Sputtering of ices in the outer solar system

摘要: Exploration of the outer solar system has led to studies in a new area physics: electronically induced sputtering low-temperature, condensed-gas solids (ices). Many icy bodies were found be bombarded by relatively intense fluxes ions and electrons, causing both changes their optical reflectance ejection (sputtering) molecules from surfaces. The small cohesive energies afford large rates electronic excitations produced solid fast electrons. Such produces an ambient gas about body, often source local plasma. This colloquium outlines physics ices its relevance several outer-solar-system phenomena: sputter-produced plasma trapped Saturn{close_quote}s magnetosphere; O{sub 2} atmosphere on Europa; absorption features such as SO{sub surface Europa and, possibly, 3} Ganymede. {copyright} {ital 1996 American Physical Society.}