1 year ago
Last edited at 11:03PM on 12/24/2012
Many think it is a sign of rain.There's an old weather saying: ring around the moon means rain soon. There's truth to this saying, because high cirrus clouds often come before a storm. These circles, aka "halos" are a sign of high thin cirrus clouds drifting 20,000 feet or more above our heads.These clouds contain millions of tiny ice crystals. The halos you see are caused by both refraction, or splitting of light, and also by reflection, or glints of light from these ice crystals. The crystals have to be oriented and positioned just so with respect to your eye, in order for the halo to appear.