What’s at the moonbow’s end?

NASA posted this wonderful photo the other day. It is one more reason why I should save up for a trip to Iceland.


Waterfall, Moonbow, and Aurora from Iceland
Image Credit and Copyright: Stephane Vetter (Nuits sacrees)

The longer you look at this image, the more you see. Perhaps your eye is first drawn to the picturesque waterfall called Skogarfoss visible on the image right. Just as prevalent, however, in this Icelandic visual extravaganza, is the colorful arc of light on the left. This chromatic bow is not a rainbow, since the water drops did not originate in rainfall nor are they reflecting light from the Sun. Rather, the drops have drifted off from the waterfall and are now illuminated by the nearly full Moon. High above are the faint green streaks of aurora. The scene, captured one night last month, also shows a beautiful starscape far in the background, including the Big Dipper, part of the constellation of the Great Bear (Ursa Major).

It’s so beautiful and otherworldly. When I showed the image to a co-worker, he wondered how come there were both a rainbow and stars in the photo. Except that what looks like a rainbow was made by the light of the moon. How dreamy.