Orcus Patera

"For the Electric universe, the cosmic thunderbolt is the mechanism of cratering on the planets and the moons of our solar system." -- Mel Acheson, natural philosopher, June 2005

"A sweeping revision is necessary, one that recognizes the predictable effect when a charged planet or moon moves through an electrified plasma. Where field strength is high, the result will be global electric discharge, as cosmic 'thunderbolts' rake across the surface, creating entirely new topography. Allow this possibility, and the exploration of solar system history is radically altered. Suddenly, plasma discharge and electrical arcing experiments (which have been excluded from planetary science) will be permitted to shed their light on thousands of features left unexplained by traditional theory. On every solid body in space, we have observed craters lacking any conventional explanation. In fact, on close observation, many craters show distinct features that are not associated with volcanic or impact craters, but are easily created by electric arcs in the laboratory and by electric discharge machining (EDM) used in industrial applications." -- Michael Goodspeed, journalist, December 2007

Physorg: Mars's mysterious elongated crater.

(PhysOrg.com) -- 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 1800 m above the surrounding plains, while the floor of the depression lies 400-600 m below the surroundings.

The term ‘patera’ is used for deep, complex or irregularly shaped volcanic craters such as the Hadriaca Patera and Tyrrhena Patera at the north-eastern margin of the Hellas impact basin. However, despite its name and the fact that it is positioned near volcanoes, the actual origin of Orcus Patera remains unclear.

Aside from volcanism, there are a number of other possible origins. Orcus Patera may be a large and originally round impact crater, subsequently deformed by compressional forces. Alternatively, it could have formed after the erosion of aligned impact craters. However, the most likely explanation is that it was made in an oblique impact, when a small body struck the surface at a very shallow angle, perhaps less than five degrees from the horizontal.

The existence of tectonic forces at Orcus Patera is evident from the presence of the numerous ‘graben’, rift-valley-like structures that cut across its rim. Up to 2.5 km wide, these graben are oriented roughly east-west and are only visible on the rim and the nearby surroundings.

Within the Orcus Patera depression itself, the large graben are not visible, probably having been covered by later deposits. But smaller graben are present, indicating that several tectonic events have occurred in this region and also suggesting that multiple episodes of deposition have taken place.

The occurrence of ‘wrinkle ridges’ within the depression proves that not only extensional forces, as would be needed to create graben, but also compressive forces shaped this region. The dark shapes near the centre of the depression were probably formed by wind-driven processes, where dark material excavated by small impact events in the depression has been redistributed.

However, the presence of graben and wrinkle-ridges has no bearing on the origin of Orcus Patera, as both can be found all over Mars. The true origin of Orcus Patera remains an enigma.