Red Sky at Night
July 24, 2001
A hot summer day in the midwest ends in a brilliant sunset, and did not disappoint followers of the saying "red sky at night, sailor's delight" - the following day was sunny and hot. Water and dust in the atmosphere scatter more and more of the shorter wavelength blue and green light as the path length of the light from the sun to the observer through the atmosphere increases at sunset. The red light is not scattered as strongly and shines through to illuminate the bottoms of nearby clouds, enhancing the brilliance of the day's final moments.