Halo Around the Sun

Written by: Stacey Pensgen

A viewer recently sent us an email asking about a "rainbow ring around the sun." This is actually a fairly common phenomenon in meteorology. It is called a corona, or a "halo around the sun." It's usually visible when cirrus clouds are present. Sunlight is reflected and refracted by the ice crystals in the clouds, and forms a ring around the sun.

This can also be seen around the moon at night. So, the next time we've got a little milky cirrus action going on in the sky, look up and you may see a little surprise!