as the Murman Sea, the sea takes its current name from the Dutch navigator Willem Barents...

     (40 km diameter)
  • Nördlinger Ries
    Nördlinger Ries
    The Nördlinger Ries is a large circular depression in western Bavaria, Germany, located north of the Danube in the district of Donau-Ries. The city of Nördlingen is located about southwest of the centre of the depression....

     crater in Bavaria, Germany (25 km diameter)
  • Popigai crater
    Popigai crater
    The Popigai crater in Siberia, Russia is tied with Manicouagan Crater as the fourth largest verified impact crater on Earth. A large bolide impact created the diameter crater 35.7 ± 0.2 million years ago during the late Eocene . The crater is 1½ hours from the outpost of Khatanga...

     in Russia (100 km diameter)
  • Siljan (lake)
    Siljan (lake)
    Siljan, in Dalarna in central Sweden, is Sweden's sixth largest lake. The cumulative area of Siljan and the adjacent, smaller lakes Orsasjön and Insjön is . Siljan reaches a maximum depth of , and its surface is situated above sea level...

     in Sweden, largest crater in Europe (52 km diameter)
  • Sudbury Basin
    Sudbury Basin
    The Sudbury Basin, also known as Sudbury Structure or the Sudbury Nickel Irruptive, is a major geologic structure in Ontario, Canada. It is the second-largest known impact crater or astrobleme on Earth, as well as one of the oldest....

     in Ontario, Canada (250 km diameter).
  • Vredefort Crater
    Vredefort crater
    Vredefort crater is the largest verified impact crater on Earth. It is located in the Free State Province of South Africa and named after the town of Vredefort, which is situated near its centre. The site is also known as the Vredefort dome or Vredefort impact structure...

     in South Africa, the largest known impact crater on Earth (300 km diameter from an estimated 10 km wide meteorite).

Notable disintegrating meteoroids

  • Tunguska event
    Tunguska event
    The Tunguska event, or Tunguska blast or Tunguska explosion, was an enormously powerful explosion that occurred near the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia, at about 7:14 a.m...

     in Siberia
    Siberia
    Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...

     1908 (no crater) (There is no direct evidence that it was a meteoroid)
  • Vitim event
    Vitim event
    The Vitim event or Bodaybo event is believed to be an impact by a bolide or comet nucleus in the Vitim River basin. It occurred near the town of Bodaybo in the Mamsko-Chuisky district of Irkutsk Oblast, Siberia, Russia on September 25, 2002 at approximately 10:00 p.m....

     in Siberia 2002 (no crater)

See also

  • Atmospheric focusing
    Atmospheric focusing
    Atmospheric focusing is a phenomenon occurring when a large shock wave is produced in the atmosphere, as in a nuclear explosion or large extraterrestrial object impact. The shock wave is refracted horizontally by density variations in the atmosphere so that it can have impacts in localized areas...

    , shockwave produced in the atmosphere by a meteor or other cause
  • Baetylus
    Baetylus
    Baetylus is a Semitic word denoting a sacred stone, which was supposedly endowed with life. According to ancient sources, these objects of worship were meteorites, which were dedicated to the gods or revered as symbols of the gods themselves...

    , a Semitic word denoting a sacred stone (often a meteorite)
  • Carbonaceous chondrite
    Carbonaceous chondrite
    Carbonaceous chondrites or C chondrites are a class of chondritic meteorites comprising at least 7 known groups and many ungrouped meteorites. They include some of the most primitive known meteorites...

    , a class of chondritic meteorites comprising at least seven known groups and many ungrouped
  • Carbonado
    Carbonado
    Carbonado, commonly known as the "Black Diamond", is a natural polycrystalline diamond found in alluvial deposits in the Central African Republic and Brazil. Its natural colour is black or dark grey, and it is more porous than other diamonds....

    , commonly known as "black diamond," is hypothesized to be of extraterrestrial origin
  • Center for Meteorite Studies
    Center for Meteorite Studies
    Founded in 1960, on the Tempe Campus of Arizona State University, the Center for Meteorite Studies houses the world's largest university-based meteorite collection. The collection contains specimens from over 1,600 separate meteorite falls and finds, and is actively used internationally for...

     at Arizona State University
  • Geminids
    Geminids
    The Geminids are a meteor shower caused by the object 3200 Phaethon, which is thought to be a Palladian asteroid. This would make the Geminids, together with the Quadrantids, the only major meteor showers not originating from a comet...

    , a recurring meteor shower caused by an object named 3200 Phaethon
    3200 Phaethon
    3200 Phaethon is an asteroid with an unusual orbit that brings it closer to the Sun than any other named asteroid . For this reason, it was named after the Greek myth of Phaëton, son of the sun god Helios...

  • Impact depth
    Impact depth
    The physicist Sir Isaac Newton first developed this idea to get rough approximations for the impact depth for projectiles traveling at high velocities.-Newton's approximation for the impact depth:...

     of projectiles traveling at high speed
  • Impact event
    Impact event
    An impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Throughout recorded history, hundreds of minor impact events have been reported, with some occurrences causing deaths, injuries, property damage or other significant...

    , the collision of a large meteorite, asteroid, comet, or other celestial object with a planet
  • Lake Siljan, an impact crater in Sweden
  • Leonids
    Leonids
    The Leonids is a prolific meteor shower associated with the comet Tempel-Tuttle. The Leonids get their name from the location of their radiant in the constellation Leo: the meteors appear to radiate from that point in the sky. They tend to peak in November.Earth moves through the meteoroid...

    , a prolific meteor shower associated with the comet Tempel-Tuttle
  • Meteor shower
    Meteor shower
    A meteor shower is a celestial event in which a number of meteors are observed to radiate from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at extremely high speeds on parallel trajectories. Most meteors are smaller...

  • Meteorite classification
  • Meteoritical Society
    Meteoritical Society
    The Meteoritical Society is a non-profit scholarly organization founded in 1933 to promote research and education in planetary science with emphasis on studies of meteorites and other extraterrestrial materials that further our understanding of the origin and history of the solar system.The...

    , scholarly organization specializing in meteorites
  • Near Earth Object
  • Neenach Meteorite, Los Angeles County, California
  • Solar System
    Solar System
    The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...

  • The British and Irish Meteorite Society
    The British and Irish Meteorite Society
    The British and Irish Meteorite Society is a group of 150+ Meteorite researchers and amateurs. The BIMS was formed in 2004 by the meteorite collectors Mark Ford and Dave Harris. The group provides a meteorite collecting and study focus for the UK and Ireland, and is the only meteorite group in the...

  • Temagami Magnetic Anomaly
    Temagami Magnetic Anomaly
    The Temagami Magnetic Anomaly, also called the Temagami Anomaly or the Wanapitei Anomaly, is a large buried geologic structure in Ontario, Canada, stretching from Lake Wanapitei in the west to Bear Island in Lake Temagami....

    , a large buried geologic structure in the Canadian Shield
  • Vatican Observatory
    Vatican Observatory
    The Vatican Observatory is an astronomical research and educational institution supported by the Holy See. Originally based in Rome, it now has headquarters and laboratory at the summer residence of the Pope in Castel Gandolfo, Italy, and an observatory at the Mount Graham International...


External links