Micrometeorites come from asteroids and comets, many as old as our solar system. By finding and comparing rare collections from Antarctica and the mid-Pacific, EU-funded researchers are now able to make guesses about the conditions that Earth experienced throughout its history.
Micrometeorites that have survived descent through the atmosphere provide information on the size, composition and source of cosmic dust landing on Earth. Individual particles range in size from 50 μm to 2 mm. Although they are of interest, it is the collection as a whole that provides the greatest insights.
Further details: Poor man's space probe reveals the Earth's past