An alien spaceship crash landing cannot be ruled out as the cause of the strange pointy protrusions found on Mars, scientists have said.
In April, Nasa’s Curiosity Rover photographed what appear to be rows of spikes, plates and wedges protruding from rocks on the floor of the 96-mile (154 km) Gale Crater.
At the time, astrobiologist Dr Nathalie Cabrol, of the Nasa Ames Research Centre and Search for Extraterrestrial Intelligence (Seti) Institute, said it was “the most bizarre rock” she had ever seen in 20 years of studying Mars.
Now, a new paper published in the Journal of Astrobiology concludes that the formations might be “sand spikes”, similar to those known to form on Earth in water-logged sands during strong earthquakes of magnitude seven and greater.
Similar rock formations have been found at the north Alpine basin of south Germany, associated with the 15 million year old Nordlinger Reis asteroid impact basin, and at Mount Signal in the Imperial valley of southern California, close to the San Andreas fault.
But researchers caution that “a fragment from an extraterrestrial or terrestrial spacecraft cannot be discounted with absolute certainty” – pointing out that what appear to be wheels, an axle and a debris field have been photographed in another part of the Gale Crater.
A similar debris field connected to the spikes may have been eroded over time, said the authors.
Prof Richard Armstrong, of Aston University, Birmingham, who is first author of the paper, told The Telegraph: “There is no way of proving for certain what the spikes are but the balance of the evidence would suggest ‘sand spikes’ resulting from seismic activity on Mars.
“I suspect the enigmatic ‘wheels’ are a separate phenomenon. Mars images often show strange formations and features which ‘look like’ familiar objects.”
But he added: “Any debris field on Mars would certainly suffer erosion over time, especially from wind.”
In the images taken by Curiosity, at least six rocks are shown with strange protrusions, including one with 11 evenly spaced spikes.
Wedge-shaped objects resembling shark teeth can also be seen below the spikes, as well as plates or boards that appear to have embedded spikes.
Objects ‘unlikely to be from human craft’
Previously, it was speculated that the strange objects were fossil fish bones, dinosaur bones, or caused by weathering through Martian winds.
Many suggested that they could be the remnants of a crashed Mars orbiter or discarded equipment.
Pieces of landing modules, such as heat shields or parachutes, are often jettisoned on the way down to the surface. They can break into smaller pieces and be blown around by Martian winds.
At least 10 spacecraft have crashed or lost contact on Mars, including Britain’s Beagle 2.
Even bits of the Curiosity Rover have fallen off as it has trundled over the Red Planet. Experts estimate there are now 15,694lbs (7,119kg) of human debris on the surface.
But, in the new paper, experts say it is unlikely the strange objects were linked to human craft because they do not look like anything sent from Earth.
Writing in the journal, the authors say: “Given that possibly 10 or more craft have crashed upon the surface, coupled with the jettison of equipment associated with landing the rovers, it is possible the spikes and its substrate are human-made and consist of debris that fell onto the surface of Gale Crater.
“Nevertheless, no debris field is evident and no evidence of any additional debris that may have originated on Earth.
“Given its small size and that there are no known human-made analogs and no logical explanation as to what purpose these spikes may serve, it does not seem likely these specimens are the remnants of craft or equipment that fell into Gale Crater.
“One can only speculate about extraterrestrial origins.”
The team say although “sand spikes” are a plausible explanation, the Martian protrusions do not have the same bulbous ends as spikes on Earth.
Unlike Earth spikes, Martian spikes are also sometimes serrated.
The experts say the spikes could also be linked to activity by tiny microorganisms on Mars, because they are close to features reminiscent of fungi or microbialites – layered rocky structures formed by communities of microbes.
They may also be the remains of petrified algae or trace fossils, such as sand-filled worm burrows.
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