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

Yearly, our planet encounters mud from comets and asteroids. These interplanetary mud particles cross by our ambiance and provides rise 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 polar 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 kilometers off the coast 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 full 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.

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.