Meteorite fall statistics
Meteorite fall statistics are frequently used by planetary scientists to approximate the true flux of
- Some meteorite types are easier to find than others.
- Some meteorite types are degraded by weathering more quickly than others.
- Some meteorites, especially iron meteorites, may have been collected by people in the past who recognized them as being unusual and/or useful, thereby removing them from the scientific record.
- Many meteorites fall as showers of many stones, but when they are collected long after the event it may be difficult to tell which ones were part of the same fall.
- Many meteorites are found by people who sell meteorites... valuable, rare types become known to science quickly, while those of low value may never be described.
There have been many attempts to correct statistical analyses of meteorite finds for some of these effects, especially to estimate the frequency with which rare meteorite types fall. For example, there are over 100 known lunar meteorite finds, but none has ever been observed to fall. However, for abundant types, meteorite fall statistics are generally preferred.
These statistics are current through June 9, 2012.
Statistics by material
For most meteorite falls, even those that occurred long ago or for which material has never received complete scientific characterization, it is known whether the object was a stone, stony iron, or iron meteorite. Here are the numbers and percentages of each type, based on literature data.[1][2][3]
Material | Number | % |
---|---|---|
Iron meteorites | 49 | 4.4% |
Stony-iron meteorites | 11 | 1.0% |
Stony meteorites | 1042 | 94.6% |
Total | 1102 | 100.0% |
Statistics by major category
The traditional way of subdividing meteorites (see
Category | Number | % |
---|---|---|
Irons | 49 | 4.6% |
Stony irons | 11 | 1.0% |
Achondrites | 86 | 8.2% |
Chondrites | 915 | 86.2% |
Total | 1062 | 100.0% |
Statistics by meteorite group
Probably the most useful statistical breakdown of meteorite falls is by group, which is the fundamental way that meteorites are classified. About 5% of the meteorites in the table just above have not been sufficiently classified to allow them to be put into such groups. Again, a small adjustment could be made to the percentages to correct for this effect, but it does not greatly change the results. Note that a number of meteorite groups are only represented by a small number of falls; the percentages of falls belonging to these groups have a large uncertainty.
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Grand Total: 1003 meteorites |
Statistics by country
Statistics by continent and time
Epoch | Europe | Asia | North America |
Africa | South America |
Oceania | Total |
---|---|---|---|---|---|---|---|
Pre-1400 | 1 | 1 | 2 | ||||
1400s | 4 | 4 | |||||
1500s | 2 | 2 | |||||
1600s | 9 | 3 | 12 | ||||
1700s | 25 | 3 | 28 | ||||
1800–1820 | 31 | 7 | 3 | 1 | 42 | ||
1821–1840 | 26 | 11 | 9 | 1 | 1 | 48 | |
1841–1860 | 42 | 15 | 12 | 1 | 70 | ||
1861–1880 | 47 | 36 | 14 | 6 | 4 | 1 | 108 |
1881–1900 | 36 | 27 | 20 | 7 | 2 | 92 | |
1901–1920 | 27 | 55 | 21 | 10 | 4 | 2 | 119 |
1921–1940 | 38 | 55 | 32 | 17 | 14 | 5 | 161 |
1941–1960 | 27 | 27 | 18 | 31 | 12 | 3 | 118 |
1961–1980 | 19 | 42 | 22 | 29 | 8 | 3 | 123 |
1981–2000 | 12 | 49 | 19 | 24 | 4 | 2 | 110 |
2001- | 11 | 15 | 12 | 16 | 7 | 2 | 63 |
Total | 357 | 346 | 121 | 144 | 53 | 20 | 1102 |
Notes
- ^ Western Sahara is not a country. It is a disputed territory in the Maghreb region of North Africa, partially controlled by the self-proclaimed Sahrawi Arab Democratic Republic and partially Moroccan-occupied.
See also
References
- ^ "Meteoritical Bulletin Database". Lunar and Planetary Institute. Retrieved August 9, 2018.
- ^ The NHM Catalogue of Meteorites
- ^ MetBase