Every year the Earth’s surface reaches more than 5 thousand tons of interplanetary dust particles ranging in size from hundredths to several tenths of a millimeter.
It is difficult to detect cosmic dust on a blue planet, as it is quickly washed away by earth’s precipitation in the form of rain and snow, so Jean Duprat, a physicist from the French National Center for Scientific Research, and his colleagues made six expeditions to Antarctica to study precipitation.
The results of the current work came from data collected over 20 years of work. It studied micrometeorites – these are particles that previously belonged to comets and asteroids, with a size of 30 to 200 microns, and fell on the surface of our planet from space.
Over the course of their work, scientists have discovered 1,280 micrometeorites less than 0.7 mm in size and 808 fused dust clumps weighing less than 0.35 grams. Dense and solid particles originate from meteorites, which are debris of rock, while loose and porous particles are emitted from comets, which are composed of ice and mud. The latter account for 80% of all cosmic dust falling to Earth, which is consistent with previous estimates.
As a result, scientists discovered that 5,200 tons of cosmic matter falls to the Earth every year. Of these, approximately 1,600 tons of micrometeorites and 3,600 tons of space spherules.
This work, the authors believe, provides a better understanding of the role of interplanetary dust particles in supplying the young Earth with water and carbon molecules.