Water induced sediment levitation enhances downslope transport on Mars

On Mars, locally warm surface temperatures (~293 K) occur, leading to the possibility of (transient) liquid water on the surface. However, water exposed to the martian atmosphere will boil, and the sediment transport capacity of such unstable water is not well understood. Here, we present laboratory studies of a newly recognized transport mechanism: “levitation” of saturated sediment bodies on a cushion of vapor released by boiling. Sediment transport where this mechanism is active is about nine times greater than without this effect, reducing the amount of water required to transport comparable sediment volumes by nearly an order of magnitude. Our calculations show that the effect of levitation could persist up to ~48 times longer under reduced martian gravity. Sediment levitation must therefore be considered when evaluating the formation of recent and present-day martian mass wasting features, as much less water may be required to form such features than previously thought

Survival of Methanogenic Archaea from Siberian Permafrost under Simulated Martian Thermal Conditions

Since ESA mission Mars Express determined water on Mars, a fundamental requirement for life, as well as the presence of CH4 in the Martian atmosphere, which could only have originated from active volcanism or from biological sources, it is obviously that microbial life could still exist on Mars, for example in the form of subsurface lithoautotrophic ecosystems, which are also exist in permafrost regions on Earth. Present work deals with the resistance investigation of methanogenic archaea from Siberian permafrost complementary to the already well-studied methanogens from non-permafrost habitats under simulated Martian conditions. The methanogenic archaea in pure cultures as well as in permafrost samples represent higher survival potential (up to 90 percent) than the referent organisms (0.3-5.8 percent) after 22 days of exposure to thermo-physical Martian conditions at low- and mid-latitudes. It is suggested that methanogens from terrestrial permafrost seem to be more resistant against Martian conditions and could be used as a prime candidates for the search for extraterrestrial life