Wednesday, June 11, 2008

Fire Rainbow

Credit & Copyright: Paul Gitto (Arcturus Observatory)
Explanation: What is that inverted rainbow in the sky? Sometimes known as a fire rainbow for its flame-like appearance, a circumhorizon arc is created by ice, not fire. For a circumhorizon arc to be visible, the Sun must be at least 58 degrees high in a sky where cirrus clouds are present. Furthermore, the numerous, flat, hexagonal ice-crystals that compose the cirrus cloud must be aligned horizontally to properly refract sunlight like a single gigantic prism. Therefore, circumhorizon arcs are quite unusual to see. Pictured above, however, a rare fire rainbow was captured above trees in Whiting, New Jersey, USA in late May.


Brooke said...

Very beautiful. It kind of looks as if the sky is smiling.

Anonymous said...

I've never heard of this before... but it makes sense.

The Merry Widow said...

I saw another, closer shot of a fire rainbow, they are marvelous!