Iridescent Pac-Man Cloud

Christine Irakleous
Location of photo
Thessaloniki, Greece
Date/Time of photo
25 April 2016
Canon 600D
The phenomenon presented in this photo is called Irisation or Cloud Iridescence (from Iris, the ancient Greek godess which was the personification of the rainbow). It is a fairly uncommon phenomenon and it appears when tiny ice crystals or water droplets are present in very thin (semi-transparent) clouds. The light from the moon is diffracted on the droplets causing rainbow colours to appear in the clouds. Larger ice crystals produce the phenomenon known as lunar (or solar) halo. This picture was taken on a cold cloudy night in Greece. The red "star", below the moon and the iridescent Pac-Man cloud is the planet Mars.