This February 2003 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows a valley in the Phlegra Dorsa region of Mars near 26.3°N, 186.2°W. The valley might have formed by flowing water or lava, but very little is yet known about this valley---where is its source? where does it end? The valley is intimately associated with lava flows, and might therefore result from volcanism rather than water. The fluid responsible for the valley moved from the lower left (southwest) toward the upper right (northeast). The picture covers an area 3 km (1.9 mi) wide. The scene is illuminated by sunlight from the left.

All Images Credit: NASA/JPL/Malin Space Science Systems