Have you ever looked up and spotted a ring around the sun?
This optical phenomenon is called a 22-degree halo.
That's because the radius of the halo is approximately 22 degrees.
So how are they formed?
The halos are caused by the refraction of sunlight through tiny ice crystals in the atmosphere associated with thin, high-level cirrus clouds
Those thin cirrus clouds are around 20,000 feet or higher above us. They are made of tiny, ice crystals. Sunlight through the ice crystals causes the light to split, or be refracted. When at just the right angle, it causes us to see the halo. pic.twitter.com/kG5Qi7oDeG
— Dave Hovde (@tvdave) May 12, 2022
22-degree halos are commonly seen around the moon, as well.
