Moon with a ring in SemarangMarch 29, 2010 at 5:12 am | Posted in Nature | Leave a comment
Semarang people, did you look at the sky at Sunday, March 28, 2010 night? When you looked at the moon, you would see an unusual natural phenomenon. There was a wide ring around the moon. What was it? Some people relate it to myths. Some others relate it to religious matters. Some have their own interpretations toward this phenomenon.
However, what was that? It was halo effect.
Halo, phenomenon of light refraction caused by ice crystals in the atmosphere between the observer and the sun or moon. The commonest form of halo is a circle of colored light surrounding the disk of the sun or moon. Light from the sun or moon is bent by the atmospheric ice crystals at a 22° angle toward the observer. Thus, the halo is a circle with a radius 22° from the center of the disk. Sometimes, a secondary halo caused by the refraction from ice crystals is seen outside the primary halo at a distance of 46° from the center of the sun or moon. (Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.)
Here are some pictures I took with my digital camera, Nikon Coolpix L19.