On the Habitability of Saturn’s Icy Moon Enceladus

by Ruth-Sophie Taubner (University of Vienna)

DeGeer, Geovetenskap

DeGeer, Geovetenskap

Saturn’s icy moon Enceladus became famous for its erupting water plumes, which most likely origin in a (global) subsurface liquid water ocean. The detection of silicon-rich, nanometre-sized dust particles and the abundance of various salt components in a certain population of E-ring grains suggest that its subsurface aquifer is (or at least was) in direct contact with the underlying rocky core, which might imply water-rock interactions like serpentinization. Therefore, the most promising area on Enceladus where life may exist is at the seafloor of this subsurface water reservoir. We performed numerical experiments to test the possibility of low temperature serpentinization on Enceladus. Further, we focused on the possibility that Enceladus’ subsurface ocean might be a habitat for methane producing Archaea, i.e. methanogens. Therefore, we tested different hydrogenotrophic methanogenic strains in respect to their tolerance towards potential inhibitors detected in Enceladus’ plume. Based on the results of these experiments, we performed high pressure experiments in the range of 10 to 90 bar. Our study combines studies of various scientific fields and introduces novel aspects on potential habitats for microbial life in the Solar System, especially concerning icy moons.