![Namibie Hoba Meteorite 05](https://upload.wikimedia.org/wikipedia/commons/1/18/Namibie_Hoba_Meteorite_05.JPG)
A meteorite is a solid piece of debris from an object, such as a
comet
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ar ...
,
asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere.
...
, or
meteoroid
A meteoroid () is a small rocky or metallic body in outer space.
Meteoroids are defined as objects significantly smaller than asteroids, ranging in size from grains to objects up to a meter wide. Objects smaller than this are classified as micr ...
, that originates in
outer space
Outer space, commonly shortened to space, is the expanse that exists beyond Earth and its atmosphere and between celestial bodies. Outer space is not completely empty—it is a near-perfect vacuum containing a low density of particles, pred ...
and survives its passage through the atmosphere to reach the surface of a planet or
moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
. When the original object enters the atmosphere, various factors such as
friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction:
*Dry friction is a force that opposes the relative lateral motion of t ...
, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate energy. It then becomes a
meteor
A meteoroid () is a small rocky or metallic body in outer space.
Meteoroids are defined as objects significantly smaller than asteroids, ranging in size from grains to objects up to a meter wide. Objects smaller than this are classified as micr ...
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
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters ...
.
Meteorites that are recovered after being observed as they transit the atmosphere and
impact the Earth are called
meteorite falls
A meteorite fall, also called an observed fall, is a meteorite collected after its fall from outer space was observed by people or automated devices. Any other meteorite is called a " find". There are more than 1,100 documented falls listed in ...
. All others are known as
meteorite finds.
Meteorites have traditionally been divided into three broad categories: stony meteorites that are rocks, mainly composed of
silicate minerals
Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust.
In mineralogy, silica (silicon dioxide, ) is usually con ...
;
iron meteorite
Iron meteorites, also known as siderites, or ferrous meteorites, are a type of meteorite that consist overwhelmingly of an iron–nickel alloy known as meteoric iron that usually consists of two mineral phases: kamacite and taenite. Most iron met ...
s that are largely composed of
ferronickel
Ferroalloy refers to various alloys of iron with a high proportion of one or more other elements such as manganese (Mn), aluminium (Al), or silicon (Si). They are used in the production of steels and alloys. The alloys impart distinctive qualitie ...
; and stony-iron meteorites that contain large amounts of both metallic and rocky material. Modern
classification Classification is a process related to categorization, the process in which ideas and objects are recognized, differentiated and understood.
Classification is the grouping of related facts into classes.
It may also refer to:
Business, organizat ...
schemes divide meteorites into groups according to their structure, chemical and isotopic composition and mineralogy. "Meteorites" less than ~1 mm in diameter are classified as
micrometeorites
A micrometeorite is a micrometeoroid that has survived atmospheric entry, entry through the atmosphere of Earth, Earth's atmosphere. Usually found on Earth's surface, micrometeorites differ from meteorites in that they are smaller in size, more a ...
, 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.
Fall phenomena
Most meteoroids disintegrate when entering the Earth's atmosphere. Usually, five to ten a year are observed to fall and are subsequently recovered and made known to scientists. Few meteorites are large enough to create large
impact crater
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters ...
s. Instead, they typically arrive at the surface at their
terminal velocity
Terminal velocity is the maximum velocity (speed) attainable by an object as it falls through a fluid (air is the most common example). It occurs when the sum of the drag force (''Fd'') and the buoyancy is equal to the downward force of gravit ...
and, at most, create a small pit.
![Novato Meteorite Impact Pit](https://upload.wikimedia.org/wikipedia/commons/9/98/Novato_Meteorite_Impact_Pit.jpg)
Large meteoroids may strike the earth with a significant fraction of their
escape velocity
In celestial mechanics, escape velocity or escape speed is the minimum speed needed for a free, non- propelled object to escape from the gravitational influence of a primary body, thus reaching an infinite distance from it. It is typically ...
(second cosmic velocity), leaving behind a
hypervelocity
Hypervelocity is very high velocity, approximately over 3,000 meters per second (6,700 mph, 11,000 km/h, 10,000 ft/s, or Mach 8.8). In particular, hypervelocity is velocity so high that the strength of materials upon impact is v ...
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
The Odessa Meteor Crater is a meteorite crater in the southwestern part of Ector County, southwest of the city of Odessa of West Texas, United States. It is accessible approximately south of Interstate 20 at Exit 108 (Moss Road). This is one of ...
,
Wabar craters
The Wabar craters are impact craters located in Saudi Arabia first brought to the attention of Western scholars by British Arabist, explorer, writer and Colonial Office intelligence officer St John Philby, who discovered them while searching for ...
, 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
comet
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ar ...
s or
asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere.
...
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
The Tunguska event (occasionally also called the Tunguska incident) was an approximately 12-megaton explosion that occurred near the Podkamennaya Tunguska River in Yeniseysk Governorate (now Krasnoyarsk Krai), Russia, on the morning of June 30, ...
probably resulted from such an incident. Very large stony objects, hundreds of meters in diameter or more, weighing tens of millions of
ton
Ton is the name of any one of several units of measure. It has a long history and has acquired several meanings and uses.
Mainly it describes units of weight. Confusion can arise because ''ton'' can mean
* the long ton, which is 2,240 pounds
...
