images

Sun Halo

by

Guillaume Blanchard/Novapix

Reference

t-met03-00027

Date

2009-02-02

Halos are caused by sunlight being refracted by cirro-stratus clouds. These are thin clouds, very high in the atmosphere, and are composed of ice crystals. They bend light at a 22 degree angle, which creates a halo around the sun that is 44 degrees in diameter.