xp65 writes: "The Mars Express High Resolution Stereo Camera imaged a region close to Ma'adim Vallis, one of the largest canyons on Mars. The images cover 138 x 70 km, roughly the size of Cyprus. A sharp boundary is visible in the centre, dividing dark material to the west and light material to the east. Scientists suspect that this feature is most likely the edge of a basaltic lava flow. The pictures are centred at about 29S and 182E and have a ground resolution of 15 m/pixel."