Why was Mt. Sharp chosen for the Curiosity Rover landing site, and what about those rounded stones that it photographed, indicative of long ago ankle to hip-deep water?  If the Martian surface is likely so full of perchlorates and life-hostile, irradiated soil, what are the chances of pockets of microbial life below ground?

The discussion later moves to Venus, Jovian moon Io, and the Chinese lander on the dark side of the moon in the final minutes:

Event Horizon discussion with Emily Lakdawalla.

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As posted:

Imagine sub-freezing temperatures and free radicals bombarding the near atmosphere-less Martian surface (oxidized and rusted red, barren), but below the Martian surface lurk big blocks of briny ice; ice with freezing cold, incredibly salty water around them and maybe just enough O2 to support some microbes.

Worth thinking about.

What are you doing with your imagination?

‘Due to the scarcity of O2 in the modern Martian atmosphere, Mars has been assumed to be incapable of producing environments with sufficiently large concentrations of O2 to support aerobic respiration. Here, we present a thermodynamic framework for the solubility of O2 in brines under Martian near-surface conditions. We find that modern Mars can support liquid environments with dissolved O2 values ranging from ~2.5 × 10−6 mol m−3 to 2 mol m−3 across the planet, with particularly high concentrations in polar regions because of lower temperatures at higher latitudes promoting O2 entry into brines’