Opportunity completed its three-month prime mission on Mars in April 2004. During its bonus extended operations since then, it spent two years exploring in and around Victoria Crater. Victoria is about 800 meters (half a mile) in diameter. At about 22 kilometers (14 miles) in diameter, Endeavour is about 28 times wider. After the rover science team selected Endeavour as a long-term destination, observations of Endeavour's rim by NASA's Mars Reconnaissance Orbiter revealed the presence of clay minerals. This finding makes the site an even more compelling science destination. Clay minerals, which form exclusively under wet conditions, have been found extensively on Mars from orbit, but have not been examined on the surface.
JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate, Washington. For more about the twin rovers Spirit and Opportunity, see http://marsrovers.jpl.nasa.gov.
Guy Webster (818) 354-6278
Jet Propulsion Laboratory, Pasadena, Calif.