Implications of Voyager data for energetic ion erosion of the icy satellites of Saturn

Abstract

The possible production of a neutral particle “torus” by magnetosphere particle sputtering of the icy satellites (Enceladus, Tethys, Dione, Rhea) of Saturn is discussed. Particle spectra from the Voyager low‐energy charged particle experiment are used together with laboratory‐derived erosion rates and velocity distributions for the ejected species. An extended torus region in the inner magnetosphere of Saturn is expected, with H2O escape fluxes in the vicinities of the satellites varying from ∼2 to 7×107 mol/cm²/s for incident protons and from ∼6 to 14×109 mol/cm²/s if the incident ions are all oxygen.