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Chaos on Mars
Posted: November 10, 2009

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This stunning new image of Mars, captured by the European Space Agency’s Mars Express probe, shows the boundary between the fragmented Sacra Fossae region and the flat plains of Kasei Valles, which is one of the largest ancient outflow regions on the red planet.

The three-dimensional view of the terrain at the boundary between a flat, outflow region called Kasei Valles, and the fractured landscape of Sacra Fossae. Image: ESA/DLR/FU Berlin (G Neukem).

We can only see part of Kasei Valles in this picture – in total it is an enormous channel that spans 3,000 kilometres, running from Echus Chasma in Mars’ southern highlands to Chryse Planitia in the northern lowlands, and once upon a time ferried water between the two regions.

Notable in the picture is an old, worn crater that is 35 kilometres in diameter, which has been eroded by the ancient running water. The flatness of the plains and the crater floor is thought to be caused by volcanic lava flows from the Tharsis volcanoes.

A two-dimensional view of the terrain as seen from orbit. Image: ESA/DLR/FU Berlin (G Neukem).

Sacra Fossae, on the other hand, is broken, jumbled and chaotic, not just from water erosion that dissolved sub-surface rocks causing the overhead layers to collapse, but also from tectonic forces that plagued the land long ago. The large chunks of land still intact between the deep gorges have experienced subsidence, compacting the sub-surface layers. As a result this region, which is located at 12 degrees north and 285 degrees east and covers an area 225 x 95 kilometres, is one of the most fascinating yet imaged by Mars Express, which creates three-dimensional images of the terrain using its High Resolution Stereo Camera.