Orcus Patera is an enigmatic elliptical depression near Mars’s equator, in the eastern hemisphere of the planet. Located between the volcanoes of Elysium Mons and Olympus Mons, its formation remains a mystery. Often overlooked, this well-defined depression extends approximately 380 km by 140 km in a NNE-SSW direction. It has a rim that rises up to 1 800 m above the surrounding plains, while the floor of the depression lies 400-600 m below the surroundings.
Credit: ESA/DLR/FU Berlin (G Neukum)