Lunar Halo - Lunar and solar halos are caused when light passes through ice crystals formed in clouds through the sky. Credit: Shingo Takei There was a lunar halo the other night and I was a bit intriqued by it.
A halo develops when light enters one side of a columnar ice crystal and exits through another side. The light is refracted when it enters the ice crystal and once again when it leaves the ice crystal.
Halo cause by ice in the upper atmosphere. The clouds are called Cirrostratus.~ A very rare and beautiful photo of a circular rainbow over the salt marshes of Bolivia :) Yuri Pustovoy (c-man) Photographer