Dynamical Models of Kuiper Belt Dust in the Inner and Outer Solar System

We report several results related to the dynamical evolution of dust producedin the Kuiper Belt (KB). We show that its particle size frequency distributionin space is greatly changed from the distribution at production, as a resultsof the combined effects of radiation forces and the perturbations of theplanets. We estimate the contribution of KB dust to the zodiacal cloud bycalculating the radial profile of its number density near the ecliptic. We alsostudy the contribution of KB dust to the population of interplanetary dustparticles (IDPs) collected at Earth, by calculating geocentric encountervelocities and capture rates. Our models show, in contrast with previousstudies, that KB dust grains on Earth-crossing orbits have high eccentricitiesand inclinations and, therefore, their encounter velocities are similar tothose of cometary grains and not to asteroidal grains. We estimate that at most25% in number of captured IDPs have cometary or KB origin; the KB contributionmay be as low as 1%-2%. We present the velocity field of KB dust throughout thesolar system; this, together with the number density radial profile, ispotentially useful for planning spacecraft missions to the outer solar system.Comment: 25 pages (pre-print format), including 5 figures. Published in AJ (2003