Italian scientists working on the European Space Agency’s Mars Express mission announced on Wednesday that a 12-mile-wide underground liquid pool — not just the momentary damp spots seen in the past — had been detected by radar measurements near the Martian south pole.
[…]
… scientists could not measure the thickness of the lake, but […] it had to be at least a yard or so thick for the radar pulses to bounce back.
…a back-of-the-envelope calculation indicated several hundred million cubic meters of water. That’s tens of billions of gallons.
I, for one, bid these scientists beware:
Beware the Martian winter–and seek not to pass through the Gates of Death that guard the citadel of ice!