Russell Penner, age 7, of Gleichen, Alberta, Canada, for his question:

What brings out the sun dogs?

Sun dogs are lovely pale pictures that appear in the sky. Usually they look like a pair of baby sunlets, one on each side of the big sun. Actually they are just a few miles above our heads    and the real sun is 93 million miles away. But let's never, never stare straight at the sun dogs because the rays of the real sun can damage our eyes. This can happen, even when the sun hides behind a veil of clouds.

Sun dogs don't come out very often because the air above the ground must be just right. A mile or two above our heads there must be a very thin veil of tiny crystals of ice. Sunlight from the sun must pass through this gauzy veil on its way to the ground. And those tiny ice crystals play all sorts of tricks on the sunbeams. They act like zillions of mini mirrors and scatter bits of sunlight off in different directions. Sometimes the ice crystals and sunbeams team together to make sun dogs appear    and disappear.