Interplanetary Dust Cloud - Dust Particle Life Cycle

Dust Particle Life Cycle

The main physical processes "affecting" (destruction or expulsion mechanisms) interplanetary dust particles are: expulsion by radiation pressure, inward Poynting-Robertson (PR) radiation drag, solar wind pressure (with significant electromagnetic effects), sublimation, mutual collisions, and the dynamical effects of planets (Backman, D., 1997).

The lifetimes of these dust particles are very short compared to the lifetime of the Solar System. If one finds grains around a star that is older than about 100,000,000 years, then the grains must have been from recently released fragments of larger objects, i.e. they cannot be leftover grains from the protoplanetary disk (Backman, private communication). Therefore, the grains would be "later-generation" dust. The zodiacal dust in the solar system is 99.9% later-generation dust and 0.1% intruding interstellar medium dust. All primordial grains from the Solar System's formation were removed long ago.

Particles which are affected primarily by radiation pressure are known as beta meteoroids. They are generally less than 1.4 x 10−12 g and spiral outward from the sun into interstellar space.