Unexplained Mysteries - The Face on Mars

The "Face on Mars" is one of the great modern mysteries about Mars. The "Face" first came to our attention 22 years ago, and debate about what it is has raged ever since.

The Viking spacecraft reached Mars in July of 1976. It had two missions. One was to send a lander down to inspect the surface of Mars. The other was to orbit the red planet, within a 1,000 miles of the surface, and take thousands of pictures to help to determine the best landing site for the Viking 2 spacecraft due to reach Mars in a few weeks.

On July 26, 1976, during Viking 1's thirty-fifth orbit of Mars, a set of photographic images arived at the Jet Propulsion Laboratory in Pasadena, California. One of the photographic frames, taken in the northern desert Cydonia region, showed a mile long, 1,500 mesa that looked like a humanoid face.
Cydonia Mensae is an albedo feature (region) on Mars.

The Cydonia Region taken by the Viking 1 orbiter and released by NASA/JPL on July 25, 1976 (north is to the upper right).

Some commentators, most notably Richard C. Hoagland, believe it to be evidence of a long lost Martian civilization along with other features they believe are present, such as apparent pyramids, which they argue are part of a ruined city. Image analysis of the early Viking images led a few researchers to suggest that the features of the Face might not be an accidental consequence of viewing conditions.