Ma'adim Vallis is one of the largest outflow channels on Mars. It is about 700 km long which is significantly larger than Earth's Grand Canyon. It is over 20 km wide and 2 km deep in some places. It runs from a region of southern lowlands thought to have once contained a large group of lakes(Eridania Lake) north to Gusev crater. Because it appears that water may have collected in Gusev crater, forming a giant lake; the Spirit Rover was sent there to investigate that possibility. However, only volcanic rocks were found on the floor of Gusev. Any lake deposits were probably covered over by a later deposit of volcanic materials from Apollinaris Mons, a nearby volcano, just to the north.
Ma'adim Vallis is in the Aeolis quadrangle at 21.8 S and 182.7 W. The word means Mars in Hebrew.
Ma'adim Vallis is thought to have been carved by flowing water early in Mars' history.
- Maadim Vallis.JPG
Section of Ma'adim Vallis as seen by HiRISE. A more recent flow of water may have formed the smaller, deeper channel to the right.