5,200 tonnes of space dust fall to Earth each year. The space between the planets is sprinkled with dust particles, called cosmic dust. These interplanetary dust particles pass through our atmosphere and reach the Earth’s surface in the form of micrometeorites. Micrometeorites from comets or asteroids are particles of a few tenths to hundredths of a millimetre and are the biggest source of extraterrestrial material delivered to Earth’s surface.
To collect and analyse these micrometeorites, six expeditions led by CNRS researcher Jean Duprat have taken place over the last two decades near the Franco-Italian Concordia station (Dome C), which is located 1,100 kilometres off the coast of Adélie Land, in the heart of Antarctica. Dome C is an ideal collection spot due to the low accumulation rate of snow and the near absence of terrestrial dust.
These expeditions have collected enough extraterrestrial particles (ranging from 30 to 200 micrometres in size), to measure their annual flux, which corresponds to the mass accreted on Earth per square metre per year.
If these results are applied to the whole planet, the total annual flux of micrometeorites represents 5,200 tons per year. This is the main source of extraterrestrial matter on our planet, far ahead of larger objects such as meteorites, for which the flux is less than ten tons per year.
Picture Credit : Google
