Meteorite fall statistics

Meteorite fall statistics are frequently used by planetary scientists to approximate the true flux of meteorites on the Earth. Meteorite falls are those meteorites that are collected soon after being witnessed to fall, whereas meteorite finds are discovered at a later time. Although there are 30x more finds than falls, their raw distribution of types does not accurately reflect what falls to Earth. The reasons for this include:

  1. Some meteorite types are easier to find than others
  2. Some meteorite types are degraded by weathering more quickly than others
  3. 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
  4. 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
  5. 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]

MaterialNumber%
Iron meteorites494.4%
Stony-iron meteorites111.0%
Stony meteorites104294.6%
Total1102100.0%

Statistics by major category

The traditional way of subdividing meteorites (see Meteorites classification) is into irons, stony-irons, and two major groups of stony meteorites, chondrites and achondrites. For some of the less-studied stony meteorite falls, it is not known whether the object is chondritic; thus the number of meteorites that can be so grouped is 4% lower than shown above. These numbers are shown in the next table. One could make a slight correction for the undercounting of stony meteorites (e.g., the percentage of irons would decrease by a 0.2%), but this was not done.

CategoryNumber%
Irons494.6%
Stony irons111.0%
Achondrites868.2%
Chondrites91586.2%
Total1062100.0%

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.

GroupN%
Iron meteorites
IAB complex101.0%
IC00.0%
IIAB60.6%
IIC00.0%
IID30.3%
IIE20.2%
IIF10.1%
IIG00.0%
IIIAB111.1%
IIIE00.0%
IIIF00.0%
IVA40.4%
IVB00.0%
Ungrouped40.4%
Stony Iron meteorites
Mesosiderite70.7%
Pallasite40.4%
GroupN%
Achondrites
Acapulcoite10.1%
Lodranite10.1%
Angrite10.1%
Aubrite90.9%
Diogenite111.2%
Eucrite343.4%
Howardite161.6%
Brachinite00.0%
Ureilite60.6%
Winonaite10.1%
Ungrouped20.2%
Lunar00.0%
Martian50.5%
GroupN%Class total
Chondrites
CB10.1% Carbonaceous:
4.4%
CH00.0%
CI50.5%
CK20.2%
CM151.5%
CO60.6%
CR20.2%
CV70.7%
C ungrouped60.6%
EH80.8% Enstatite:
1.6%
EL80.8%
H33933.8% Ordinary:
80.0%
H/L10.1%
L37137.0%
L/LL90.9%
LL828.2%
R10.1% Other:
0.2%
K10.1%
Grand Total: 1003 meteorites

Statistics by country

CountryN
Afghanistan1
Algeria7
Angola3
Argentina24
Armenia2
Australia16
Austria4
Azerbaijan2
Bangladesh8
Belarus3
Belgium3
Bosnia and Herzegovina1
Brazil22
Bulgaria6
Burkina Faso8
Burma3
Cambodia2
Cameroon3
Canada16
Central African Republic1
Chad1
Chile1
China58
Colombia1
Congo - Dem. Rep.5
Costa Rica1
Croatia4
CountryN
Czech Republic15
Denmark4
Ecuador1
Egypt2
Estonia3
Ethiopia5
Finland5
France63
Germany32
Ghana1
Greece1
Hungary6
India127
Indonesia16
Iran2
Iraq2
Ireland6
Italy31
Japan42
Jordan1
Kazakhstan6
Kenya4
Latvia4
Lebanon1
Lesotho1
Libya1
Lithuania4
Madagascar1
CountryN
Malawi5
Mali2
Mauritania3
Mauritius1
Mexico19
Mongolia4
Morocco6
Namibia2
Netherlands4
New Caledonia1
New Zealand1
Niger9
Nigeria14
Norway9
Pakistan15
Papua New Guinea2
Paraguay1
Peru1
Philippines4
Poland11
Portugal6
Romania7
Russia47
Rwanda1
Saudi Arabia4
Serbia4
Slovakia3
CountryN
Slovenia2
Somalia2
South Africa21
South Korea3
South Sudan3
Spain23
Sri Lanka1
Sudan7
Swaziland1
Sweden9
Switzerland4
Syria1
Tanzania8
Thailand3
Tunisia5
Turkey12
Turkmenistan2
Uganda5
Ukraine32
United Kingdom18
United States146
Uzbekistan2
Venezuela2
Vietnam3
Western Sahara3
Yemen2
Zambia1
Zimbabwe2
Grand Total: 1103 meteorites

Statistics by continent and time

EpochEuropeAsiaNorth
America
AfricaSouth
America
OceaniaTotal
Pre-1400112
1400s44
1500s22
1600s9312
1700s25328
1800–18203173142
1821–1840261191148
1841–1860421512170
1861–1880473614641108
1881–19003627207292
1901–19202755211042119
1921–194038553217145161
1941–196027271831123118
1961–19801942222983123
1981–20001249192442110
2001-111512167263
Total35734612114453201102

See also

References

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