Dear Tom,

The “Man in the Moon” feature on the moon’s surface has always fascinated me. What is it about the moon’s surface that creates the shading that resembles a human face?

Janice Longston

Dear Janice,

The “Man in the Moon” illusion on the face of a full moon is an example of pareidolia, the psychological phenomenon in which our brain interprets random images as something recognizable. Other examples of pareidolia are perceived images of faces or animals in cloud formations.

In the case of the moon, the darker appearing areas on the face of the full moon are thought to be huge lava-filled craters, now cooled, remaining from large asteroid impacts. Patches of darker terrain, called luna maria or seas, combine to form a human face. Eyes are the Mare Serenittis and Mare Imbrium. The nose is the Sinum Aestuum. The mouth is the Mare Cognitum and Mare Nubium.

The “Man in the Moon” pareidolia is an illusion in many cultures around the world, both past and present.