The European Space Agency (ESA) has released new images of Orcus Patera (at right), an enigmatic elliptical depression near Mars’s equator. Orcus Patera is located between the volcanoes of Elysium Mons and Olympus Mons, in the eastern hemisphere of the planet.
The relative location can be seen in this map from Google Maps Mars: Orcus Patera is to the right of Elysium Mons (in the center of the map) and left of the huge Olympus Mons. To the right of Olympus Mons is the Tharsis Plateau.
The feature is about 380 km from South to North, and 140 km in the East to West direction. The rim rises up to 1800 m above the surrounding plains, and the floor of the depression is between 400 and 600 m below the plains.
The most likely explanation for the formation is an impact by a small body at a very low angle. The ESA scientists suggest it was perhaps only five degrees. The impact would have gouged out the furrow, much like Superman’s spaceship did on the Kent farm.
Another explanation involve a series of impact craters that overlapped and then eroded into each other. This requires the good fortune that craters were in alignment and progressed form small in the South to large in the North.
The article discusses the possibility that there was an original round crater, which was later compressed along the East-West axis. There are visible tectonic features in and around the feature.
Vulcanism is a possibility, as the feature lies between two large volcanoes. The term ‘patera’ is used for deep, complex or irregularly shaped volcanic craters, although this seems the least likely method of formation.
Interestingly, no mention of the age of the feature was made. The region outside Orcus Patera seems fairly heavily cratered, while the floor inside the basin seems quite smooth, with only a couple of small craters. This might suggest the feature is relatively young.
Let us know what you think. What do you want to know about? Post a comment.