The clays on Mars that were thought to be indicative of a wet past could, instead, be formed by volcanoes.

Live Science said: “New Mars Theory Questions Red Planet’s Watery Past.”

Astrobiology Magazine said, “Clay Not Evidence of Lakes on Mars.”

New Scientist said, “Not so moist Mars: Clays may come from lava, not lakes.”  The article quotes Brian Hynek saying, “Such a result would imply that early Mars may not have been as habitable as previously thought at the time when Earth’s life was taking hold.”  Live Science, though, said Hynek is holding out hope that some of the Martian clays could have had a watery origin.

Live Science includes a 6-minute video update by John Grotzinger, project scientist for the Curiosity rover.  He’s still hoping to find evidence of a watery past in Gale Crater.  If history is a guide, scientists expected to find water-lain deposits in Gusev Crater where the earlier Spirit rover landed.  Spirit, however, only found dry volcanic deposits (8/06/2004)…..

Continue Reading on crev.info