interplanetary dust

As interplanetary dust is called matter from our solar system with masses below 10-5 g and radii below 100 microns. Probably the most important source of interplanetary dust are comets, asteroids and other small bodies and fragments resulting from collisions between larger particles. In addition to evaporate near the sun particles of larger pieces of matter. The dust particles do not reside in the solar system. Very small dust particles are driven by the radiation pressure of sunlight outward larger particles approach by the Poynting - Robertson effect, more and more of the sun, where they are vaporized or fragmented.

With the aid of dust detectors satellites interplanetary dust can be analyzed. Some of these particles contain, inter alia, polycyclic aromatic hydrocarbons. Partly also dust particles from aircraft can be picked up in about 20 km altitude, as hitherto on earth unproved mineral Brownleeit. Further analysis options are the investigation of microscopic craters on the moon and the observations with satellites in the infrared range.

On the earth take a day depending on estimate 100 to 10,000 tons of matter in the form of micrometeorites. Since the air resistance at small particles outweighs the gravity, this does not burn up in the atmosphere, but float to the ground, there are, however, difficult to distinguish from terrestrial debris.

An interplanetary dust accumulation within 2.5 AU distance from the sun is responsible for the phenomenon of the zodiacal light, which is sunlight reflected from dust.