It's shiny. It’s sharp. It’s on Mars. It must be aliens! What appears to be a chunk of metal photographed by the Opportunity Rover has UFO buffs in a spin.

The high contrast infra-red image, published by the Mars Exploratino Rover Mission (Opportunity: Panoramic Camera: Sol 348) was uploaded by the Opportunity Rover on March 17.

It shows an unusually shiny, and jagged, object sitting neatly on top of the grainy surface of Mars’ Meridiani Planum.

It has internet chat forum Reddit in rapture.

“Uh NASA? UFO Caught on Mars Rover Mission? Is this real?” posted Prosaic Origin.

If it looks odd, of course it must be aliens!

But at least in this case the resolution is reasonably crisp. Not a blurry morass like most UFO ‘evidence’.

“Looks like light glimmering off of a genuine spaceship on an alien planet in outer space,” one commentator noted.

But, for that to be true, there’s the small matter of scale. At that distance from the Opportunity Rover, any inhabitants would probably have to be no larger than ants.

A more down to Earth (though admittedly this is Mars we’re talking about here) suggestion was that it could be a piece of debris from the rover itself, or a heat shield from the craft that delivered it.

Earthly trash is increasingly common on the Red Planet, especially after a string of mission failures in recent decades. Satellites have gone awry. Landers have crashed.

But even successful projects litter the landscape with debris as they plough through the thin atmosphere.

And Opportunity has been travelling back along the line of its lander’s approach. It has photographed discarded bits and pieces before.

This photo is just the latest in a long list of odd objects that have caused excited viewers to fall foul of the phenomenon of pareidolia.

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Essentially, they’re seeing what they want to see because of the way the human mind always tries to find familiar patterns among odd shapes.

Such as rabbits in clouds.

Or secret Nazi moon bases.

Or faces on Mars.

Or Martian hieroglyphs.

Or itsy, bitsy, incy wincy tiny alien spacecraft.