Micrometeorite

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Micrometeorite from the Antarctic snow

Micrometeorites (also ... meteorites ) are tiny meteorites with a size of typically a few hundred micrometers to a few millimeters. Micrometeorites are closely related to interplanetary dust . When they enter the earth's atmosphere, they typically have speeds of 11 to 72 km / s.

About 95% of the interplanetary material falling on Earth consists of micrometeorites. Mineralogically and in chemical composition most micrometeorites resemble carbonaceous chondrites and only relatively few resemble ordinary chondrites ; with macroscopic meteorites it is the other way round.

If micrometeorites mainly originate from the asteroid belt , but this is not certain, they probably represent the frequency of the different types of asteroids in the asteroid belt better than macroscopic meteorites. The origin of the micrometeorites from comets is also discussed.

See also

literature

  • Eva Ahnert-Rohlfs : Preliminary communication on experiments to detect meteoritic dust . Communication from the Sonneberg 45 observatory, 1954
  • Michel Maurette: Micrometeorites and the mysteries of our origins. Springer, Berlin 2006, ISBN 978-3-540-25816-2 .
  • MJ Genge, et al .: The classification of micrometeorites. Meteoritics & Planetary Science, Volume 43, Issue 3, pp. 497-515, 2008, pdf
  • MJ Genge, et al .: An urban collection of modern-day large micrometeorites: Evidence for variations in the extraterrestrial dust flux through the Quaternary . Geology (2017) 45 (2): 119-122, doi : 10.1130 / G38352.1
  • Jon Larsen : In Search of Stardust: Amazing Micrometeorites and Their Terrestrial Imposters. Voyageur Press, Minneapolis 2017, ISBN 0-7603-5264-X .
  • Jon Larsen: Starfighter: my search for the stuff the universe is made of. Benevento, Munich 2019, ISBN 978-3-7109-0085-3 .

Web links

Individual evidence

  1. ^ Donald E. Brownlee: Cosmic Dust: Building Blocks of Planets Falling from the Sky . June 2016.