On Tuesday night, many WNDU viewers called or emailed to ask about the large ring around the moon.
What they were seeing was a moon halo.
The halo formed due to the refraction of moonlight by ice crystals in the high, thin clouds that were in the sky.
More specifically, light enters the ice crystals on one side, but then slows down as it travels through the ice, and is then refracted 22 degrees, which is the radius of the halo.
Photo taken by Alec Hosterman.