New Theory: Mars Was Too Hot For Life

Those signs of flowing water in the past? Might've actually been lava

A new investigation of clay-like material found on the Martian surface suggests the planet did not have free-flowing water on its surface.

For years, evidence that Mars once held flowing liquid water—a key ingredient for life—has been pouring in.

NASA's surveys have shown ice-locked water at the poles, visual evidence of valleys apparently carved by water millions of years ago, and clays which appear to have formed in free-flowing water.

But the new theory by authors at Caltech University and printed in Nature Geoscience, suggests the clay may have been formed by lava which—at a temperature of 1,500C—would have been much less hospitable to life.