Did you see the ring around the moon last night?

22-degree halos

VICTORIA, Texas- This fairly common phenomenon occurs when thin cirrus clouds, containing millions of tiny ice crystals, cover the sky. The ring is caused by the refraction of moonlight through the ice crystals suspended in the upper atmosphere at an altitude of about 20,000 feet. They are usually seen with cirrus clouds, thin wispy clouds at high altitudes.

The ice crystals have a similar hexagonal shape that act as a miniature lens refracting the light that enters the crystal. The light enters one crystal face and exits the opposing face refracting at 22 degrees, which corresponds to the radius of the halo around the moon.

These halos, which can also been around the sun, are often thoughts of to be harbingers of rain.

In conclusion, you’re not crazy. The ring you saw around the moon Thursday night was real and it happens more often than you think.