Interplanetary Dust Particle

Synonyms

Brownlee particle; IDP

Definition

In addition to the Sun; the planets plus their satellites; smaller bodies including asteroids, comets, and meteoroids; and Kuiper beltobjects, the roughly defined plane of the solar system contains gas and dust, referred to as the interplanetary medium. The dust grains are, naturally, called interplanetary dust particles, although that nomenclature (and particularly the abbreviation IDPs) is often used to designate particles of presumed interplanetary origin collected on the Earth, primarily in the stratosphere but also from Antarctic and Greenland ice. In the interplanetary medium, sunlight scattered by the dust is responsible for the phenomena of the zodiacal light (the “false morning” of poets, including Omar Khayyam) and the gegenschein (a very faint glow in the antisolar direction). In addition, interplanetary dust particles produce meteors (“shooting stars”) when they strike the Earth’s atmosphere and are incinerated as a result of...