Oblong Martian Crater:Orcus Patera

Despite having first been observed in 1965 by the Mariner 4 spacecraft, planetary scientists remain uncertain as to the exact origin of the oblong crater on Mars dubbed, "Orcus Patera", seen in the above image from the ESA's Mars Express spacecraft. This 236 mile long formation is located on the planets equator, has a mile high rim, and it's floor lies between 1300 and 1900 feet below the surrounding terrain.

While the crater is situated between two volcanoes, Elysium Mons and Olympus Mons, and has been designated a petera -the name for irregularly shaped volcanic craters- scientists are not certain that Orcus has a volcanic origin. In fact, the most likely explanation for the crater seems to be from a small object striking the planet at a shallow angle like a rock skipping on the surface of a pond leaving the oblong shaped crater in it's wake.
-CAINE-

For more info, check out this article on Wired Science and go HERE to view the original article on the ESA website. Also, if you've never done so before then be sure to visit the ESA website and check out more images from Mars Express.

Image credit: ESA/DLR/FU Berlin (G. Neukum). More images available on the ESA website