Has there ever been a report of a moon rainbow?
This may be a silly question, but has there ever been a report of a moon rainbow?
— Shawn Benham, Valparaiso, Ind.
It is not a silly question, as moonbows, or lunar rainbows, do occur. They form in the same manner as a rainbow, except the light source is the moon rather than the sun, with moonlight reflected and refracted through raindrops to form a pale-colored bow. Since moonlight is much dimmer than sunlight, the moonbow’s colors are faint and muted in comparison with a typical rainbow, often appearing in varying shades of gray and white.
Moonbows are observed much more frequently in the tropics, where the co-existence of nocturnal showers and moonlight is much more common than at higher latitudes, where night skies tend to be overcast when it is raining.