Mawrth Vallis is one of four candidate landing sites under consideration for the ExoMars 2018 mission. It is one of the oldest outflow channels on Mars, at least 3.8 billion years old. It hosts large exposures of finely layered clay-rich rocks, indicating that water once played a role here.
The image combines HRSC images from ESA Mars Express with MOLA topography data from NASA's Mars Global Surveyor. The landing ellipses under evaluation for this site selection are indicated, and cover an area of 170 × 19 km. The orientation of the landing ellipse depends on when the launch takes place within a given launch window – the sites have to be compliant with launch opportunities in both 2018 and 2020, as indicated.