Orcus Patera is a region on the surface of the planet Mars first photographed by Mariner 4. Of unknown formation, whether by volcanic, tectonic, or cratering causes, the region includes a depression about 380 kilometres (240 miles) long, 140 kilometres (87 miles) wide, surrounded by a rim up to 1.8 kilometres (1 mile) high.
Orcus Patera was first imaged by Mariner 4.[1] It is a depression about 380 kilometres (240 miles) long, 140 kilometres (87 miles) wide, and about 0.5 kilometres (1⁄3 mile) deep but with a relatively smooth floor.[2] It has a rim up to 1.8 kilometres (1 mile) high.[2]
It has experienced aeolian processes, and has some small craters and graben structures.[2] However, it is not known how the patera originally formed.[2] Theories include volcanic, tectonic, or cratering events.[2] A study in 2000 that incorporated new results from Mars Global Surveyor along with older Viking data, did not come out clearly in favor of either volcanic or cratering processes.[3]
Mars Express observed this region in 2005, yielding a digital terrain model and color pictures.[2]
Orcus Patera is west of Olympus Mons and east of Elysium Mons.[2] It is about halfway between those two volcanoes, and east and north of Gale crater.
