From rats to skulls to a disappearing doughnut, so-called "ufologists" claim to have seen all sorts of strange things in photos taken by NASA's Curiosity Mars rover.

Now they're saying that a rover photo taken in 2012 (see below) shows the shadow of a human or human-like alien "messing with" the rover.

"The person has no helmet and their short hair is visible and in high detail," Taiwan-based ufologist Scott Waring wrote in a post on his blog UFO Sightings Daily . "The person has on air tanks on their back and a suit that covers most of the body except the hair."

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Waring goes on to wonder if the image indicates that the rover isn't on Mars at all but right here on Earth--or that humanoid aliens live on the Red Planet.

Of course, there's always the (more likely) possibility that the shadow only looks like that of a human form. It makes sense that our brains would interpret the image this way. Humans are wired to spot patterns and even faces in images--it's a phenomenon called pareidolia .

Here's the same shadow from a slightly different angle taken about 28 seconds later. Yes, it still looks vaguely like a person. But if it is, "he or she" managed to keep perfectly still, because the figure hasn't budged even slightly.

Our verdict? It's just the rover's own shadow.