UFO watchers' eyes were set ablaze recently by reports of what looked like a stony rodent lurking among the rocks on Mars. The so-called Mars rat, spotted in an image taken last year by the NASA rover Curiosity’s Mast Camera, captured imaginations even as it inspired several new parody Twitter accounts.
But, just so it's clear, this Red Planet rodent – which looks rather more like a guinea pig to this reporter’s eye – is no more real than the Man in the Moon. In fact, the rat likely comes from the same source as that lunar visage: the human brain.
Humans experience a phenomenon known as pareidolia, which is the tendency to distinguish animals, faces or other significant images in otherwise inanimate objects. This ability to pick out faces quickly is likely a product of evolution, as Carl Sagan explained in "Demon-Haunted World: Science as a Candle in the Dark."
“Those infants who a million years ago were unable to recognize a face smiled back less, were less likely to win the hearts of their parents, and less likely to prosper,” Sagan wrote.
But one side effect of this otherwise beneficial ability is that humans sometimes see things where they are not. In this case, it makes the “rat” almost impossible to ignore.
For those thinking it means that Earthlings have been sending critters to Mars, keep in mind that introducing foreign species to a planet’s native environment is taken seriously, as the controversy around Curiosity’s potentially microbe-contaminated drill bits shows.
Also, humans recently appeared to have had some trouble sending animals into low-Earth orbit.
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