Planetary magnetospheres: 1991–1993

This paper briefly summarizes published work in the field of planetary magnetospheres from 1991 to mid-1993. The 1992 Ulysses fly-by and the proximity of Jupiter for remote sensing have meant that the Jovian magnetosphere has dominated interest in the field, resulting in studies of the interaction of magnetospheric plasma with dust grains as well as the satellite Io, the morphology and chemistry of the Io plasma torus, the aurora, plus plasma processes in the middle magnetospheric current sheet and outer magnetosphere. Two debates (about the plasma sources and transport rate and about the degree of symmetry of the magnetic field) have dominated recent work on the magnetosphere of Saturn. The effects of highly asymmetric magnetic fields on magnetospheric configurations and processes have been the major themes of work on the outermost giant planets since Voyager 2 flew past Uranus and Neptune in 1986 and 1989 respectively.