Fig. 1.

Temporal evolution of the partial surface pressures P _surf of H, O and C normalized to the total initial surface pressure P _total for the expected outgassed volatile amounts of the Mars-like exomoon shown in Table 2. Panel a) corresponds to the lower degassed values, and panel b) to higher degassed volatile amounts. H₂O condensation of an outgassed steam atmosphere will, according to Lebrun et al. (2013) and Hamano et al. (2013), occur at ∽1–4 Myr at ~1 AU