Every year, our planet encounters dust from comets and asteroids. These interplanetary dust particles pass through our atmosphere and give rise to shooting stars. Some of them reach the ground in the form of micrometeorites. An international program conducted for nearly 20 years by scientists has determined that 5,200 tons per year of these micrometeorites reach the ground.
Micrometeorites have always fallen on our planet. These interplanetary dust particles from comets or asteroids are particles of a few tenths to hundredths of a millimetre that have passed through the atmosphere and reached the Earth's surface.
A comparison of the flux of micrometeorites with theoretical predictions confirms that most micrometeorites probably come from comets (80%) and the rest from asteroids.
This is valuable information to better understand the role played by these interplanetary dust particles in supplying water and carbonaceous molecules on the young Earth.