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 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 40 or so 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 April 2007.

Contents

Statistics by material

Statistics by major category

Statistics by meteorite group

Statistics by Country

Statistics by Continent and Time

References

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	48	4.6%
Stony-iron meteorites	11	1.0%
Stony meteorites	999	94.4%
Total	1058	100.0%

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.

Category	Number	%
Irons	48	4.7%
Stony irons	11	1.1%
Achondrites	81	8.0%
Chondrites	876	86.2%
Total	1016	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.

Group N % 'Iron meteorites' IAB complex 10 1.0% IC 0 0.0% IIAB 6 0.6% IIC 0 0.0% IID 3 0.3% IIE 1 0.1% IIF 1 0.1% IIG 0 0.0% IIIAB 11 1.2% IIIE 0 0.0% IIIF 0 0.0% IVA 4 0.4% IVB 0 0.0% Ungrouped 4 0.4% 'Stony Iron meteorites' Mesosiderite 7 0.7% Pallasite 4 0.4%	Group N % 'Achondrites' Acapulcoite 1 0.1% Lodranite 1 0.1% Angrite 1 0.1% Aubrite 9 0.9% Diogenite 11 1.2% Eucrite 31 3.2% Howardite 16 1.7% Brachinite 0 0.0% Ureilite 5 0.5% Winonaite 1 0.1% Ungrouped 1 0.1% Lunar 0 0.0% Martian 4 0.4%	Group N % Class total 'Chondrites' CB 1 0.1% Carbonaceous: 4.4% CH 0 0.0% CI 5 0.5% CK 2 0.2% CM 14 1.5% CO 6 0.6% CR 2 0.2% CV 7 0.7% C ungrouped 5 0.5% EH 8 0.8% Enstatite: 1.7% EL 8 0.8% H 323 33.8% Ordinary: 79.9% L 355 37.1% L/LL 9 0.9% LL 78 8.2% R 1 0.1% Other: 0.2% K 1 0.1%
Grand Total: 957 meteorites

Statistics by Country

Country N Afghanistan 1 Algeria 7 Angola 3 Argentina 22 Armenia 2 Australia 14 Austria 4 Azerbaijan 2 Bangladesh 8 Belarus 3 Belgium 3 Bosnia and Herzegovina 1 Brazil 21 Bulgaria 5 Burkina Faso 8 Burma 3 Cambodia 2 Cameroon 3 Canada 14 Central African Republic 1 Chad 1 Chile 1 China 56 Congo - Dem. Rep. 5 Costa Rica 1 Croatia 4 Czech Republic 15	Country N Denmark 3 Egypt 2 Estonia 3 Ethiopia 5 Finland 5 France 63 Germany 32 Ghana 1 Greece 1 Hungary 5 India 122 Indonesia 16 Iran 2 Iraq 2 Ireland 6 Italy 31 Japan 42 Jordan 1 Kazakhstan 6 Kenya 3 Latvia 4 Lebanon 1 Lesotho 1 Lithuania 4 Madagascar 1 Malawi 5	Country N Mali 1 Mauritania 2 Mauritius 1 Mexico 17 Mongolia 4 Morocco 4 Namibia 2 Netherlands 4 New Caledonia 1 New Zealand 1 Niger 9 Nigeria 13 Norway 9 Pakistan 15 Papua New Guinea 2 Paraguay 1 Philippines 4 Poland 10 Portugal 6 Romania 7 Russia 47 Rwanda 1 Saudi Arabia 4 Serbia 4 Slovakia 2 Slovenia 1 Somalia 2	Country N South Africa 21 South Korea 3 Spain 22 Sri Lanka 1 Sudan 9 Swaziland 1 Sweden 9 Switzerland 4 Syria 1 Tanzania 8 Thailand 3 Tunisia 5 Turkey 10 Turkmenistan 2 Uganda 5 Ukraine 32 United Kingdom 18 United States 138 Uzbekistan 2 Venezuela 2 Vietnam 3 Western Sahara 3 Yemen 2 Zambia 1 Zimbabwe 2
Grand Total: 1058 meteorites

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	46	36	14	6	4	1	107
1881-1900	36	27	20	7		2	92
1901-1920	26	55	21	10	4	2	118
1921-1940	38	55	32	17	14	5	161
1941-1960	27	26	18	31	12	3	117
1961-1980	19	42	20	29	8	3	121
1981-2000	12	49	18	23	4	2	108
2001-	5	7	3	10			25
Total	349	337	170	136	47	18	1057

References

1. Meteoritical Bulletin Database
2. The NHM Catalogue of Meteorites
3. MetBase