Lawrence Berkeley National Laboratory

We use TOUGH+/GasH2O to study the effects of a heat source buried in the Martian permafrost to evaluate the possibility of establishing a wet zone of liquid water, in which terrestrial microorganisms could survive and multiply. Analysis of the problem indicates that (1) only a limited permafrost volume (not exceeding 0.35 m in radius) is affected, (2) a "wet" zone with limited amounts of liquid water de-velops (not exceeding 8 and 0.7 kg for a 250 W and a 62.5 W source, respectively), (3) the wet zone per-sists for a long time, becomes practically stationary after t = 20 sols because of venting into the Martian atmosphere, and its thickness is limited and decreases slowly over time, (4) a "dry" zone (where SG > 0.9) evolves, continues to expand (albeit slowly) with time, but its extent remains limited, and (5) the ice front surrounding the wet zone is self-sharpening. For a range of initial conditions investigated, evolution of the liquid water mass occurs at approximately the same rate, reaches roughly the same maximum, and occurs at about the same time (10 to 20 sols; 1 sol = 24.39 hours).