Lunar Halo & Aurora Norway
22º halo image index
Lunar halo and aurora. Imaged in Norway by Arne Danielsen (astrophotography and atmospheric phenomena) during the great auroral display over Europe on 21st January 2005. The ice crystals of the thin cirrus layer that created the halo are well below the glowing atoms of the aurora. The Pleiades and Taurus are to the right of the moon, Castor and Pollux to the left and Saturn lower left.

The moon was high in the sky when this image was taken. Whenever the sun or moon is high and a circular halo is seen, it could be a circumscribed halo produced by horizontal columns rather than a 22º halo made by poorly oriented crystals. The two are not easy to distinguish but the circumscribed halo is slightly sharper with brighter colours -- it is usually also accompanied by a parhelic circle. This one looks like a 22º halo.