Face on Mars
The Face on Mars is a hill in the Cydonia region that, in a 1976 image taken by the Viking 1 probe, showed a formation resembling a human face. According to later, higher-resolution images, it is a natural formation.
The Face on Mars is a mesa (flat-topped hill), roughly two kilometers long, in the Cydonia region of Mars; an image of it taken by NASA's Viking 1 spacecraft in 1976 showed a formation resembling a human face. The image quickly became well known and turned into one of the most frequently cited examples in UFO literature.
What its proponents claim
In 1979–1980, computer specialists Vincent DiPietro and Gregory Molenaar found a second Viking image and analyzed the formation using image processing. In the 1980s, Richard C. Hoagland became the best-known advocate of the topic, mainly through his 1987 book The Monuments of Mars. According to proponents, the face and other formations visible in its vicinity, such as the features they call the “city” and the “pyramid,” are artificial structures, the remains of a destroyed Martian or extraterrestrial civilization. In their view, NASA is suppressing or misrepresenting the data that supports this.
Official and skeptical position
When the original image was released, NASA already stated that the effect was a play of light and shadow: the low position of the Sun and the image's poor resolution make us see the hill as a face. Skeptics regard the phenomenon as an example of pareidolia, that is, the human tendency to recognize familiar shapes, especially faces, in random patterns.
The question was settled by later images. Mars Global Surveyor in 1998 and 2001, ESA's Mars Express probe in 2006, and NASA's Mars Reconnaissance Orbiter in 2007 took far more detailed images of the region. In these, the formation is a natural, eroded hill without features resembling a face.
Significance
Today the Face on Mars is known more as a textbook example of pareidolia and image interpretation, and as part of popular culture.