Re: Of millibars
Note that my figure of 20m was plucked out of the air, and I assumed a total cover, rather than the ~50% cover that looks more likely from the pitted terrain.
So you should divide my figures by about 5 to give <1 mbar. I didn't do a proper calculation, so I'm prepared to accept 0.36 mbar as the result of a "correct" calculation...