Mars Images Indicate Wet, Explosive Past

The Mars rover Spirit has discovered several layers of rocks in a hilly region of the Red Planet that suggest a wet and violent history in the planet’s early life, scientists said Tuesday.

The six-wheeled robot has been examining rocks from three outcrops in the Gusev Crater region that show possible successive deposits of water-altered debris from explosive events. Scientists said the debris was most likely ash that settled after volcanic eruptions, but they could not rule out the possibility of an impact explosion.

“Big, explosive events were happening, and there was a lot of water around,” said principal investigator Steve Squyres of Cornell University.