Meteorite fall statistics

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Template:Short description Meteorite fall statistics are frequently used by planetary scientists to approximate the true flux of meteorites on 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 30 times as much finds than falls, their raw distribution of types does not accurately reflect what falls to Earth. The reasons for this include the following:

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

Material Number %
Iron meteorites 49 2%[5]
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 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 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.

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 2 0.2%
IIF 1 0.1%
IIG 0 0.0%
IIIAB 11 1.1%
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 34 3.4%
Howardite 16 1.6%
Brachinite 0 0.0%
Ureilite 6 0.6%
Winonaite 1 0.1%
Ungrouped 2 0.2%
Lunar 0 0.0%
Martian 5 0.5%
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 15 1.5%
CO 6 0.6%
CR 2 0.2%
CV 7 0.7%
C ungrouped 6 0.6%
EH 8 0.8% Enstatite:
1.6%
EL 8 0.8%
H 339 33.8% Ordinary:
80.0%
H/L 1 0.1%
L 371 37.0%
L/LL 9 0.9%
LL 82 8.2%
R 1 0.1% Other:
0.2%
K 1 0.1%
Grand Total: 1003 meteorites

Statistics by country

Country N
File:Flag of the Taliban.svg Afghanistan 2
File:Flag of Algeria.svg Algeria 7
File:Flag of Angola.svg Angola 3
File:Flag of Argentina.svg Argentina 24
File:Flag of Armenia.svg Armenia 2
File:Flag of Australia (converted).svg Australia 16
File:Flag of Austria.svg Austria 4
File:Flag of Azerbaijan.svg Azerbaijan 2
File:Flag of Bangladesh.svg Bangladesh 8
File:Flag of Belarus.svg Belarus 3
File:Flag of Belgium (civil).svg Belgium 3
File:Flag of Bosnia and Herzegovina.svg Bosnia and Herzegovina 1
File:Flag of Brazil.svg Brazil 22
File:Flag of Bulgaria.svg Bulgaria 6
File:Flag of Burkina Faso.svg Burkina Faso 8
File:Flag of Myanmar.svg Burma 3
File:Flag of Cambodia.svg Cambodia 2
File:Flag of Cameroon.svg Cameroon 3
File:Flag of Canada (Pantone).svg Canada 16
File:Flag of the Central African Republic.svg Central African Republic 1
File:Flag of Chad.svg Chad 1
File:Flag of Chile.svg Chile 1
File:Flag of the People's Republic of China.svg People's Republic of China 58
File:Flag of Colombia.svg Colombia 1
File:Flag of Costa Rica.svg Costa Rica 1
File:Flag of Croatia.svg Croatia 4
File:Flag of the Czech Republic.svg Czech Republic 15
Country N
Template:Country data DR Congo 5
File:Flag of Denmark.svg Denmark 4
File:Flag of Ecuador.svg Ecuador 1
File:Flag of Egypt.svg Egypt 2
File:Flag of Estonia.svg Estonia 3
File:Flag of Ethiopia.svg Ethiopia 5
File:Flag of Finland.svg Finland 5
File:Flag of France.svg France 63
File:Flag of Germany.svg Germany 32
File:Flag of Ghana.svg Ghana 1
File:Flag of Greece.svg Greece 1
File:Flag of Hungary.svg Hungary 6
File:Flag of India.svg India 127
File:Flag of Indonesia.svg Indonesia 16
File:Flag of Iran.svg Iran 2
File:Flag of Iraq.svg Iraq 2
File:Flag of Ireland.svg Ireland 6
File:Flag of Italy.svg Italy 31
File:Flag of Japan.svg Japan 42
File:Flag of Jordan.svg Jordan 1
File:Flag of Kazakhstan.svg Kazakhstan 6
File:Flag of Kenya.svg Kenya 4
File:Flag of Latvia.svg Latvia 4
File:Flag of Lebanon.svg Lebanon 1
File:Flag of Lesotho.svg Lesotho 1
File:Flag of Libya.svg Libya 1
File:Flag of Lithuania.svg Lithuania 4
File:Flag of Madagascar.svg Madagascar 1
Country N
File:Flag of Malawi.svg Malawi 5
File:Flag of Mali.svg Mali 2
File:Flag of Mauritania.svg Mauritania 3
File:Flag of Mauritius.svg Mauritius 1
File:Flag of Mexico.svg Mexico 19
File:Flag of Mongolia.svg Mongolia 4
File:Flag of Morocco.svg Morocco 6
File:Flag of Namibia.svg Namibia 2
File:Flag of the Netherlands.svg Netherlands 4
File:Flags of New Caledonia.svg New Caledonia 1
File:Flag of New Zealand.svg New Zealand 1
File:Flag of Niger.svg Niger 9
File:Flag of Nigeria.svg Nigeria 14
File:Flag of Norway.svg Norway 9
File:Flag of Pakistan.svg Pakistan 15
File:Flag of Papua New Guinea.svg Papua New Guinea 2
File:Flag of Paraguay.svg Paraguay 1
File:Flag of Peru.svg Peru 1
File:Flag of the Philippines.svg Philippines 4
File:Flag of Poland.svg Poland 11
File:Flag of Portugal.svg Portugal 6
File:Flag of Romania.svg Romania 7
File:Flag of Russia.svg Russia 47
File:Flag of Rwanda.svg Rwanda 1
File:Flag of Saudi Arabia.svg Saudi Arabia 4
File:Flag of Serbia.svg Serbia 4
File:Flag of Slovakia.svg Slovakia 3
Country N
File:Flag of Slovenia.svg Slovenia 5
File:Flag of Somalia.svg Somalia 2
File:Flag of South Africa.svg South Africa 21
File:Flag of South Korea.svg South Korea 3
File:Flag of South Sudan.svg South Sudan 3
File:Flag of Spain.svg Spain 23
File:Flag of Sri Lanka.svg Sri Lanka 1
File:Flag of Sudan.svg Sudan 7
Template:Country data Swaziland 1
File:Flag of Sweden.svg Sweden 9
File:Flag of Switzerland (Pantone).svg  Switzerland 4
File:Flag of the Syrian revolution.svg Syria 1
File:Flag of Tanzania.svg Tanzania 8
File:Flag of Thailand.svg Thailand 3
File:Flag of Tunisia.svg Tunisia 5
File:Flag of Turkey.svg Turkey 12
File:Flag of Turkmenistan.svg Turkmenistan 2
File:Flag of Uganda.svg Uganda 5
File:Flag of Ukraine.svg Ukraine 32
File:Flag of the United Kingdom.svg United Kingdom 18
File:Flag of the United States.svg United States 146
File:Flag of Uzbekistan.svg Uzbekistan 2
File:Flag of Venezuela.svg Venezuela 2
File:Flag of Vietnam.svg Vietnam 3
Western SaharaTemplate:Efn 3
File:Flag of Yemen.svg Yemen 2
File:Flag of Zambia.svg Zambia 1
File:Flag of Zimbabwe.svg Zimbabwe 2
Grand Total: 1106 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 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

Template:Notelist

See also

References

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  3. The NHM Catalogue of Meteorites
  4. MetBase
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