The Face on Mars

The Face on Mars is one of numerous mesas located in the Cydonia region of the red planet. In a photo taken by NASA's Viking 1 on July 25, 1976, the formation was observed to resemble a human face, stirring up a relatively large amount of interest at that time. Several people believed that it was evidence of another civilization or some sort of ruined city.

( Can you spot the Face ? )

However, a much higher resolution image taken by the Mars Global Surveyor in 2001 reveals a natural looking Martian Hill, similar to the many other mesas present in that region. This suggests that the face-like illusion observed is dependent on both the viewing angle and the angle of illumination, since the facial features are largely created by shadows.

Another interesting feature on Mars is the crater named Galle, located on the impact basin Argyre Planitia. Also first observed from photos taken by the Viking 1, it took a backseat due to all the interest generated by the more humanoid Face in Cydonia.

Galle is also known as the 'happy face crater' as the illusion of a smiley is created by the mountain range and 2 smaller craters located within it.