Spirit Mars Exploration Rover on Mars. This is a composite of images taken by Spirit between 24th and 27th August 2005. Spirit landed on Mars on 4th January 2004 and has conducted many studies of soil, rocks and the atmosphere. This image is a polar projection, with the rover at centre and the horizon around the edge. This image was taken on the 583rd-586th Martian days (sols) after landing. Spirit and its twin rover Opportunity were only designed to have a working life of around 90 sols. Martian dust accumulating on the solar panels that power the rover reduced its power levels, but on 12th March 2005 a dust devil blew much of the dust from the panels, returning them to nearly their initial levels. The colours here are approximately true.