The Face on Mars
The account
A NASA photo supposedly shows a giant face carved on Mars, surrounded by pyramids, the remains of a lost civilization.
What investigators found
Sharper photos in the following decades revealed an eroded hill. The "face" was an effect of light and shadow in a low-resolution image.
The story
On July 25, 1976, NASA's Viking 1 orbiter photographed the Cydonia region of Mars while searching for a landing site. In one of the images, a hill about 2 kilometers across looked like a human face gazing at the sky. NASA itself released the photo, remarking on the resemblance.
The image became a symbol of theories about a Martian civilization, with supposed pyramids nearby. In 1998 and 2001, the Mars Global Surveyor photographed the site in far greater detail, and other spacecraft later did the same: it was an ordinary hill, worn down by time. It is a famous example of pareidolia, the brain's tendency to see faces in everything.