Moonbows | The Giordano Bruno Crater | Nicolas Louis de la Caille, his Lunar Crater and the X on the Terminator
Perigee-syzygy Moon, or, 'Supermoon' | Why the Far Side of the Moon Looks Different
A moonbow is an extremely unusual natural phenomenon which only occurs regularly in very specific conditions. Basically they are rainbows that appear at night, as a result of the light of a full, or nearly full, rising or setting moon shining through water droplets in the sky. Moonbows are not to be confused with moon halos, which look like a ghostly halo surrounding the moon.
Moonbows are exceptionally beautiful because they appear as ghostly white bows to our eyes, even though they actually display every colour in the normal rainbow. This lack of colour occurs because of our eyes' lack of colour perception in low light.
Where can I see a Moonbow?
Conditions must be just right for a moonbow to appear. The moon must be full, or near full and there must be water droplets in the sky, but not enough to obscure the moon. In addition, these moonbows can only be seen near moonrise or moonset when the moon is at a low angle in the sky.
Perfect conditions for these moonbows exist in several locations. Notable locations include, Cumberland Falls Kentucky in the United States, the town of Waimea on the big island of Hawaii, and in Kenya. While the moonbows in Kenya and Cumberland Falls regularly occur on the full moon, as the moisture is provided by waterfalls, the moonbows in Waimea are the result of the extremely damp conditions in that town.