some meteorite statistics

Nearly all meteorites are found in deserts (yes, Antarctica is a desert because the annual precipitation rate is very low). Deserts are places that collect meteorites over thousands of years and nothing much happens to the meteorite. Also, meteorites are easier to find in deserts then they are in places with lots of vegetation or other rocks.

Meteorites are found in Antarctica by government funded expeditions, mainly form the U.S. and Japan. Nearly all have been found since 1976. Many meteorites have been found in the Sahara Desert of northern Africa, mainly by private collectors. More meteorites have been found in Oman, a desert country about the size of New Mexico, than in all of North America (Canada, Mexico, U.S.). Nearly all of the meteorites from Oman have been found since 2000.


Only a small fraction of meteorites are observed to fall, 2.8% for the whole world. The proportion of meteorites that are falls from North America is larger than that for the whole world because most meteorites come from the deserts of Antarctica and Africa, places where meteorites are rarely observed to fall. Also, nearly all meteorites found in deserts fell long before humans actively sought them.


Most meteorites that fall on Earth are stony meteorites. Only a few percent are irons. However, in populated places like North America, people find a greater fraction of the irons because irons tend to be bigger* and are more likely to catch peoples' attention.

*Although only 2.6% of meteorites are irons, 85% of the mass of all meteorites is in the irons. 11% of the mass is in the stony meteorites.


Most stony meteorites are chondrites, and most chondrites are ordinary chondrites. Chondrites contain iron-nickel metal, which is what makes them attracted to a magnet. Most other meteorite types have little metal. The achondrites resemble Earth rocks more closely than the other meteorite types. The proportion of achondrites among stony meteorites may be less than the 4.6% indicated here because among the 20% of meteorites that have been found in Africa and Oman (above), collectors have not reported all of the ordinary chondrites but most of the achondrites have been reported because they sell for higher prices.

All data presented here was gleaned from the Meteoritical Bulletin Database of The Meteoritical Society. See also Wikipedia's "Meteorite fall statistics."

 


Prepared by
: Randy L. Korotev
  
Department of Earth and Planetary Sciences
Washington University in St. Louis

  
Please don’t contact me about the meteorite
you think you've found until you read this and this
.

e-mail
korotev@wustl.edu

Last revised05-Apr-2013

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