Chaotic terrain in Iani Chaos

Chaotic terrain in Iani Chaos

17 July 2006

These images, taken by the High Resolution Stereo Camera (HRSC) on board ESA's Mars Express spacecraft, show Iani Chaos, a region east of Valles Marineris characterized by a disrupted and chaotic appearance, similar to other so-called 'chaotic terrain' on Mars.

Map showing Iani Chaos in context

The HRSC obtained these images during orbit 945 with a ground resolution of approximately 13.0 metres per pixel. The images show the region of Iani Chaos, lying at approximately 0.7° South and 340.6° East.

Iani Chaos is one of many regions east of Valles Marineris characterized by disrupted or chaotic terrain. The morphology of this terrain is dominated by large-scale remnant massifs, which are large relief masses that have been moved and weathered as a block. These are randomly oriented and heavily eroded.

Iani Chaos, perspective view
Perspective view of Iani Chaos

To the south (to the left) in the colour image, these mesas, which appear as flat-topped hills, range from less than one kilometre to roughly 8 kilometres wide, with a maximum relative elevation of approximately 1000 metres.

The relatively flat region in the north-west (upper right) of the colour image exhibits a number of faint, circular depressions. These depressions, along with the remnant massifs, may have been formed by collapse of the surface due to the removal of underlying material, for example ice or water.

Iani Chaos, black and white (north to the right)

Scientists believe that Iani Chaos was the source of the fluids thought to have created Ares Vallis, the roughly 1500-kilometre-long valley that extends to the north-west in the direction of Chryse Planitia.

The colour scenes have been derived from the three HRSC-colour channels and the nadir channel. The anaglyph image was calculated from the nadir and one stereo channel. Image resolution has been decreased for use on the internet.

Iani Chaos, 3D anaglyph

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