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 impact structure
The Morokweng impact structure is an impact structure buried beneath the Kalahari Desert near the town of Morokweng in South Africa's North West province, close to the border with Botswana
Botswana (, ), officially the Republic of Botsw ...
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 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
sonic boom
A sonic boom is a sound associated with shock waves created when an object travels through the air faster than the speed of sound. Sonic booms generate enormous amounts of sound energy, sounding similar to an explosion or a thunderclap to t ...
s as well as
shock wave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a med ...
s 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
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the ent ...
, their surfaces melt and experience
ablation
Ablation ( la, ablatio – removal) is removal or destruction of something from an object by vaporization, chipping, erosion, erosive processes or by other means. Examples of ablative materials are described below, and include spacecraft materi ...
. They can be sculpted into various shapes during this process, sometimes resulting in shallow thumbprint-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 solidifies into a thin fusion crust, which on most meteorites is black (on some
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 recrystalliz ...
s, the fusion crust may be very light-colored). On stony meteorites, the
heat-affected zone
In fusion welding, the heat-affected zone (HAZ) is the area of base material, either a metal or a thermoplastic, which is not melted but has had its microstructure and properties altered by welding or heat intensive cutting operations. The heat ...
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.
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
The term strewn field indicates the area where meteorites from a single fall are dispersed.
It is also often used for the area containing tektites produced by large meteorite impact.''Tektites in the geological record: showers of glass from the sky ...
. Strewn fields are commonly
elliptical
Elliptical may mean:
* having the shape of an ellipse, or more broadly, any oval shape
** in botany, having an elliptic leaf shape
** of aircraft wings, having an elliptical planform
* characterised by ellipsis (the omission of words), or by conc ...
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.
Classification
Most meteorites are stony meteorites, classed as
chondrite
A chondrite is a stony (non-metallic) meteorite that has not been modified, by either melting or differentiation of the parent body. They are formed when various types of dust and small grains in the early Solar System accreted to form primi ...
s and
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 recrystalliz ...
s. Only about 6% of meteorites are
iron meteorite
Iron meteorites, also known as siderites, or ferrous meteorites, are a type of meteorite that consist overwhelmingly of an iron–nickel alloy known as meteoric iron that usually consists of two mineral phases: kamacite and taenite. Most iron met ...
s or a blend of rock and metal, the
stony-iron meteorites. Modern classification of meteorites is complex. The review paper of Krot et al. (2007)
summarizes modern meteorite taxonomy.
About 86% of the meteorites are chondrites,
[Meteoritical Bulletin Database](_blank)
Lpi.usra.edu (1 January 2011). Retrieved on 17 December 2011. which are named for the small, round particles they contain. These particles, or
chondrule
A chondrule (from Ancient Greek χόνδρος ''chondros'', grain) is a round grain found in a chondrite. Chondrules form as molten or partially molten droplets in space before being accreted to their parent asteroids. Because chondrites repres ...
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
Organic matter, organic material, or natural organic matter refers to the large source of carbon-based compounds found within natural and engineered, terrestrial, and aquatic environments. It is matter composed of organic compounds that have c ...
, including
amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...
s, and
presolar grains
Presolar grains are interstellar solid matter in the form of tiny solid grains that originated at a time before the Sun was formed. Presolar stardust grains formed within outflowing and cooling gases from earlier presolar stars.
The stellar nuc ...
. Chondrites are typically about 4.55 billion years old and are thought to represent material from the
asteroid belt
The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called ...
that never coalesced into large bodies. Like
comet
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ar ...
s, chondritic asteroids are some of the oldest and most primitive materials in the
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...
. Chondrites are often considered to be "the building blocks of the planets".
About 8% of the meteorites are
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 recrystalliz ...
s (meaning they do not contain chondrules), some of which are similar to terrestrial
igneous rock
Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main The three types of rocks, rock types, the others being Sedimentary rock, sedimentary and metamorphic rock, metamorphic. Igneous rock ...
s. Most achondrites are also ancient rocks, and are thought to represent crustal material of differentiated planetesimals. One large family of achondrites (the
HED meteorite
HED meteorites are a clan (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 magm ...
s) may have originated on the parent body of the
Vesta Family
The Vesta family (adj. ''Vestian''; ) is a family of asteroids. The cratering family is located in the inner asteroid belt in the vicinity of its namesake and principal body, 4 Vesta. It is one of the largest asteroid families with more than ...
, 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
Apollo, grc, Ἀπόλλωνος, Apóllōnos, label=genitive , ; , grc-dor, Ἀπέλλων, Apéllōn, ; grc, Ἀπείλων, Apeílōn, label=Arcadocypriot Greek, ; grc-aeo, Ἄπλουν, Áploun, la, Apollō, la, Apollinis, label= ...
and
Luna
Luna commonly refers to:
* Earth's Moon, named "Luna" in Latin
* Luna (goddess), the ancient Roman personification of the Moon
Luna may also refer to:
Places Philippines
* Luna, Apayao
* Luna, Isabela
* Luna, La Union
* Luna, San Jose
Roma ...
programs. The other group is almost certainly from
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...
and constitutes the only materials from other planets ever recovered by humans.
