There’s simply nothing on all of Mars quite like it: Orcus Patera, a long, elliptical Martian depression situated between two sibling volcanoes, Elysium Mons and Olympus Mons, is a nearly 235-mile-long anomaly. Especially on its furthest side (far right in the image above), a rim protrudes from the depression, rising nearly to an elevation 6000 feet above the surrounding plains. According to the European Space Agency (ESA), the use of “patera” in the strange crater’s name denotes a complex or irregularly shaped formation. “However, despite its name and the fact that it is positioned near volcanoes, the actual origin of Orcus Patera remains unclear,” the agency states at their website.
There has apparently been a good bit of speculation as to what might have caused the appearance of this strange anomaly, and Friday, the latest answer ESA officials provided only lends itself to more controversy:
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.
This mention of a “small body” seemed to fuel imaginative speculation as to what sort of an object might have been the culprit. Lewis Page, writing for The Register this morning, said “Plainly, we’re talking here about an alien spaceship, its propulsion crippled, attempting a very-high-velocity glide landing through the evanescent Martian atmosphere–and cocking it up.” But if this were the case, could there still be debris located nearby? “There has to be a sporting chance,” Page continued, ruminating over whether “the alien ship yet lies preserved within its eternium-powered force bubbles, sealed within the now-cooled lake of molten rock it created as it crashed.”
So far as an actual solution to Orcus Patera’s strange shape, it seems we may be dealing with an area of the Maritan surface where an object (more likely a meteorite) entered the planet’s atmosphere at an angle that allowed it to glance the surface, possibly scraping by only to ricochet back into space again. Thus, the long lasting “alien skid mark” remains, decorating Mars with yet another strange, yet curiously wonderful natural landmark.
Image courtesy of ESA archives.
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So that’s where ALH84001 came from….
There are ground markings like that in South America (Chile, Argentina perhaps)? Where at some point in the past a meteorite or suchlike has hit the earth obliquily and caused a series of scars across the landscape.