A predicted Triton plasma torus in Neptune's magnetosphere

Abstract

We investigate the possibility of the formation of a plasma torus generated by the satellite Triton in the magnetosphere of Neptune. We solve a set of coupled differential equations that describe the evolution of material sputtered from the surface or atmosphere of Triton in the conditions likely to exist in an assumed Neptunian magnetosphere for various combinations of nitrogen and methane that may exist on Triton. The model assumes a mechanism for transport that gives upper limits for predicted torus concentrations. Our conclusion is that a successful detection of plasma by the Voyager Plasma Science instrument may be possible and could be an important source of information about the composition of Triton's surface and atmosphere.