About 5% of meteorites that have been seen to fall are
iron meteorite
Iron meteorites, also known as siderites, or ferrous meteorites, are a type of meteorite that consist overwhelmingly of an iron–nickel alloy known as meteoric iron that usually consists of two mineral phases: kamacite and taenite. Most iron met ...
s composed of iron-
nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...
alloy
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, ...
s, such as
kamacite
Kamacite is an alloy of iron and nickel, which is found on Earth only in meteorites. According to the International Mineralogical Association (IMA) it is considered a proper nickel-rich variety of the mineral native iron. The proportion iron:ni ...
and/or
taenite
Taenite is a mineral found naturally on Earth mostly in iron meteorites. It is an alloy of iron and nickel, with a chemical formula of and nickel proportions of 20% up to 65%.
The name is derived from the Greek ταινία for "band, ribbon" ...
. 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
In chemistry, a silicate is any member of a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula , where . The family includes orthosilicate (), metasilicate (), and pyrosilicate (, ). The name is al ...
minerals. One type, called
pallasites, 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
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 ...
s.
Tektites
Tektites (from grc, τηκτός , meaning 'molten') are gravel-sized bodies composed of black, green, brown or grey natural glass formed from terrestrial debris ejected during meteorite impacts. The term was coined by Austrian geologist Franz ...
(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
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
as volcanic ejecta, but this theory has lost much of its support over the last few decades.
Chemistry
In March 2015, NASA scientists reported that complex
organic compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...
s found in
DNA and
RNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...
, including
uracil
Uracil () (symbol U or Ura) is one of the four nucleobases in the nucleic acid RNA. The others are adenine (A), cytosine (C), and guanine (G). In RNA, uracil binds to adenine via two hydrogen bonds. In DNA, the uracil nucleobase is replaced by ...
,
cytosine
Cytosine () ( symbol C or Cyt) is one of the four nucleobases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an am ...
, and
thymine
Thymine () ( symbol T or Thy) is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The others are adenine, guanine, and cytosine. Thymine is also known as 5-methyluracil, a pyrimidine nu ...
, have been formed in the laboratory under
outer space
Outer space, commonly shortened to space, is the expanse that exists beyond Earth and its atmosphere and between celestial bodies. Outer space is not completely empty—it is a near-perfect vacuum containing a low density of particles, pred ...
conditions, using starting chemicals, such as
pyrimidine
Pyrimidine (; ) is an aromatic, heterocyclic, organic compound similar to pyridine (). One of the three diazines (six-membered heterocyclics with two nitrogen atoms in the ring), it has nitrogen atoms at positions 1 and 3 in the ring. The other ...
, found in meteorites. Pyrimidine and
polycyclic aromatic hydrocarbons
A polycyclic aromatic hydrocarbon (PAH) is a class of organic compounds that is composed of multiple aromatic rings. The simplest representative is naphthalene, having two aromatic rings and the three-ring compounds anthracene and phenanthrene. P ...
(PAHs) may have been formed in
red giant
A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses ()) in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around or ...
s or in
interstellar dust
Cosmic dust, also called extraterrestrial dust, star dust or space dust, is dust which exists in outer space, or has fallen on Earth. Most cosmic dust particles measure between a few molecules and 0.1 mm (100 micrometers). Larger particles are c ...
and gas clouds, according to the scientists.
In January 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 November 2019, scientists reported detecting sugar molecules in meteorites for the first time, including
ribose
Ribose is a simple sugar and carbohydrate with molecular formula C5H10O5 and the linear-form composition H−(C=O)−(CHOH)4−H. The naturally-occurring form, , is a component of the ribonucleotides from which RNA is built, and so this compo ...
, suggesting that chemical processes on
asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere.
...
s can produce some organic compounds fundamental to life, and supporting the notion of an
RNA world
The RNA world is a hypothetical stage in the evolutionary history of life on Earth, in which self-replicating RNA molecules proliferated before the evolution of DNA and proteins. The term also refers to the hypothesis that posits the existence ...
prior to a DNA-based
origin of life
In biology, abiogenesis (from a- 'not' + Greek bios 'life' + genesis 'origin') or the origin of life is the natural process by which life has arisen from non-living matter, such as simple organic compounds. The prevailing scientific hypothes ...
on Earth.
In April 2022, a Japanese group reported that they had found
adenine
Adenine () ( symbol A or Ade) is a nucleobase (a purine derivative). It is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The three others are guanine, cytosine and thymine. Its derivati ...
(A),
thymine
Thymine () ( symbol T or Thy) is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The others are adenine, guanine, and cytosine. Thymine is also known as 5-methyluracil, a pyrimidine nu ...
(T),
guanine
Guanine () ( symbol G or Gua) is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine (uracil in RNA). In DNA, guanine is paired with cytosine. The guanine nucleoside is called ...
(G),
cytosine
Cytosine () ( symbol C or Cyt) is one of the four nucleobases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an am ...
(C) and
uracil
Uracil () (symbol U or Ura) is one of the four nucleobases in the nucleic acid RNA. The others are adenine (A), cytosine (C), and guanine (G). In RNA, uracil binds to adenine via two hydrogen bonds. In DNA, the uracil nucleobase is replaced by ...
(U) inside carbon-rich meteorites. These compounds
are building blocks of
DNA and
RNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...
, the
genetic code
The genetic code is the set of rules used by living cells to translate information encoded within genetic material ( DNA or RNA sequences of nucleotide triplets, or codons) into proteins. Translation is accomplished by the ribosome, which links ...
of all
life
Life is a quality that distinguishes matter that has biological processes, such as signaling and self-sustaining processes, from that which does not, and is defined by the capacity for growth, reaction to stimuli, metabolism, energ ...
