On a Possible Mechanism for the Formation of Oxygen Atmospheres on Jupiter's Icy Satellites.
Boyarchuk, K. A.; Karelin, A. V.; Shematovich, V. I.
Astronomicheskii Vestnik, vol. 34, p. 12 (2000)
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On the basis of the kinetic theory of water vapor plasma exposed to a hard ionizer, an attempt is made to describe a possible physicochemical mechanism for the formation of oxygen atmospheres on Jupiter's icy satellites. It is shown that oxygen atmospheres on the satellites may appear as a result of ionization of water molecules by energetic ions from the Jovian magnetosphere. The presence of water molecules in the atmospheres may be a result of sublimation or sputtering of the planet's icy surfaces by hard radiation, i.e., by the solar ultraviolet radiation and the energetic ions of the solar wind and Jupiter's magnetosphere. At a satellite surface temperature of T <= 125 K, the steady-state concentrations of atomic and molecular oxygen ([O] = 2.2 x 108 cm-3 and [O2] = 1.8 x 108 cm-3, respectively) are attained within 200 years. All other neutral and charged medium components can be treated as minor admixtures.