Libya Montes Valley
The HRSC obtained this image on 7 October 2004 during orbit 922 with a ground resolution of approximately 14.3 metres per pixel at equatorial latitudes near longitude 81° East. North is up.
The image shows the central reaches of a 400-kilometre long valley that was carved into the surface in early Martian history, approximately 3500 million years ago.
The central parts of the broad valley show traces of an interior valley, documenting the flow of water that once occurred on the surface of the planet during periods of wetter climate.
Determinations of discharge volumes on the basis of high-resolution HRSC derived digital terrain models reveal discharge rates that are comparable to those of the middle reaches of the Mississippi river in the USA.
Based on crater-size frequency distributions on the valley floor and surrounding terrain it has been shown that the formation time of the valley is about 350 million years.
Measurements of erosion rates suggest that the active phases of valley development are characterised by short periods of intense fluvial activity rather than sustained liquid flow.
Details on valley formation have been published by R. Jaumann (DLR) et al  in the article "Constraints on fluvial erosion by measurements of the Mars Express High Resolution Stereo Camera" in Geophysical Research Letters, 32, L16203, doi:10.1029/2005GL023415.
The colour scene is derived from the three HRSC colour channels and the nadir channel.
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