Well, not any sustainable life forms as we know, but evidence of a once habitable environment. According to an article in the New York Times, the rover Spirit found the discovery because of a broken wheel.
The right front wheel of Spirit stopped turning in March 2006. Since then, the rover has been driving backwards, dragging the lame wheel along. This May, scientists noticed a bright spot in the trail of overturned dirt.
They turned Spirit around for a closer look, finding high levels of silica, the main ingredient of window glass. They then aimed the rover at a nearby rock, wanting to break it apart to determine if the silica was just a surface coating, or if the rock was silica all the way through.
The target rock survived Spirit’s charge, but a neighboring rock cracked open. The interior of that rock, which the scientists informally named “Innocent Bystander,” turned out to be rich in silica.
On Earth, such high concentrations of silica can form in only two places: a hot spring, where the silica is dissolved away and deposited elsewhere, or a fumarole, an environment, often near a volcano, where acidic steam rises through cracks. The acids dissolve other minerals, leaving mostly silica. On Earth, both environments teem with life.
I am surprised that these two robots are still going. Not even Martian dust storms or broken wheels can keep these little critters from scouring the Red Planet from end to end.
[Photo Credit: NASA/JPL/University of Arizona]
