The mysterious ridges at the mouth of Tiu Valles

This image taken by the High Resolution Stereo Camera on board Mars Express shows the mouth of the Tiu Valles channel system on the red planet. The picture was taken in orbit 3103 on June 10, 2006 with a ground resolution of approximately 16 meters per pixel. Visible in the lower part of the image are remnants of a once "streamlined" island. The upper part of the scene covers the mouth of the Tiu Valles nearly in its entire width, approximately 55 kilometers. Its winding, meandering ridges, bound by depressions are eye-catching. The processes that formed these odd structures are unknown. Possibly, during flooding events, water or water-rich surface layers came in contact with lava from the surrounding areas, which then might have led to the formation of these mysterious ridges. The region is located at approximately 27 degrees north and 330 degrees east. The sun illuminates the scene from the northwest, the lower left-hand side in the image. The color scenes have been derived from the three HRSC-color channels and the nadir channel. Credit: ESA/DLR/FU Berlin (G. Neukum)