Looking up in the sky may be a favorite pastime of yours, and if so, you may have spotted a common winter phenomenon.
That small circle of rainbow next to the sun is not actually a rainbow. Well, it is a prism of light of sorts, but it occurs when sunlight mixes with cirrus or cirrostratus clouds and ice crystals. This phenomenon is called a sun dog. It is closely related to a sun halo.
They are very common throughout the winter months because of the cold air aloft that allows the freezing of moisture in the clouds.
