micrometeorite
Sign in to saveA micrometeorite is a micrometeoroid that has survived entry through the Earth's atmosphere. Usually found on Earth's surface, micrometeorites differ from meteorites in that they are smaller in size, more abundant, and different in composition. The IAU officially defines meteoroids as 30 micrometers to 1 meter; micrometeorites are the small end of the range (~submillimeter). They are a subset of cosmic dust, which also includes the smaller interplanetary dust particles (IDPs).
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- Micrometeorite
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- Micrometerorite collected from the Antarctic snow.
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~11 min read
Article
14 sectionsContents
- Introduction
- Collection sites
- Ocean sediments
- Terrestrial sediments
- Urban micrometeorites
- Polar depositions
- Classification and origins of micrometeorites
- Classification
- Comet versus asteroid origin of micrometeorites
- Extraterrestrial micrometeorites
- See also
- References
- Further reading
- External links
A micrometeorite is a micrometeoroid that has survived entry through the Earth's atmosphere. Usually found on Earth's surface, micrometeorites differ from meteorites in that they are smaller in size, more abundant, and different in composition. The IAU officially defines meteoroids as 30 micrometers to 1 meter; micrometeorites are the small end of the range (~submillimeter). They are a subset of cosmic dust, which also includes the smaller interplanetary dust particles (IDPs).
Micrometeorites enter Earth's atmosphere at high velocities (at least 11 km/s) and undergo heating through atmospheric friction and compression. Micrometeorites individually weigh between 10−9 and 10−4 g and collectively comprise most of the extraterrestrial material that has come to the present-day Earth.