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"](_blank)
LiveScience, 28 April 2022
Weathering
Most meteorites date from the early Solar System and are by far the oldest extant material on Earth. Analysis of terrestrial
weathering
Weathering is the deterioration of rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms. Weathering occurs ''in situ'' (on site, with little or no movement), ...
due to water, salt, oxygen, etc. is used to quantify the degree of alteration that a meteorite has experienced. Several qualitative weathering indices have been applied to Antarctic and desertic samples.
[P. A. Bland, M. E. Zolensky, G. K. Benedix, M. A. Sephton. ']
Weathering of Chondritic Meteorites
''
The most commonly employed weathering scale, used for
ordinary chondrite
The ordinary chondrites (sometimes called the O chondrites) are a class of stony chondritic meteorites. They are by far the most numerous group, comprising 87% of all finds. Hence, they have been dubbed "ordinary". The ordinary chondrites are th ...
s, ranges from
W0 (pristine state) to
W6 (heavy alteration).
Fossil meteorites
"Fossil" meteorites are sometimes discovered by geologists. They represent the highly weathered remains of meteorites that fell to Earth in the remote past and were preserved in sedimentary deposits sufficiently well that they can be recognized through mineralogical and geochemical studies. The Thorsberg
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
quarry in Sweden has produced an anomalously large number – exceeding one hundred – fossil meteorites from the
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start ...
, nearly all of which are highly weathered L-chondrites that still resemble the original meteorite under a petrographic microscope, but which have had their original material almost entirely replaced by terrestrial secondary mineralization. The extraterrestrial provenance was demonstrated in part through isotopic analysis of
relict
A relict is a surviving remnant of a natural phenomenon.
Biology
A relict (or relic) is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas.
Geology and geomorphology
In geology, a r ...
spinel
Spinel () is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula in the cubic crystal system. Its name comes from the Latin word , which means ''spine'' in reference to its pointed crystals.
Properties
S ...
grains, a mineral that is common in meteorites, is insoluble in water, and is able to persist chemically unchanged in the terrestrial weathering environment. Scientists believe that these meteorites, which have all also been found in Russia and China, all originated from the
same source, a collision that occurred somewhere between Jupiter and Mars. One of these fossil meteorites, dubbed
Österplana 065
Österplana 065 (Öst 65) is an Ordovician fossil meteorite found in the Thorsberg quarry in Sweden on June 26, 2011, and scientifically described in 2016. Measuring 8×6.5×2 cm, it impacted the Earth 470 million years ago, during the Ordovician ...
, appears to represent a distinct type of meteorite that is "extinct" in the sense that it is no longer falling to Earth, the parent body having already been completely depleted from the reservoir of
near-Earth object
A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...
s.
Collection
A "meteorite fall", also called an "observed fall", is a meteorite collected after its arrival was observed by people or automated devices. Any other meteorite is called a "meteorite find". There are more than 1,100 documented falls listed in widely used databases,
most of which have specimens in modern collections. , the ''Meteoritical Bulletin Database'' had 1,180 confirmed falls.
[
]
Falls
Most meteorite falls are collected on the basis of eyewitness accounts of the fireball or the impact of the object on the ground, or both. Therefore, despite the fact that meteorites fall with virtually equal probability everywhere on Earth, verified meteorite falls tend to be concentrated in areas with higher human population densities such as Europe, Japan, and northern India.
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 Přibram 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 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
The Smithsonian Astrophysical Observatory (SAO) is a research institute of the Smithsonian Institution, concentrating on astrophysical studies including galactic and extragalactic astronomy, cosmology, solar, earth and planetary sciences, the ...
from 1963 to 1975 in the midwestern US
The Midwestern United States, also referred to as the Midwest or the American Midwest, is one of four census regions of the United States Census Bureau (also known as "Region 2"). It occupies the northern central part of the United States. I ...
. 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 is an international organization based in Central Europe (Germany and Czech Republic). Its purpose is systematic and simultaneous night observation of meteors and other nebular objects.
Description
The network was initia ...
, a descendant of the original Czech program that recovered Pribram, led to the discovery and orbit calculations for the ''Neuschwanstein
Neuschwanstein Castle (german: Schloss Neuschwanstein, , Southern Bavarian: ''Schloss Neischwanstoa'') is a 19th-century historicist palace on a rugged hill above the village of Hohenschwangau near Füssen in southwest Bavaria, Germany. The p ...
'' meteorite in 2002. NASA has an automated system that detects meteors and calculates the orbit, magnitude, ground track
A ground track or ground trace is the path on the surface of a planet directly below an aircraft's or satellite's trajectory. In the case of satellites, it is also known as a suborbital track, and is the vertical projection of the satellite's or ...
, and other parameters over the southeast USA, which often detects a number of events each night.
Finds
Until the twentieth century, only a few hundred meteorite finds had ever been discovered. More than 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 more than 30,000 meteorite finds in the world's collections started with the discovery by Harvey H. Nininger that meteorites are much more common on the surface of the Earth than was previously thought.
United States
Nininger's strategy was to search for meteorites in the Great Plains
The Great Plains (french: Grandes Plaines), sometimes simply "the Plains", is a broad expanse of flatland in North America. It is located west of the Mississippi River and east of the Rocky Mountains, much of it covered in prairie, steppe, an ...
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 more than 200 new meteorites, mostly stony types.
