The largest layered mound in Juventae Chasma is seen here in close-up perspective view. It is about 53 km long, up to 20 km wide and rises some 3.3 km above the surrounding area, comparable to a small mountain range on Earth.
Its surface is etched with grooves carved by strong prevailing winds blowing through the chasma. Layers in the mound consist of sulphate-rich materials, an indication that the rocks have been altered by water.
The mound is a relic of at least 3 billion years of martian history and its layers were most likely built up as lake deposits over time. But ice-laden dust raining out from the atmosphere – a phenomenon observed at the poles of Mars – may also have contributed to the formation of the layers.
This region was imaged by the high-resolution stereo camera on ESA’s Mars Express on 4 November 2013 (orbit 12,508), with a ground resolution of 16 m per pixel. The image centre is at about 4°S / 298°E.