The investigators will examine solar wind interactions with non-magnetic solar system bodies such as Venus, Mars, Titan, and various comets. Research in this area contributes to a broad, comparative understanding of planetary ionospheres and induced magnetospheres that form on inherently non-magnetic bodies. The main effort is theoretical modeling of this interaction using several complementary techniques. Primary emphasis of the research will be collisional interactions between plasmas and neutral gases and the evolution of plasma distribution functions in induced magnetospheres.