Liquid Water On Mars?

Team members who ran the Phoenix Mars Lander mission last year are about to publish a paper which argues the mission found liquid water at the landing site. The paper contends that globules photographed on the lander's legs were in fact brine-- a mixture of soil and liquid saltwater-- that splashed onto the legs during landing. The presence of liquid water on the surface of Mars, of course, would radically change the prospects for life on Mars.

Not every team member agrees with the conclusion of the paper. Some insist the surface-- especially in the polar regions where Phoenix landed-- is too cold and too dry to support liquid water. Indeed, the "warmest" temperature at the Phoenix site is about -20 degrees F. Backers of the paper, including team leader Peter Smith, point out the salty water doesn't freeze at the same point freshwater does.

The presumed failure of Viking to find life on Mars in the 1970s was disputed by the lead investigator of the biology suite. Now, we may have a controversy over surface liquid water. Human explorers on Mars could settle such questions quickly.