After a journey of three years and 13 miles, the Opportunity rover has reached the rim of Endeavour crater on Mars. The crater is about 14 miles in diameter and hundreds of feet deep, so it exposes layers of rock deposited hundreds of millions of years ago. This is likely to be the last destination for the rover, which arrived on Mars in January 2004. It will explore the crater's rim for weeks or months before possibly entering the crater. Scientists suspect that the dark rocks in the foreground of this panoramic view of the crater's rim are of a type that Opportunity has not yet sampled. [NASA/JPL/Cornell/ASU]