While NASA's Mars rover Opportunity has enjoyed the headline-grabbing discoveries, Spirit has been biding its time in Gusev Crater, waiting for its moment in the Sun. That moment may soon be at hand. The vehicle has climbed 9 meters (30 feet) high into the Columbia Hills, where its Panoramic camera acquired this near-true-color mosaic of the surrounding plain (Gusev's rim appears on the horizon). Spirit's spectrometers are currently examining a rock outcrop named Clovis whose chemical composition suggests past interactions with liquid water. Meanwhile, on the other side of Mars, Opportunity continues to investigate Endurance Crater, where it is finding intriguing but as-yet unexplained chemical differences between rocks near the rim and rocks near the floor. Both rovers remain in excellent health despite the onset of winter, but are showing signs of age. "They're developing aches and pains, just as you would if you were operating two times past your design life," says rover mission manager Chris Salvo (NASA/Jet Propulsion Laboratory).