Ariadnes Colles, annotated nadir view

This image, taken by the Mars Express High Resolution Stereo Camera, show the region of Ariadnes Colles on the Red Planet.

The data was acquired on 16 April 2007 in the region of Ariadnes Colles that lies at about 34° south and 172° east. The ground resolution is about 13 m/pixel.

Ariadnes Colles is one such chaotic terrain located in the southern highlands of Mars. It covers an area of 180 x 160 sq km, roughly half the size of Estonia. The HRSC images show the northwestern part of the region.

Most of the area pictured is dominated by erratically shaped rocks that are 1-10 km in size (1). These are lighter in colour compared to their surroundings. Some larger blocks appear similar to mesa, a flat-topped natural elevation, and can reach a height of 300 m (2).

A striking lineation on the surface of the blocks (visible upon zooming in) (3) is oriented in the northwest-southeast direction. The northwestern flanks have been eroded more strongly than the opposing southeastern flanks.

Wrinkle ridges, which form as a result of tectonic compression, are visible in the southwestern part (4). These ridges mark the western boundary of Ariadnes Colles.

In contrast to other chaotic terrains such as Iani Chaos, Adrianes Colles is not a water source region. This is why it is still debated whether Ariadnes Colles formed by the action of water or wind.

The darker material in the southern parts is most likely sand or volcanic ash; some slopes of the flat-topped features have been covered by this dark material that was blown up on the slopes (5).

A large impact crater, 1200 m deep, is visible on the right (6). It shows a smaller crater superimposed on it. The larger crater is about 30 km in diameter and covers an area roughly the size of Hamburg. The smaller younger crater lies almost at the centre of the older one, and has a diameter of just 10 km.