Ever seen a Moon dog?
When the Moon is low in the sky, a bright "false Moon" (a well-defined saucer of brilliant moonlight) may hover off to its side.
Sometimes, these "saucers" are distinct bright spots attached to a halo around the Moon at a point 22° to its right or left—or both sides at once. Often, however, they may seem to appear without the halo.
By day, with the Sun, one of these phenomena is called a parhelion, or sun dog. By night, it is called a paraselene, or Moon dog.
Look for a Moon dog when you see high, thin, cirrus clouds near the Moon.
Photo of Sun Dog by Donna Winsted