*** THIS PICTURE MAY NOT BE USED TO STATE OR IMPLY ESA ENDORSEMENT OF ANY COMPANY OR PRODUCT *** Martian canyon rim. Mars Express perspective view of the rim of the Melas Chasma (Melas Canyon) on Mars. The walls of the canyon are many kilometres high, larger than the Grand Canyon on Earth. This area is many kilometres wide. Collapse and erosion features are clearly seen on the canyon wall, and it is thought that water once flowed in this area. Melas Chasma is part of the enormous Valles Marineris (Mariner Valley) canyon system on the Martian equator. Data from the High Resolution Stereo Camera. Mars Express has been orbiting Mars since December 2003.