Orcus Patera keeps the experts guessing Photo Credit/ESA/DLR/Fu Berlin
The European Space Agency's Mars Express orbiter has imaged an alien geological mystery, an elliptical depression called Orcus Patera that stretches between the volcanoes Olympus Mons and Elysium Mons, near the equator in the Red Planet's Eastern Hemisphere.The depression stretches more then 230 miles and bulges to a width of 85 miles.
Most likely, Orcus Patera was carved from the terrain by an impactor striking at a shallow angle that must have been quite a sight as it struck.
Nonetheless, Martian experts have not ruled out volcanism as the origin of a feature that has been creased by tectonics and weathered by the wind. A rocky rim that rises more than a half-mile above the surrounding terrain deepens the mystery. The crater floor dips more than 1,200 feet below the landscape.