More than 5,000 tons of extraterrestrial dust fall to Earth each year

More than 5,000 tons of extraterrestrial dust fall to Earth each year
Electron micrograph of a Concordia micrometeorite extracted from snow at Dome C. score: © Cécile Engrand/Jean Duprat

Yearly, our planet encounters mud from comets and asteroids. These interplanetary mud particles cross by our ambiance and provides to capturing stars. A few of them attain the bottom within the type of micrometeorites.

A global program performed for practically 20 years by scientists from the CNRS, the Université Paris-Saclay and the Nationwide museum of pure historical past with the assist of the French institute, has decided that 5,200 tons per yr of those micrometeorites attain the bottom. The research can be accessible within the journal Earth & Planetary Science Letters from April 15.

Micrometeorites have at all times fallen on our planet. These interplanetary mud particles from comets or asteroids are particles of some tenths to hundredths of a millimeter which have handed by the ambiance and reached the Earth’s floor.

To gather and analyze these micrometeorites, six expeditions led by CNRS researcher Jean Duprat have taken place during the last twenty years close to the Franco-Italian Concordia station (Dome C), which is situated 1,100 off the of Adélie Land, within the coronary heart of Antarctica. Dome C is a perfect assortment spot as a result of low accumulation fee of snow and the close to absence of terrestrial mud.

These expeditions have collected sufficient extraterrestrial particles (starting from 30 to 200 micrometers in dimension), to measure their annual flux, which corresponds to the mass accreted on Earth per sq. meter per yr.

If these outcomes are utilized to the entire planet, the annual flux of micrometeorites represents 5,200 tons per yr. That is the primary supply of extraterrestrial matter on our planet, far forward of bigger objects akin to meteorites, for which the flux is lower than ten tons per yr.

More than 5,000 tons of extraterrestrial dust fall to Earth each year
Gathering micrometeorites within the central areas, at Dome C in 2002. Snow sampling. Credit score: © Jean Duprat/ Cécile Engrand/ CNRS Photothèque

A comparability of the flux of micrometeorites with theoretical predictions confirms that almost all micrometeorites most likely come from comets (80%) and the remaining from asteroids.

That is precious data to raised perceive the function performed by these interplanetary mud particles in supplying water and carbonaceous molecules on the younger Earth.

An city assortment of modern-day micrometeorites

Extra data:
J. Rojas et al. The micrometeorite flux at Dome C (Antarctica), monitoring the accretion of extraterrestrial mud on Earth, Earth and Planetary Science Letters (2021). DOI: 10.1016/j.epsl.2021.116794

Greater than 5,000 tons of extraterrestrial mud fall to Earth every year (2021, April 8)
retrieved Eight April 2021

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