photos of 22º radius halos, which occur as the light from the sun or the moon, usually when close to the horizon, pass through thin, hexagonal plate shaped ice crystals high up in cirrus clouds. also shown are parhelia (or sundogs) and paraselenae (or lunar parhelic/snowdogs, as seen in the fourth and seventh images.) the first and second photos also show the 46º halo and tangent arc, with the latter showing the parhelic circle as well, while the eighth photo shows a sun pilar. (learn more)
photos by (click pic) sean davies, sebastian saarloos, sverrir thorolfsson, steve nilsen, norbert rosing, chee, stringer, china news, david cartier and svein nordrum.