Scientists Hail Ice Find on Mars

White material on Mars that was puzzling NASA scientists has turned out to be ice, Wired reports. "Are you ready to celebrate? We have ICE! Best day ever!" gushed a team scientist. The discovery of evidence of water—essential for terrestrial life—is exactly what scientists were hoping to find on Mars.

Experts were initially unsure whether the material uncovered by the lander was salt or ice. But the material has begun to disappear, an indication that it's turning into gas—a sure sign of ice. The next trick will be for the Phoenix Lander to collect the material. (More Mars stories.)