The Phoenix lander confirmed the existence of large amounts of water near the surface of mars today, when a soil sample heated in the lander’s oven melted, yielding water in liquid state.
For hard SF geeks, I heartily recommend Kim Stanley Robinson’s “Red Mars” series, which chart the existance of the first human colonists of Mars through to the terraforming of the planet. In the forward (I think) he mentions that his book was a true to the science as he could make it, except that he’d had to posit the existance of a lot more water on mars than was safe to assume, given the state of the science.
Well, it looks like he guessed right. If the human race ever gets off this rock and onto another, that water is going to have a role to play.
