NASA's Mars Rover Finds Mineral Traces Left by Water

NASA revealed that the Opportunity rover, which has been prowling the plains and craters of the Red Planet since 2004, had discovered, well, Martian patio tiles or rectangular formations that looked awfully similar.

Rectangles in the Martian soil are nothing to do with life, the rectangles are one more clue that biology might indeed be or at least have been possible on Mars.

Opportunity and its rover twin Spirit have spent much of their years of exploration looking for clues to water on Mars, which, of course, is a sine qua non for life as we know it.

The evidence has piled up, both in terms of topographic scars that could only have been left by flowing, pooling or upwelling water; and the presence of sulfates, hydroxides and other materials that form in the presence of water. Last August, the Mars Reconnaissance Orbiter (MRO) beamed back images suggesting that liquid water may flow seasonally on Mars even today.

"Since the MRO arrived at Mars, our overarching theme has been 'follow the water,'" said mission scientist Mike Meyer at the time of the announcement. "Now we may be catching Mars in the act."