We All Know Rainbows But Have You Ever Seen a Moonbow – A Night Rainbow Lit By the Moon?

A moonbow (also known as a moon rainbow or lunar rainbow) is a rainbow produced by moonlight instead of direct sunlight. Apart from the light source, its formation is no different from that of a solar rainbow: it is created by light being reflected in water droplets in the air caused by rain or a waterfall, for example. They are always positioned on the opposite side of the sky from the Moon relative to the observer.

This set of requirements makes moonbows much rarer than solar rainbows – they actually occur less than 10 percent as often as normal rainbows. Sometimes moonbows can also be observed during full moonrise during the winter months, when the sky is darker and rain falls at extreme latitudes. The definition of the colors is subject to the size of moisture drops present in the air: the smaller they are the less vivid the colors will be. A night rainbow on Fraser Island, Queensland, Australia. Image credit: Garry