Micrometeorites: Extraterrestrial particulate matter on the earth

Abstract

About 40,000 tons of cosmic dust rains on the earth every year – this constitutes the sub millimeter extraterrestrial material which is released into the inner solar system either by collisions between asteroidal material or by release from comets during their perihelional passage around the sun. This particulate extraterrestrial material constitutes 95% of all extraterrestrial matter that is attracted by the earth. This forms an important resource of solar system material and more importantly, it is available almost everywhere on earth. Either way, this material offers a unique window to understand not only early solar system processes, but also the earth crossing meteoroid complex. Cosmic dust has been collected from various domains, each of which offers advantages which are unique.