Opportunity Mars Exploration Rover at the Erebus Crater on Mars. This is a composite of images taken by the Mars Exploration Rover Opportunity between 23rd November and 5th December 2005. It is a polar view covering 360 degrees, so that the Martian horizon appears around the edge of the frame. At this time, Opportunity was on the rim of the wide but shallow Erebus Crater in the Meridiani Planum region of Mars. Opportunity landed on Mars on 25th January 2004 and has conducted many studies of soil, rocks and the atmosphere. The colours here are approximately true.