Many tons of dust grains, including samples of asteroids and comets, fall from space onto the Earth's atmosphere each day. An even larger amount of spacecraft debris particulates reenter the Earth's atmosphere every day. Once in the stratosphere this "cosmic dust" and spacecraft debris joins terrestrial particles such as volcanic ash, windborne desert dust and pollen grains. High flying aircraft with special sticky collectors capture this dust as it falls through the stratosphere, before it becomes mixed with Earth dust. The ultra-clean Cosmic Dust Laboratory, established in 1981 to handle particles one-tenth the diameter of a human hair, curates over 2000 cosmic dust particles and distributes samples to over 30 investigators.

Cosmic dust grains include our only samples from comets, probably containing material in the same condition as when the solar system began to form. Examination of cosmic dust reveals much about the populations of interplanetary dust and orbital debris particles. Such information is useful to engineers planning proctection of Space Station against damage from high-velocity dust grains. The terrestrial dust and spacecraft debris particles are of considerable interest to atmospheric scientists and climatologists, since they influence some global atmospheric reactions.

Cosmic Dust Laboratory