MOONBOWS

 

Arne-kaiser, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons

Moonbows are the same as rainbows except that the moon, instead of the sun, is the source of light.  They are very rare due the fact that all conditions have to be exactly right in order for them to be visible.  The only two places on earth where there is any reasonable chance of finding one on a regular basis are at Cumberland Falls near Corbin, Kentucky or at Victoria Falls in Zambia.

Due to the low level of illumination, the human eye usually perceives the moonbow as pure white.  However, if a time-lapse photo or a photo with high-speed film is taken, the full colors of a normal rainbow will be visible in the picture.