Nereus Crater on Mars . ... Credit Copyright: Mars Exploration Rover Mission , JPL , NASA ; Image Processing: Kenneth Kremer Explanation: It was along the way. The robotic rover Opportunity currently rolling across the Meridiani Plain on Mars has a destination of Endeavour Crater , a large crater over 20 kilometers across which may yield additional clues about the cryptic past of ancient Mars. ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ...