Martian surface. Coloured image from the panoramic camera on NASA's Mars exploration rover Opportunity of exposed rock in Victoria Crater (left). The smaller crater at right is informally known as Sputnik and is about 20 metres away from the rover. 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 taken on Opportunity's 952nd Martian day, 28th September 2006.