The Face on Mars
One of the most iconic illusions came in 1976 when NASA’s Viking 1 probe captured the Face on Mars in the Cydonia region. NASA described the feature as a “huge rock formation…which resembles a human head…formed by shadows giving the illusion of eyes, nose and mouth.”
Naturally, some people interpreted this apparent face, which measures nearly 2 miles long, as a monument from a long-lost Martian civilization. Subsequent photos of the feature revealed it to be a mesa—basically an unremarkable flat-topped hill. The Face on Mars is now used as a classic example of pareidolia, a psychological phenomenon in which we project faces and other familiar things onto otherwise inanimate and mundane objects.