In the late 1960s, Roosevelt County, New Mexico
Roosevelt County is a List of counties in New Mexico, county located in the U.S. state of New Mexico. As of the 2010 United States Census, 2010 census, the population was 19,846. Its county seat is Portales, New Mexico, Portales. The county was ...
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
In soil science, agriculture and gardening, hardpan or soil pan is 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 ...
layer. During the dustbowl
The Dust Bowl was a period of severe dust storms that greatly damaged the ecology and agriculture of the American and Canadian prairies during the 1930s. The phenomenon was caused by a combination of both natural factors (severe drought) an ...
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. To date, thousands of meteorites have been recovered from the Mojave, Sonoran, Great Basin
The Great Basin is the largest area of contiguous endorheic basin, endorheic watersheds, those with no outlets, in North America. It spans nearly all of Nevada, much of Utah, and portions of California, Idaho, Oregon, Wyoming, and Baja California ...
, and Chihuahuan Desert
The Chihuahuan Desert ( es, Desierto de Chihuahua, ) is a desert ecoregion designation covering parts of northern Mexico and the southwestern United States. It occupies much of far West Texas, the middle to lower Rio Grande Valley and the lower P ...
s, with many being recovered on dry lake
A dry lake bed, also known as a playa, is a basin or depression that formerly contained a standing surface water body, which disappears when evaporation processes exceeds recharge. If the floor of a dry lake is covered by deposits of alkaline c ...
beds. Significant finds include the three-tonne Old Woman meteorite, currently on display at the Desert Discovery Center in Barstow, California
Barstow is a city in San Bernardino County, California, in the Mojave Desert of Southern California. Located in the Inland Empire region of California, the population was 25,415 at the 2020 census. Barstow is an important crossroads for the I ...
, and the Franconia and Gold Basin meteorite strewn fields; hundreds of kilograms of meteorites have been recovered from each. 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. Several of the meteorites found recently are currently on display in the Griffith Observatory
Griffith Observatory is an observatory in Los Angeles, California on the south-facing slope of Mount Hollywood in Griffith Park. It commands a view of the Los Angeles Basin including Downtown Los Angeles to the southeast, Hollywood to the south, ...
in Los Angeles, and at UCLA
The University of California, Los Angeles (UCLA) is a public land-grant research university in Los Angeles, California. UCLA's academic roots were established in 1881 as a teachers college then known as the southern branch of the California St ...
's Meteorite Gallery.
Antarctica
A few meteorites were found in Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...
between 1912 and 1964. In 1969, the 10th Japanese Antarctic Research Expedition found nine meteorites on a blue ice field near the Yamato Mountains. With this discovery, came the realization that movement of ice sheet
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are in Antarctica and Greenland; during the Last Glacial Period at Las ...
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
The Transantarctic Mountains (abbreviated TAM) comprise a mountain range of uplifted (primarily sedimentary rock, sedimentary) rock in Antarctica which extend, with some interruptions, across the continent from Cape Adare in northern Victoria La ...
on the other side of the continent: the Antarctic Search for Meteorites (ANSMET
ANSMET (Antarctic Search for Meteorites) 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 mete ...
) program. 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).
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
The deserts of Australia or the Australian deserts cover about , or 18% of the Australian mainland, but about 35% of the Australian continent receives so little rain, it is practically desert. Collectively known as the Great Australian desert, th ...
. Several dozen meteorites had already been found in the Nullarbor
The Nullarbor Plain ( ; Latin: feminine of , 'no', and , 'tree') is part of the area of flat, almost treeless, arid or semi-arid country of southern Australia, located on the Great Australian Bight coast with the Great Victoria Desert to its ...
region of Western
Western may refer to:
Places
*Western, Nebraska, a village in the US
*Western, New York, a town in the US
*Western Creek, Tasmania, a locality in Australia
*Western Junction, Tasmania, a locality in Australia
*Western world, countries that id ...
and South Australia
South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...
. Systematic searches between about 1971 and the present recovered more than 500 others, ~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 ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
. In the extremely arid climate, there has been relatively little weathering
Weathering is the deterioration of rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms. Weathering occurs ''in situ'' (on site, with little or no movement), ...
or sedimentation
Sedimentation is the deposition of sediments. It takes place when particles in suspension 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 ...
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
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 southeast of Dirj (Daraj), Libya
Libya (; ar, ليبيا, Lībiyā), officially the State of Libya ( ar, دولة ليبيا, Dawlat Lībiyā), is a country in the Maghreb region in North Africa. It is bordered by the Mediterranean Sea to the north, Egypt to Egypt–Libya bo ...
. 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, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in t ...
. 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 or hamada
A hamada ( ar, حمادة, ) is a type of desert landscape consisting of high, largely barren, hard rocky plateaus, where most of the sand has been removed by deflation. The majority of the Sahara is in fact hamada. Other examples are Negev dese ...
s: flat, featureless areas covered only by small pebbles and minor amounts of sand. Dark-colored meteorites can be easily spotted in these places. In the case of several meteorite fields, such as Dar al Gani
The Dar al Gani (also known as DaG) is a meteorite field in the Libyan Sahara. The site is a plateau of limestone, about long and at its widest.
Dark-colored meteorites can be easily spotted in this field, where they have also been well preserv ...
