Rover Gives NASA an "Opportunity" to View Interior of Mars

NASA's Mars exploration rover Opportunity is allowing scientists to get a glimpse deep inside Mars. Perched on a rippled Martian plain, a dark rock not much bigger than a basketball was the target of interest for Opportunity during the past two months. Dubbed "Marquette Island," the rock is providing a better understanding of the mineral and chemical makeup of the Martian interior. "Marquette