Sunday, June 03, 2007
The LA Times recently printed this spectacular photo of a moonbow over Yosemite falls at night, (courtesy of Dr Karl and Radio 5's 'Up all Night' programme). A moonbow is a rainbow at night. Light from the full moon, shining upon water vapour in the air, can produce a rainbow via the same mechanism by which light from the Sun produces a daytime rainbow. The full Moon is required to produce sufficient light to excite the colour receptors in the eye.