Halo Around Roque Cinchado

As seen on the National Geographic News atmospheric halo around the sun as seen from Teide National Park, Tenerife, Spain. Large halo around the Moon or the sun occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens. Because most of the crystals have a similar elongated hexagonal shape, light entering one crystal face and exiting through the opposing face refracts 22 degrees, which corresponds to the radius of the Sun or the Moon Halo. In the foreground is the Roque Cinchado, a unique rock formation and is emblematic of the island of Tenerife (Canary Islands).