Chemical Schemes for Surface Modification of Icy Satellites: a Road Map

M.L. Delitsky, A.L. Lane (JPL)

The icy Galilean satellites of Jupiter are subject to magnetospheric plasma ion bombardment which induces chemical changes within the ice. The possible detection of CO2 on the surfaces of these satellites by the Galileo spacecraft (Carlson R.W.,et al.,Science, 274,385(1996)) makes for a more complicated chemistry and increases the number of chemical compounds that may be present. We outline chemical schemes for the irradiation of pure and mixed ices H2O/CO2 with Jovian plasmas, which suggest that the following species should also occur on Europa, Ganymede and Callisto: C3O2, H2CO3, H2O2, CO3, HO2, CO, H2CO, CH2CO, KOH, and K2O. Column abundances of compounds in the ice are calculated using a specified energy input, and 'G values' (yield/100 eV). As an example, for Europa, column density of H2O2 = 0.2064 g/cm2. Column density of H2CO = 0.4524 g/cm2 , and for H2CO3 =0.4703 g/cm2.