MODELING THE SPORADIC METEOROID BACKGROUND CLOUD

The orbital distributions of dust particles in interplanetary space are revised in the ESA meteoroid model to incorporate more observational data and to comply with the constraints due to the long-term particle dynamics under the planetary gravity and Poynting-Robertson effect. Infrared observations of the zodiacal cloud by the COBE Earth-bound observatory, flux measurements by the dust detectors on board Galileo and Ulysses spacecraft, and the crater size distributions on lunar rock samples retrieved by the Apollo missions are fused into a single model. Within the model, the orbital distributions are expanded into a sum of contributions due to a number of known sources, including the asteroid belt with the emphasis on the prominent families Themis, Koronis, Eos and Veritas, as well as comets on Jupiter-encountering orbits. An attempt to incorporate the meteor orbit database acquired by the Advanced Meteor Orbit Radar at Christchurch is also discussed.