The ring is actually an optical illusion. It is caused when the moon light refracts off ice crystals in a thin veil of cirrus clouds. Those crystals create a giant lens 20,000 feet above us. They're ...

Moon halos are more likely to appear on a cold, winter night. The opposite, sun halos or solar halos, appear during the day time. What’s The Weather Connection? Cirrus clouds form about 20,000 ...