, Dhofar, and others, favorable light-colored geology consisting of basic
BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Thomas E. Kurtz at Dartmouth College ...
rocks (clays, dolomite Dolomite may refer to:
*Dolomite (mineral), a carbonate mineral
*Dolomite (rock), also known as dolostone, a sedimentary carbonate rock
*Dolomite, Alabama, United States, an unincorporated community
*Dolomite, California, United States, an unincor ...
s, and limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
s) makes meteorites particularly easy to identify.
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 scientific method is an empirical method for acquiring knowledge that has characterized the development of science since at least the 17th century (with notable practitioners in previous centuries; see the article history of scientific m ...
. 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.
Northwest Africa
Meteorite markets came into existence in the late 1990s, especially in Morocco
Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...
. This trade was driven by Western commercialization and an increasing number of collectors. The meteorites were supplied 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. When they get classified, they are named "Northwest Africa" (abbreviated NWA) followed by a number. It is generally accepted that NWA meteorites originate in Morocco, Algeria, Western Sahara, Mali, and possibly even further afield. Nearly all of these meteorites leave Africa through Morocco. Scores of important meteorites, including Lunar and Martian ones, have been discovered and made available to science via this route. A few of the more notable meteorites recovered include Tissint
Tissint ( ber, ⵜⵉⵙⵉⵏⵜ, ar, تيسينت, also known as Agadir Tissinnt, Agadir Tissint, or Tissinnt) is a small town near Tata, Morocco in Tata Province in the Souss-Massa region of Morocco. It has a population of 9,927 as of 2004.
...
and Northwest Africa 7034. Tissint was the first witnessed Martian meteorite fall in more than fifty years; NWA 7034 is the oldest meteorite known to come from Mars, and is a unique water-bearing regolith breccia.
Arabian Peninsula
In 1999, meteorite hunters discovered that the desert in southern and central Oman
Oman ( ; ar, عُمَان ' ), officially the Sultanate of Oman ( ar, سلْطنةُ عُمان ), is an Arabian country located in southwestern Asia. It is situated on the southeastern coast of the Arabian Peninsula, and spans the mouth of t ...
were also favorable for the collection of many specimens. The gravel plains in the Dhofar
The Dhofar Governorate ( ar, مُحَافَظَة ظُفَار, Muḥāfaẓat Ẓufār) is the largest of the 11 Governorates in the Sultanate of Oman in terms of area. It lies in Southern Oman, on the eastern border with Yemen's Al Mahrah Gov ...
and Al Wusta regions of Oman, south of the sandy deserts of the Rub' al Khali
The Rub' al KhaliOther standardized transliterations include: / . The ' is the assimilated Arabic definite article, ', which can also be transliterated as '. (; ar, ٱلرُّبْع ٱلْخَالِي (), the "Empty Quarter") is the sand de ...
, had yielded about 5,000 meteorites as of mid-2009. Included among these are a large number of lunar
Lunar most commonly means "of or relating to the Moon".
Lunar may also refer to:
Arts and entertainment
* ''Lunar'' (series), a series of video games
* "Lunar" (song), by David Guetta
* "Lunar", a song by Priestess from the 2009 album ''Prior t ...
and Martian
Mars, the fourth planet from the Sun, has appeared as a setting in works of fiction since at least the mid-1600s. It became the most popular celestial object in fiction in the late 1800s as the Moon was evidently lifeless. At the time, the pred ...
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 {{Refimprove, date=December 2011
An international incident (or diplomatic incident) is a seemingly relatively small or limited action, incident or clash that results in a wider dispute between two or more nation-states. International incidents can ...
, 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.
In human affairs
Meteorites have figured into human culture since their earliest discovery as ceremonial or religious objects, as the subject of writing about events occurring in the sky and as a source of peril. The oldest known iron artifacts are nine small beads hammered from meteoritic iron. They were found in northern Egypt and have been securely dated to 3200 BC.
Ceremonial or religious use
Although the use of the metal found in meteorites is also recorded in myths of many countries and cultures where the celestial source was often acknowledged, scientific documentation only began in the last few centuries.
Meteorite falls may have been the source of cultish worship. The cult in the Temple of Artemis
The Temple of Artemis or Artemision ( gr, Ἀρτεμίσιον; tr, Artemis Tapınağı), also known as the Temple of Diana, was a Greek temple dedicated to an ancient, local form of the goddess Artemis (identified with Diana, a Roman god ...
at Ephesus, one of the Seven Wonders of the Ancient World
The Seven Wonders of the Ancient World, also known as the Seven Wonders of the World or simply the Seven Wonders, is a list of seven notable structures present during classical antiquity. The first known list of seven wonders dates back to the 2 ...
, possibly originated with the observation and recovery of a meteorite that was understood by contemporaries to have fallen to the earth from Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...
, the principal Roman deity. There are reports that a sacred stone was enshrined at the temple that may have been a meteorite.
The Black Stone
The Black Stone ( ar, ٱلْحَجَرُ ٱلْأَسْوَد, ', 'Black Stone') is a rock set into the eastern corner of the Kaaba, the ancient building in the center of the Grand Mosque in Mecca, Saudi Arabia. It is revered by Muslims as an ...
set into the wall of the Kaaba
The Kaaba (, ), also spelled Ka'bah or Kabah, sometimes referred to as al-Kaʿbah al-Musharrafah ( ar, ٱلْكَعْبَة ٱلْمُشَرَّفَة, lit=Honored Ka'bah, links=no, translit=al-Kaʿbah al-Musharrafah), is a building at the c ...
has often been presumed to be a meteorite, but the little available evidence for this is inconclusive.
