Over the Rim

Gentle sand dunes and a multitude of small rocks cover the bottom of Santa Maria, an impact crater on Mars, in this December 19 view from the Opportunity rover. The rover will spend several weeks investigating the crater and the rocks around it that were blasted out by the impact. After that, Opportunity will continue its trek to a much larger crater, which is visible as a line of gentle hills at the top of the image. [NASA/JPL]