While NASA's Mars rover Opportunity toils away inside a crater, its robotic twin Spirit has rolled over its first rock outcrop on the other side of the planet.
NASA scientists were elated at Spirit's rocky find, which came as the rover rolled backwards along the foot of a region called the West Spur at the Columbia Hills.
"This is what we came to the Columbia Hills for," said an excited Matt Golombek, a rover science team member, during a press briefing today at NASA's Jet Propulsion Laboratory (JPL). "We've been seeking it, and we've finally found it."
An initial look at the outcrops under Spirit's wheels appears to show rocks with layers of materials stacked on top of each other. But researchers aren't sure if the layers depict the slow depositing of sediment or volcanic rock over time, or if the effect is the result of wind erosion. They may be some of the oldest rocks seen during Spirit's mission, dating back three or four billion years.