For two hours, residents of the Chinese city of Harbin enjoyed an unusual spectacle: a parhelion produced by the accumulation of ice crystals in the atmosphere.
The hexagonal crystals reflect sunlight which creates an optical effect showing a halo with three bright spots: In the center lies the true sun, and on either side its reflection on the ice of the clouds.
For the phenomenon to occur for so long, the atmospheric pressure must be stable, the temperature cold and the necessary amount of moisture and clouds accumulated.
