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[[Image:Leonid meteor shower as seen from space (1997).jpg|thumb|250px|meteors falling to Earth]]
A '''meteor''' is what you see when a space rock falls to [[Earth]]. It is often known as a '''shooting star''' or '''falling star''' and can be a bright light in the [[night|night]] [[sky]], though most are faint. A few survive long enough to hit the ground. That is called a '''meteorite''', and a large one sometimes leaves a hole in the ground called a [[crater]]. 

A rock that has not yet hit the [[atmosphere]] is called a '''meteoroid'''. Meteoroids may range in size from large pieces of rock to tiny dust particles floating in space that did not form [[planet]]s. When the meteoroids enter Earth's [[atmosphere]] they are usually going faster than the Earth's [[escape velocity]] of 13&nbsp;km/s or [[Mach number|Mach 40]]. This makes them heat up and usually break apart. When the heat makes them glow, they are known as meteors.

Meteors are distinct from [[comet]]s or [[asteroid]]s, but some, especially those associated with [[meteor shower]]s, are dust particles that came out of comets.

There are several types of meteorites including: stony, carbonaceous chondrites, and iron-nickel. Stony meteorites are named because they are largely made up of stone-like mineral material. Carbonaceous chondrites have a high carbon content. Iron-nickel meteorites are mostly iron often with significant nickel as well.

Meteorites happened often during the [[Late Heavy Bombardment]]. Nowadays they sometimes hurt people and property. The [[2013 Russian meteor event]] did the most damage. Large meteorite strikes may have played a part in several of the mass [[extinction]]s, and so indirectly on the course of [[evolution]]. (see [[K/T extinction event]]; [[List of extinction events]]; [[Chicxulub crater]])
== Meteorite types ==

== Chondrites ==
[[File:NWA869Meteorite.jpg|thumb|right|A specimen of the NWA 869 chondrite (type L4-6), showing chondrules and metal flakes]]

Chondrites are stony (non-metallic) [[meteorite]]s that are as old as the [[Solar System]]: 4.55 [[1,000,000,000|billion]] years.<ref>The use of the term non-metallic does not imply the total absence of metals.</ref> They sometimes contain [[amino acids]] and other organic molecules.

They have not been modified due to [[melting]] or other disturbances. They are formed when various types of dust and small grains that were present in the early solar system accreted to form primitive [[asteroid]]s. They are the most common type of meteorite that falls to Earth: they are about 85 or 86 percent of all meteorites.<ref>{{cite journal |title=Meteorites for the Sahara: find locations, shock classification, degree of weathering and pairing |journal=Meteoritics |issn=0026-1114 |volume=30 |issue=1 |pages=113–122 |bibcode=1995Metic..30..113B |last1=Bischoff |first1=A. |last2=Geiger |first2=T. |year=1995 |doi=10.1111/j.1945-5100.1995.tb01219.x}}</ref> 

Their study gives clues about the origin and age of the [[Solar System]], the synthesis of [[organic compound]]s, the [[Abiogenesis|origin of life]] or the presence of water on [[Earth]]. Chondrites can be differentiated from iron meteorites by their low [[iron]] and [[nickel]] content.
[[File:Murnpeowie meteorite.jpg|thumb|Murnpeowie meteorite, an iron meteorite]]
== Carbonaceous chondrites ==
In 2021, a meteorite crashed on the [[Gloucestershire]] town of [[Winchcombe]]. It contained water that was a near-perfect match for that on Earth. The meteorite was picked up soon after it landed.<ref>Amos, Jonathan 2022. Winchcombe meteorite bolsters Earth water theory. [https://www.bbc.co.uk/news/science-environment-63631563]</ref> This is a suggested source for the water on Earth.
== Achondrites ==
About 8 percent of meteorites show signs of melting and recrystallizing. They look rather like [[basalt]] or [[granite]].
== Iron meteorites ==
[[File:Esquel.jpg|thumb|right|A slice of the Esquel meteorite showing the mixture of meteoric iron and silicates that is typical of stony-iron siderolites]]

Iron meteorites are meteorites made of an [[iron]]–[[nickel]] [[alloy]]. They are about 6 percent of all meteorites. This comes from the inner cores of early small proto-planets.<ref name="Weisberg 2006">{{cite book|editor=D.S. Lauretta & H.Y. McSween, Jr.|title=Meteorites and the early Solar System II|year=2006|publisher=University of Arizona Press|location=Tucson|isbn=978-0816525621|url=http://haroldconnolly.com/EES%20716%20Fall%2009%20Reading/Lecture%201/Background%20reading/Weisberg_etal_MESSII.pdf|author=M.K. Weisberg|author2=T. J. McCoy & A.N. Krot|accessdate=2012-01-01|pages=19–52|chapter=Systematics and evaluation of meteorite classification|archive-date=2017-08-08|archive-url=https://web.archive.org/web/20170808001147/http://haroldconnolly.com/EES%20716%20Fall%2009%20Reading/Lecture%201/Background%20reading/Weisberg_etal_MESSII.pdf|url-status=dead}}</ref>  The iron found in iron meteorites was one of the earliest sources of usable iron, before [[human]]s invented [[smelting]]. That signalled the beginning of the [[iron age]].  Iron meteorites are easily found, because they are very different from Earth rocks.
== Siderolites ==
Siderolites are stony-iron meteorites that have almost equal parts of iron and [[silicate]]s. They are quite rare: only about 1 percent of all meteorites are siderolites.

== Meteor Media ==
<gallery widths='160px' heights='100%' mode='traditional' caption=''>
File:Cosmic Fireball Falling Over ALMA.jpg|Meteor seen from the site of the [[Atacama Large Millimeter Array]] (ALMA)

File:Взрыв метеорита над Челябинском 15 02 2013 avi-iCawTYPtehk.webm|Camera recording of a [[Chelyabinsk meteor|superbolide]] passage above [[Chelyabinsk Oblast]], Russia on 15th February 2013. The object in this video is estimated to be {{Measurement converter|17 to 20|m|ft}} in diameter before atmospheric entry.

File:P10220XX.01.49.MESZ.14.08.2019.Berlin.Perseiden.x1.0.gif|A meteoroid of the [[Perseids]] with a size of about {{Convert|1|cm|in|abbr=on|sp=us|frac=8}} entering the earth's atmosphere in real time. The meteoroid is at the bright head of the trail, and the ionisation of the [[mesosphere]] is still visible in the tail.

File:Leonid Meteor.jpg|A meteor of the [[Leonid meteor shower]]; the photograph shows the meteor, afterglow, and wake as distinct components

File:Meteor burst.jpg|Multiple meteors photographed over an extended [[exposure time]] during a [[meteor shower]]

File:PSM V18 D201 Shower of perseids sept 6 and 7.jpg|[[Meteor shower]] on chart

File:SmallAsteroidImpacts-Frequency-Bolide-20141114.jpg|World map of large meteoric events ''(also see [[#Fireball|Fireball]] below)''&nbsp;

File:Fireball Flies Above Gemini North (iotw2602a).tiff|Fireball over [[Maunakea]], Hawai{{okina}}i, near [[Gemini Observatory|Gemini North]]

File:Orionid meteor.jpg|[[Orionids|Orionid]] meteor

File:Meteor Bolide.JPG|Sporadic bolide over the desert of Central Australia and a [[Lyrids|Lyrid]] (top edge)
</gallery>
== Related pages ==
*[[Meteor burst communication]]
*[[Panspermia]]
*[[Meteor shower]]
== References ==
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{{Meteorites}}
{{Solar System}}


[[Category:Meteorites| ]]