Sublimation pressures of common volatiles at low temperature and maps of supervolatile cold traps on the Moon

Abstract

Astrophysical processes can involve sublimation rates too low to be measured in the laboratory. Here, measured vapor pressures of solid H2O, Ar, CO2, H2S, NH3, SO2, CH4, HCN, CH3OH, and C2H4 are reviewed, fitted, and robustly extrapolated to lower temperatures. Knowledge gaps regarding vapor pressures are identified for several chemical species. Maps of lunar cold traps for supervolatiles are presented based on sublimation rates time-averaged over diurnal and seasonal cycles of measured surface temperatures for the north and south polar region. The cold trap areas for these supervolatiles are all much smaller than for H2O.

Topics & Concepts