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Moon Dogs

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Photo Credit
Matin Turner

The False Moon Phenomenon

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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. This is known as a Moon dog!

What is a Moon Dog?

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.

moon dog over the horizon
Photo of Moon Dog
Photo of Sun Dog by Donna Winsted


About The Author

Bob Berman

Bob Berman, astronomer editor for The Old Farmer’s Almanac, covers everything under the Sun (and Moon)! Bob is the world’s most widely read astronomer and has written ten popular books. Read More from Bob Berman

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