Saturday, July 16, 2011

Nature Video ~ Moonbows at Yosemite

Moonbows in Yosemite











A moonbow (also known as a lunar rainbow, white rainbow, lunar bow or space rainbow) is a rainbow produced by light reflected off the surface of the moon rather than from direct sunlight. Moonbows are relatively faint, due to the smaller amount of light reflected from the surface of the moon. They are always in the opposite part of the sky from the moon.

It is difficult for the human eye to discern colors in a moonbow because the light is usually too faint to excite the cone color receptors in human eyes. As a result, they often appear to be white. However, the colors in a moonbow do appear in long exposure photographs.

A true moonbow is lit from the Moon itself. A colored rainbow when the sun is setting or when it is darker out is not a moonbow because it is still produced by sunlight. Moonbows have been mentioned at least since Aristotle, in his Meteorology, circa 350 BC, and in 1847 and the term moonbow was used by Nick Whelan who sighted one of the first documented moonbows in Eastern Utah.