PASEDENA, Calif., Jan. 7 (UPI) -- Photos from NASA's Mars rover Spirit show the Red Planet's surface is strangely cohesive and clay-like, Californa mission specialists say.
Spirit exposed the material when it dragged its collapsed air bags across the Martian surface to retract them after its Saturday night bounce-down, the Washington Post reported Wednesday.
"The way the surface has responded is bizarre," said lead rover scientist Steve Squyres of Cornell University, at the Jet Propulsion Laboratory, which is managing the mission for the National Aeronautics and Space Administration.
"It looks like mud, but it can't be mud."
The material was mashed and clumped, like something moist and viscous, and was broken away in pieces at some spots. Squyres theorized that moisture had percolated from below the surface, leaving a residue of salt that acted as cement.
A key goal of Spirit's mission is to find out whether the dry, frigid and almost airless planet might once have had surface water and possibly supported life.
Spirit is expected to dig into the crust by locking five of its wheels and spinning the sixth.