Isidis Rim

This lunar-like scene occurs along the southeastern rim of the Isidis Planitia basin. The Isidis basin is an ancient impact crater some 1200 km across that is found along the boundary separating the heavily-cratered southern highland terrain of Mars from the northern lowlands. Elements of both terrains are evident in this image as an island of rugged highland terrain surrounded by smoother lowland terrain. The resurfacing of the Isidis basin produced a system of wrinkle ridges, some of which are seen on the lowland terrain in the image. Wrinkle ridges are a common feature on the surface of the moon and add to the lunar-like quality of this image. Layers are visible in the large island, the most resistant of which likely are from lava flows that created the highland terrain. The process by which the global-scale highland/lowland dichotomy was created remains a mystery.