Do you know the phenomnon that caused the Halo kind of Ring around the moon yesterday??
http://www.atoptics.co.uk/ That is called a Moon Halo. It is caused by the light of the moon reflecting off of tiny ice crystals high in our atmosphere. Check out the above site called Atmospheric Optics and you can see some incredible photos of Moon Halos and Sun Halos too along with a lot of other things that happen in our sky. Enjoy!