Magnetospheric charge-exchange effect on the electroglow of Uranus

Abstract

One common feature of the magnetospheric systems of the outer planets explored by the Pioneer 10 and 11 and the Voyager 1 and 2 spacecraft is that extended distributions of neutral gas of planetary exospheric origin and/or of satellites–rings origin coexist with the magnetospheric plasma. This property invariably leads to the occurrence of charge-exchange loss of the charged particles in the inner magnetospheres of Jupiter, Saturn and Uranus. With emphasis on the Uranian system I examine here the idea that the injection of the recombined fast neutrals into the planetary upper atmosphere might be contributing in part to the generation of the dayside electroglow. The recent results from the Voyager 2 encounter also permit the idea that the associated impact ionization effect could be important in maintaining the nightside ionosphere.