What is a “Moon Ring”?

21 August 2014

The Short Answer (TSA)

            A ring of soft light or luminescent ring sometimes forms around the Moon on dark nights.  This “halo” is caused by the Moon’s light passing through millions of ice crystals high in the atmosphere. 

            Traditionally, a ring around the Moon meant that storms were on the way.  And, in fact, a ring often appears when the Moon can be seen through a thin layer of clouds covering the sky.   The thin layer is made up of cirrus clouds, which often do come a few days before a storm front.

            Because of the shape of the ice crystals, rings form a circle around the Moon that is always about 22 degrees away from the Moon itself.  How far is 22 degrees?  Well, looking up in the sky, extend your arm toward the Moon and look at the size of your hand.  That’s about 22 degrees.

M Grossmann of Hazelwood, Missouri
(& Belleville, Illinois)
About the Author
21 August 2014