Libya Montes Valley on Mars

ESA’s Mars Express took this photograph of Libya Montes, which is south of the large Isidis Planitia impact basin on Mars. The region contains a 400 km (248 mile) long valley that was carved into the early Martian surface; probably by water when the planet was warm and wet. Scientists estimate that the same amount of water was probably flowing out of the region as middle reaches of the Mississippi river in the US.

These images, taken by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express spacecraft, show the region of Libya Montes, south of the Isidis Planitia impact basin on Mars.

The HRSC obtained these images during orbit 922 with a ground resolution of approximately 14.3 metres per pixel at equatorial latitudes near longitude 81 degrees East.

The images show 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.

On the basis of crater-size frequency distributions on the valley floor and surrounding terrain it has been shown that the formation time of the valley amounts to approximately 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) and colleagues, as an 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).

***image4:right***The colour scenes were derived from the three HRSC colour channels and the nadir channel. The perspective views have been calculated from the digital terrain model derived from the stereo channels.

The 3D anaglyph image was calculated from the nadir and one stereo channel. The black and white high-resolution images were derived from the nadir channel that provides the highest detail of all the channels.

Original Source: ESA Mars Express