"Signs of liquid water add to 'Life on Mars' debate"

Perhaps the best evidence so far for liquid water on Mars. Today, not long ago.

An orbiter going around Mars has photographed gullies which indicated that water had flowed there in the past decade.

"These observations give the strongest evidence to date that water still flows occasionally on the surface of Mars," said Michael Mayer, head of NASA's Washington-based Mars Exploration Program.