[troutman]

Mars has lost an Arctic Ocean's worth of water

http://www.cbsnews.com/news/mars-had...-of-years-ago/

NASA scientists for the first time have calculated that the Red Planet held more water than the Arctic Ocean. Using powerful telescopes to measure signatures of water in the planet's atmosphere, they estimated that in its youth, the planet would have probably had an ocean more than a mile deep covering almost half of its northern hemisphere.

Based on their calculations, the scientists estimate that Mars has lost 87 percent of its ancient ocean to space and that the remaining 13 percent is likely stored in the polar ice caps.