Every once in a while, you look up into the sky and see what looks like a halo around the sun. Halos are an optical phenomenon that occur around the sun or the moon while there are very high cirrus clouds in the atmosphere. They can even be seen in very cold weather around street lamps or other artificial sources of light. (Learn more about sun halos and what causes them on CNN's This Just In blog »)
Have you ever seen a sun halo? Share your photos here, and be sure to include where and when you took them.

