MODELING THE GALILEO DUST MEASUREMENTS AT JUPITER

We discuss our modeling that is aimed to reproduce the observed dust i mpact rates during the first two Ganymede encounters of Galileo. We us e a detailed fields and particles model of the magnetosphere and simul taneously follow the dynamics and the charging history of small dust p articles. We assume Io to be the only source of the escaping dust grai ns and show that our model matches the gross characteristics of the ob servations. We argue that the large scale dawn-to-dusk electric field can be responsible for shaping the emission pattern of dust from the I o plasma torus. The emission pattern shows a minimum flux toward the S un, perhaps explaining why the observed fluxes did not increase as Gal ileo approached the source region of the dust particles. We show that the general shape of the trajectories of the grains offers a good expl anation for the sudden shift in the observed direction of the dust imp acts. Modeling the observed dust impact rates gives an excellent oppor tunity to test our particles and fields model of Jupiter's magnetosphe re.