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.

3 comments:

Brooke said...

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

FJ 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!

tmw