The Magnetospheres of the Outer Planets

Abstract

The past four years have witnessed the culmination of the initial reconnaissance of the giant outer planets and their magnetospheres. This includes more mature modeling of dynamics of and processes in the magnetospheres of Jupiter and Saturn, the first detailed reports on the fields and particles environment of Uranus, and the initial reports concerning the magnetosphere of Neptune, first sampled directly by Voyager 2 in August, 1989. Of the major bodies of the outer solar system, only the asteroids and the Pluto/Charon system remain unvisited, although some attention was focused on the latter during this quadrennium. We review work on and our understanding of the magnetospheres of all of the outer planets during the previous four years.

Giant Planet Magnetospheres

“…Adiabatic heating of such ions as they are transported inwards can provide the energies of the hot plasma in the plasma sheet. To provide the observed high fluxes of particles at Me V energies, however, a variety of acceleration processes have been proposed, reviewed in Dessler (1983) and by McNutt (1991).…”

“…[These studies are too numerous to cite and are summarized by McNutt (1991).] At the same time, argue that the observations do not rule out all MHD interchange models but may just put a limit on the diffusion rate.…”

“…With the Voyager spacecraft having made measurements with the same complement of instruments at the fo ur planets we can now make a comparison of the family of magnetospheres. The topic of planetary magnetospheres has been reviewed previously by Siscoe & Slavin (1979), Stern & Ness (1982), Bagenal (I985a), Connerney (1987), McNutt (1991).…”