NASA has decided the potential science value gained by sending Opportunity into a martian impact crater likely outweighs the risk of the intrepid explorer not being able to get back out. Opportunity has been examining the rim of the stadium-sized “Endurance Crater” since late May. The rover team used observations of the depression to evaluate potential science benefits of entering the crater and the traversability of its inner slopes.

More than a month into bonus time after a successful primary mission on Mars, NASA’s Spirit rover has sighted possibly layered rock in hills just ahead, while twin Opportunity has extended its arm to pockmarked stones on a crater rim to gather clues of a watery past.

Rates of change in surface temperatures during a martian day indicate differences in particle size in and near “Bonneville Crater.” Temperature information from the miniature thermal emission spectrometer on NASA’s Mars Exploration Rover Spirit is overlaid onto a view of the site from Spirit’s panoramic camera.

NASA’s Mars Exploration Rover Opportunity has begun sampling rocks blasted out from a stadium-sized impact crater the rover is circling, and the very first one may extend our understanding about the region’s wet past. Opportunity is spending a few weeks examining the crater, informally named “Endurance,” from the rim, providing information NASA will use for a decision about whether to send the rover down inside. That decision will take into account both the scientific allure of rock layers in the crater and the operational safety of the rover. Opportunity has completed observations from the first of three planned viewpoints located about one-third of the way around the rim from each other.

This cylindrical-projection mosaic was created from navigation camera images that NASA’s Mars Exploration Rover Spirit acquired on sol 121 (May 6, 2004). Continuing its trek toward the “Columbia Hills,” Spirit drove 96.8 meters (318 feet) – half of which was performed in auto-navigation mode – and broke its record for the longest distance traveled in one sol. That drive brought the mission total to 1,669 meters (1.04 miles), flipping the rover’s odometer over the one-mile mark.

Scientists and engineers celebrated when they saw the first pictures NASA’s Opportunity sent from the rim of a stadium- sized crater that the rover reached after a six-week trek across martian flatlands. Multiple layers of exposed bedrock line much of the inner slope of the impact crater informally called “Endurance.” Such layers and their thicknesses may reveal what the environment on Mars was like before the salty standing body of water evaporated to produce the telltale rocks that were explored in the tiny “Eagle” Crater. That