Low-temperature thermal reactions between SO2 and H2O2 and their relevance to the jovian icy satellites

Here we present first results on a non-radiolytic, thermally-driven reaction sequence in solid H2O + SO2 + H2O2 mixtures at 50–130 K, which produces sulfate ( SO 4 2 - ), and has an activation energy of 53 kJ/mole. We suspect that these results may explain some of the observations related to the presence and distribution of H2O2 across Europa’s surface as well as the lack of H2O2 on Ganymede and Callisto.