Some Native Americans treated meteorites as ceremonial objects. In 1915, a iron meteorite was found in a Sinagua
The Sinagua were a pre-Columbian culture that occupied a large area in central Arizona from the Little Colorado River, near Flagstaff, to the Verde River, near Sedona, including the Verde Valley, area around San Francisco Mountain, and signifi ...
(c. 1100–1200 AD) burial cyst near Camp Verde, Arizona
Camp Verde ( yuf-x-yav, ʼMatthi:wa; Western Apache: Gambúdih) is a town in Yavapai County, Arizona, United States. As of the 2010 census, the population of the town is 10,873.
The town hosts an annual corn festival in July, sponsored and or ...
, 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
Pojoaque (; Tewa: Pʼohsųwæ̨geh Ówîngeh/P'osuwaege Owingeh ’òhsũ̀wæ̃̀gè ʔówîŋgè, Po’su wae geh, which translates to “water gathering place”, is a census-designated place (CDP) in Santa Fe County, New Mexico, United States ...
, 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
Meteoric iron, sometimes meteoritic iron, is a native metal and early-universe protoplanetary-disk remnant found in meteorites and made from the elements iron and nickel, mainly in the form of the mineral phases kamacite and taenite. Meteoric iro ...
found in Hopewell burial mounds
A tumulus (plural tumuli) is a mound of Soil, earth and Rock (geology), stones raised over a grave or graves. Tumuli are also known as barrows, burial mounds or ''kurgans'', and may be found throughout much of the world. A cairn, which is a ...
, and the discovery of the Winona meteorite in a Native American stone-walled crypt.
Historical writings
In medieval China during the Song dynasty
The Song dynasty (; ; 960–1279) was an imperial dynasty of China that began in 960 and lasted until 1279. The dynasty was founded by Emperor Taizu of Song following his usurpation of the throne of the Later Zhou. The Song conquered the rest ...
, a meteorite strike event was recorded by Shen Kuo
Shen Kuo (; 1031–1095) or Shen Gua, courtesy name Cunzhong (存中) and pseudonym Mengqi (now usually given as Mengxi) Weng (夢溪翁),Yao (2003), 544. was a Chinese polymathic scientist and statesman of the Song dynasty (960–1279). Shen wa ...
in 1064 AD near Changzhou
Changzhou ( Changzhounese: ''Zaon Tsei'', ) is a prefecture-level city in southern Jiangsu province, China. It was previously known as Yanling, Lanling and Jinling. Located on the southern bank of the Yangtze River, Changzhou borders the provin ...
. He reported "a loud noise that sounded like a thunder was heard in the sky; a giant star, almost like the moon, appeared in the southeast" and later finding the crater and the still-hot meteorite within, nearby.
Two of the oldest recorded meteorite falls in Europe are the Elbogen (1400) and Ensisheim
Ensisheim (; gsw-FR, Anze) is a Communes of France, commune in the Haut-Rhin Departments of France, department in Grand Est in north-eastern France. It is also the birthplace of the composer Léon Boëllmann. The Germanic languages, Germanic et ...
(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
Pallas may refer to:
Astronomy
* 2 Pallas asteroid
** Pallas family, a group of asteroids that includes 2 Pallas
* Pallas (crater), a crater on Earth's moon
Mythology
* Pallas (Giant), a son of Uranus and Gaia, killed and flayed by Athena
* Pa ...
and Others Similar to it, and on Some Associated Natural Phenomena"''. 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
Jean-Baptiste Biot (; ; 21 April 1774 – 3 February 1862) was a French physicist, astronomer, and mathematician who co-discovered the Biot–Savart law of magnetostatics with Félix Savart, established the reality of meteorites, made an early ba ...
and the British chemist, Edward Howard. Biot's study, initiated by the French Academy of Sciences
The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV of France, Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific me ...
, was compelled by a fall of thousands of meteorites on 26 April 1803 from the skies of L'Aigle, France.
Striking people or property
Throughout history, many first- and second-hand reports speak of meteorites killing humans and other animals. One example is from 1490 AD in China, which purportedly killed thousands of people. John Lewis has compiled some of these reports, and summarizes, "No one in recorded history has ever been killed by a meteorite in the presence of a meteoriticist and a medical doctor" and "reviewers who make sweeping negative conclusions usually do not cite any of the primary publications in which the eyewitnesses describe their experiences, and give no evidence of having read them".
Modern reports of meteorite strikes include:
*In 1954 in Sylacauga, Alabama
Sylacauga is a city in Talladega County, Alabama, United States. At the 2020 census, the population was 12,578.
Sylacauga is known for its fine white marble bedrock. This was discovered shortly after settlers moved into the area and has been ...
. A stone chondrite, the Hodges meteorite
The Sylacauga meteorite fell on November 30, 1954, at 12:46 local time (18:46 UT) in Oak Grove, Alabama, near Sylacauga, in the United States. It is also commonly called the Hodges meteorite because a fragment of it struck Ann Elizabeth Fowl ...
or Sylacauga meteorite, crashed through a roof and injured an occupant.
*An approximately fragment of the Mbale meteorite fall from Uganda
}), is a landlocked country in East Africa
East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territor ...
struck a youth, causing no injury.
*In October 2021 a meteorite penetrated the roof of a house in Golden, British Columbia landing on an occupant's bed.
