Halo from Vallentuna, Sweden
December 29, 2006
The above photo showing a glorious 22 degree solar halo was captured from Vallentuna, Sweden in February of 2006. I was out with my children in our backyard when this fantastic ring of light took shape. As I grabbed for my old camera, I noticed that a condensation trail (contrail) had bisected the halo. The 22 degree halo forms in cirrus clouds composed of hexagonal (pencil-shaped)ice crystals having non preferred orientations. Refraction and reflection of sunlight throught these crystals produces a circle of light 22 degrees in radius.