This proposal is concerned with the interaction of the solar wind, or other flowing plasma, with non-magnetic solar system bodies such as Venus, Mars, Titan and comets. Research in this area contributes to a broader understanding of solar-planetary relations in general and of comparative magnetospheres and ionospheres. The research emphasizes two particular aspects of solar wind interactions with non-magnetic planets: (1) collisional interactions between plasmas and neutrals, and (2) evolution of plasma distribution functions in induced magnetospheres. Specifically, proposed research tasks are: (1) completing a two- dimensional, magnetohydrodynamic model of the inner coma of comet Halley, (2) developing a two-dimensional, MHD model of the ionospheres of Mars and Titan, (3) investigating cometary pickup ions using test particle methods and quasi-linear theory, and (4) studying superthermal neutral and ion populations in the inner coma of comet Halley.
