Kasei Valles and Sacra Fossae, in perspective view.
Mars Express flew over the boundary between Kasei Valles and Sacra Fossae while the High Resolution Stereo Camera (HRSC) operated by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) imaged the region, acquiring spectacular views of chaotic terrain. The images are centred at 12°N, 285°E and have a ground resolution of about 21 metres per pixel. They cover 225 kilometres by 95 kilometres or 21,375 square kilometres, an area roughly half the size of the Netherlands.
The image shows an old 35-kilometre diameter impact crater in the north. The crater’s southwestern rim is heavily eroded. The erosion was caused primarily by flowing water. The source of the water was located in Echus Chasma, which lies roughly 850 kilometres to the southwest.
The crater floor and the northwestern part of the imaged region are remarkably flat and have been formed by sediments and basaltic lava flows originating from the Tharsis volcanic region.