Mars surface. Landing site of the Mars Exploration Rover Opportunity on the surface of Mars. Opportunity landed on 24 January 2004 in the Meridiani Planum region, east of Valles Marineris near the Martian equator. The lander carrying the rover came to a standstill in a small crater (centre). The white dot at centre is the lander, and the black spot above and to the right of the lander is believed to be the rover. Opportunity, and an identical rover called Spirit, will study Martian rocks and look for water on the planet. This 125-metre-wide image was taken by the camera on NASA's Mars Global Surveyor orbitor.