Antarctic pond may yield Mars water clues

Earth's most unlikely body of water, in frigid Antarctica, is liquid only because its salt content -- the highest on Earth -- keeps it that way, scientists say. Don Juan Pond, located in the freezing McMurdo Dry Valleys, one of the coldest and driest places on Earth -- and with similarities to the frozen deserts of Mars -- could have implications for understanding water flow on Mars both in the past and maybe in the present, they said. A research team led by Brown University geologists has discovered how the pond gets the salty water it needs to exist. The scientist have determined water sucked out of the atmosphere by parched, salty soil is the source of the saltwater brine that keeps the pond eight times more salty than the Dead Sea and keeps it from freezing, a university release said Thursday. Antarctica is an excellent model for the cold, dry desert of Mars, and the findings about Don Juan Pond and how it stays liquid at temperatures far below freezing could offer clues about the possibilities for flowing water on Mars, the researchers said. "Broadly speaking, all the ingredients are there for a Don Juan Pond-type hydrology on Mars," Brown geologist James Dickson said. "It's not likely that there's enough water currently on Mars for the water to form ponds, but stronger flows in Mars's past might have formed plenty of Don Juan Ponds."