Notable examples
Naming
Meteorites are always named for the places they were found, where practical, 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)). The name designated by the Meteoritical Society is used by scientists, catalogers, and most collectors.
Terrestrial
*Allende meteorite, Allende – largest known carbonaceous chondrite (Chihuahua (state), Chihuahua, Mexico, 1969).
*Allan Hills A81005 – First meteorite determined to be of lunar meteorite, lunar origin.
*ALH84001, Allan Hills 84001 – Mars meteorite that was claimed to prove the existence of life on Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...
.
* The Bacubirito Meteorite (Meteorito de Bacubirito) – A meteorite estimated to weigh .
*Campo del Cielo – a group of iron meteorites associated with a crater field (of the same name) of at least 26 craters in West Chaco Province, Argentina. The total weight of meteorites recovered exceeds 100 tonnes.
*Canyon Diablo meteorite, Canyon Diablo – Associated with Meteor Crater in Arizona.
*Cape York meteorite, Cape York – One of the largest meteorites in the world. A 34-ton fragment called "Ahnighito", is exhibited at the American Museum of Natural History; the largest meteorite on exhibit in any museum.
*Gibeon (meteorite), Gibeon – A large Iron meteorite in Namibia, created the largest known strewn field.
*Hoba meteorite, Hoba – The largest known intact meteorite.
*Kaidun meteorite, Kaidun – An unusual carbonaceous chondrite.
*Mbozi meteorite – A 16-metric-ton ungrouped iron meteorite in Tanzania.
*Murchison meteorite, Murchison – A carbonaceous chondrite found to contain nucleobases – the building block of life.
*Nōgata meteorite, Nōgata – The oldest meteorite whose fall can be dated precisely (to 19 May 861, at Nōgata, Fukuoka, Nōgata)
*Orgueil (meteorite), Orgueil – A famous meteorite due to its especially primitive nature and high presolar grain content.
*Sikhote-Alin Meteorite, Sikhote-Alin – Massive iron meteorite impact event that occurred on 12 February 1947.
*Tucson Ring meteorite, Tucson Ring – Ring shaped meteorite, used by a blacksmith as an anvil, in Tucson AZ. Currently at the Smithsonian.
*Willamette Meteorite, Willamette – The largest meteorite ever found in the United States.
* 2007 Carancas impact event – 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.
* 2013 Russian meteor event – a 17-metre diameter, 10 000 ton asteroid hit the atmosphere above Chelyabinsk, Russia at 18 km/s around 09:20 local time (03:20 UTC) 15 February 2013, producing a very bright superbolide, fireball in the morning sky. A number of small meteorite fragments have since been found nearby.
Extraterrestrial
*Bench Crater meteorite (Apollo 12, 1969) and the Hadley Rille meteorite (Apollo 15, 1971) − Fragments of asteroids were found among the samples collected on the Moon.
*Block Island meteorite and Heat Shield Rock – Discovered on Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...
by Opportunity rover among four other iron meteorites. Two nickel-iron meteorites were identified by the Spirit rover. (See also: Template:MarsRocks, Mars rocks)
Large impact craters
* Acraman crater in South Australia ( diameter)
* Ames crater in Major County, Oklahoma diameter
* Brent crater in northern Ontario ( diameter)
* Chesapeake Bay impact crater ( diameter)
* Chicxulub crater off the coast of Yucatán Peninsula ( diameter)
* Clearwater Lakes a double crater impact in Québec, Canada ( in diameter)
* Lonar crater in India ( diameter)
* Lumparn in Åland, in the Baltic Sea ( diameter)
* Manicouagan Reservoir in Québec, Canada ( diameter)
* Manson crater in Iowa ( crater is buried)
* Meteor Crater in Arizona, also known as "Barringer Crater", the first confirmed terrestrial impact crater. ( diameter)
* Mjølnir impact crater in the Barents Sea ( diameter)
* Nördlinger Ries crater in Bavaria, Germany ( diameter)
* Popigai impact structure in Russia ( diameter)
* Siljan Ring in Sweden, largest crater in Europe ( diameter)
* Sudbury Basin in Ontario, Canada ( diameter).
* Ungava Bay in Québec, Canada ()
* Vredefort impact structure in South Africa, the largest known impact structure on Earth ( diameter from an estimated wide meteorite).
Disintegrating meteoroids
* Tunguska event
The Tunguska event (occasionally also called the Tunguska incident) was an approximately 12-megaton explosion that occurred near the Podkamennaya Tunguska River in Yeniseysk Governorate (now Krasnoyarsk Krai), Russia, on the morning of June 30, ...
in Siberia 1908 (no crater)
* Vitim event in Siberia 2002 (no crater)
* 2013 Russian meteor event, Chelyabinsk event in Russia 2013 (no known crater)
See also
* Atmospheric focusing
*Barringer Medal
* Glossary of meteoritics
* List of impact craters on Earth
* List of Martian meteorites
* List of meteorite minerals
* List of rocks on Mars
* List of possible impact structures on Earth
* Meteor shower
* Meteorite find
* Meteoroid
* Micrometeorite
* Panspermia
References
External links
Current meteorite news articles
The British and Irish Meteorite Society
The Natural History Museum's meteorite catalogue database
Meteoritical Society
Earth Impact Database
Every Recorded Meteorite Impact on Earth
from Tableau Software
Meteor Impact Craters Around the World
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Meteorites,
Geophysics