Martian surface. True colour image from the panoramic camera on NASA's Mars exploration rover Opportunity of the Erebus Crater. A portion of the crater's rim is seen at top centre. Opportunity and its sister rover Spirit were launched in the summer of 2003. Opportunity landed on Mars on 24th January 2004. Its mission is to analyse soil and rocks and search for water. Image obtained on 28th November 2005, Opportunity's 657th Martian day.