Lunar meteorite
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A Lunar meteorite is a meteorite that is known to have originated on the Moon.
The first lunar meteorite, Yamato 791197, was discovered in 1979 in Antarctica; but at that time its origins were unknown. The first meteorite of definite lunar origin was Allan Hills 81005 which was found in 1981 [1]. Meanwhile more than two dozen other different meteorites from the Moon are known. Lunar origin may be established by comparing the mineralogy, the chemical composition, and the isotopic composition between meteorites and samples from the Moon collected by Apollo missions.
Lunar meteorites are launched from the Moon by large impacts. Until the discovery of Sayh al Uhaymir, no single crater could be identified as the origin of lunar meteorites.
For statistical reasons, the composition of lunar meteorites is closer to the average composition of the lunar surface material than the composition of the samples from Apollo and Luna missions. Apollo and Luna samples are from a relatively small area on the nearside of the Moon, whereas lunar meteorites possibly also samples material from the farside of the Moon.
When the first meteorite from moon was discovered in 1982 this led to new speculations that there could also exist meteorites from Mars. In fact, the first Martian meteorite was identified in the same year. There are also speculations about the possibility of finding "Earth meteorites" on the surface of the Moon. This would be very interesting because in this case stones from earth older than 3.9 billion years, which are destroyed on earth by various geological processes, may have survived on the Moon. Thus some scientists propose new missions to the Moon to search for ancient rocks from Earth.
Reference
- [1] Warren P. H., Taylor G. J., Keil K. (1983) Regolith breccia Allan Hills A81005: Evidence of lunar origin and petrography of pristine and nonpristine clasts, Geophys. Res. Lett. 10, 779-782.
See also List of Lunar meteorites
External links
- Lunar Meteorites, Washington Univ. St.Louis (http://epsc.wustl.edu/admin/resources/moon_meteorites.html)
- Lunar Meteorites, Univ. of Arizona (http://www.lpl.arizona.edu/SIC/moon/lunar_meteorites/)
- List of Lunar Meteorites (http://epsc.wustl.edu/admin/resources/meteorites/moon_meteorites_list.html)