Thermal segregation of water ice on the Galilean satellites

The susceptibility of dirty ice surfaces to a water cold-trapping process in the Galilean satellites' local bright patches, in association with preferential removal from dark areas, is inferred on the basis of a consideration of the thermal sublimation of ice. A decade time-scale segregation of the surface into bright icy regions and dark ice-free lag deposit regions would be the main consequence of such a process. While ion sputtering and micrometeorite bombardment do not appear to be of sufficient magnitude for a prevention of the process on Callisto and Ganymede, sputtering on the trailing side of Europa may be able to prevent segregation.