DIAMOND DUST SKI HALO: Ski resorts are one of the best places to see sun halos–rings of light that surround the sun when ice crystals fill the air. The most sublime halos are caused by jewel-like crystals called “diamond dust.” On Jan. 29th, Christian Schartner was skiing in Obertauern, Austria, when he witnessed this specimen:

“The outside temperature was quite chilly at -12°C when we hit the slopes,” says Schartner. “Beautiful sun halos made our skiing day even better!”

Most sun halos are caused by ice crystals floating high above Earth’s surface in cirrus clouds. “Ski halos,” on the other hand, are formed by ice crystals near the ground, kicked into the air by the action of skis and snow-making machines

fr/spaceweather.com