Ice on Mars

Scientists have declared for certain that the white substance found by Phoenix Lander on Mars was ice and not salt. After scientists discovered white substance they thought it was either ice or salt. However, as the substance 'disappeared' they were lead to believe that it was in fact ice.

“"Salt does not behave like that," said Mark Lemmon, a scientist at Texas A&M University who is in charge of Phoenix's stereo surface imager. "We found what we were looking for. This tells us we have water ice within reach of the arm."”Source: Washington Post

This is incredibly cool!