Pasadena, Calif. – The Mars rover Spirit has uncovered the strongest evidence yet that the planet used to be wetter than previously thought, scientists reported Monday.
The robot analyzed a patch of soil in Gusev Crater and found that it was unusually rich in silica. The presence of water would have been necessary for the production of such a large deposit of silica, scientists said.
“This is a remarkable discovery,” principal investigator Steve Squyres of Cornell University said in a statement. “It makes you wonder what else is still out there.”
Spirit previously found clues of water from long ago in the crater through the presence of sulfur-rich soil, water-altered minerals and explosive volcanism.
But the latest find is compelling because of the high silica content, researchers said, raising the possibility that conditions may have been favorable for the emergence of primitive life.
It’s unclear how the silica deposit formed. One possibility, officials said, is that the soil mixed with acid vapors in the presence of water.
But other researchers believe that the deposit was created from water in a hot-spring surrounding.
The durable Spirit and its twin, Opportunity, have been working on overtime since completing their primary, three-month mission in 2004.
For eight months, Opportunity has explored the rim of Victoria Crater on the opposite side of the planet. Scientists are looking for a safe opening to send the rover in.
Engineers with Lockheed Martin and Ball Aerospace & Technologies Corp. in Colorado helped design and build various parts of the spacecraft.
Colorado researchers and engineers also spent months at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., during and after the rovers’ landings.
They expected the machines to explore rocks and soils for three months before they failed.
Three years later, the rovers have traveled more than 10 miles between them and snapped photos and spectroscopic images of rock, salt, craters and clouds.
Denver Post staff writer Katy Human contributed to this report.
