Sometimes, you might even see hints of rainbow colors within the halo ... They can be mistaken for sun dogs: While sun halos form a full circle around the sun, a similar phenomenon called a ...

common halo around the sun, colored spots of light on either side of the sun known as "sundogs," an upper tangent arc and a rare circumzenithal arc that resembles an upside-down rainbow.

Hong Kong on Tuesday witnessed a rare natural phenomenon, a halo around the sun, that can be experienced only when meteorological conditions are right. The Observatory posted pictures on its ...