III.A Sources and Sinks for Planetary Dust
The sources of IDP include at least: asteroid collisions, comet activity and collisions in the inner solar system, comet collisions in the Kuiper Belt (KB), and ISM grains. The main physical processes affecting IDP are: expulsion by radiation pressure, inward Poynting-Robertson radiation drag, solar wind pressure (including significant electromagnetic effects), sublimation, mutual collisions, and gravitational influence of planets.
No rigorous accounting has been made of the relative strengths of the grain sources, nor of the effects of the various destruction and dynamical processes on the equilibrium spatial distribution of the dust. Difficulties arise not simply because of complex cloud structure but also from problems in comparing multi-wavelength data sets which do not measure precisely the same lines-of-sight simultaneously and are often subject to large calibration error. Very different models of the spatial distribution of the material have produced acceptable fits to visual and IR data (e.g. Giese and Kniessel 1989). Much work remains to be done combining observational data with a priori models of the spatial distribution based on dynamical evolution of the grains.
Last updated March-06-1998