Science Natural Science Behold the Rare 'Ghost Rainbow' By Bryan Nelson Bryan Nelson Twitter Writer SUNY Oswego University of Houston Bryan Nelson is a science writer and award-winning documentary filmmaker with over a decade of experience covering technology, astronomy, medicine, and more. Learn about our editorial process Updated August 25, 2019 This fogbow, also known as a ghost rainbow, was photographed in New Zealand. Francis Vallance (Heritage Warrior) [CC by 2.0]/flickr Share Twitter Pinterest Email Science Space Natural Science Technology Agriculture Energy Take just one look at this photo and you might find yourself rubbing your eyes before looking again. The colorless, wraith-like rainbow you're seeing is not photoshopped; it's a real phenomenon sometimes called a "ghost rainbow," "white rainbow," or "fogbow." Like with rainbows, fogbows are caused by the refraction of sunlight through water droplets in the air, only with fogbows the droplets are tiny by comparison to raindrops. Droplets in fog are so small (typically smaller than 0.0020 inches) that the colors are far weaker, often with nothing more than a red outer edge and bluish inner edge. Fogbows are so faint that they look like a hollowed out rainbow, the ghost of a once vibrant arc. Hanging over a snowy landscape, however, they appear hauntingly apt. Fogbows are far rarer to witness than rainbows, but they're not entirely unusual either. They are often called by different names depending on the context. For instance, fogbows seen while looking down on clouds from an aircraft are referred to as "cloud bows." Meanwhile, when sailors encounter fogbows through eerie ocean mist, they're often called "sea dogs." Perhaps the most evocative version of all, a lunar fog bow, occurs when light from the moon refracts through a spectral evening haze. To see a fogbow, "wait for a day with bright sunshine at your back, illuminating an area of dissipating or light fog in front of you. This can be in a field, a mountain valley, or at the coast or lakeshore," according to the Weather Channel.