images

Lunar Halo and Moon dog

by

Sauli Koski/Novapix

Reference

t-met03-70012

Date

2012-03-11

Lunar halos are caused by moonlight being refracted by cirro-stratus clouds. These thin clouds are located very high in the atmosphere, and are composed of ice crystals. They bend light at a 22 degree angle, which creates a halo that is 44 degrees in diameter. Glowing patches on the right and left at the Moon's elevation are named Moon dog. Moon dogs are the same phenomenon as the sun dogs for the Sun. Finland.