Ankle-deep water covering all of Mars. That’s how much is thought to be lurking subsurface on the red planet. Data gathered by NASA’s Mars Odyssey spacecraft has given the first global look at the total amount of water stored near the Martian surface. However, expert taking part in the annual meeting of the American Association for the Advancement of Science (AAAS) continue to be baffled by what they see following years of spacecraft observations of the planet. Increasingly, Mars appears to be a water-rich world capable of supporting future human explorers and, perhaps, home for present-day life.