We all know rainbows and the same principle applies to a moonbow, but it is rarely seen as it requires quite a combination of conditions. But there are several places in the world where moonbows are produced by spray of a waterfall and the Victoria Falls in Zambia/Zimbabwe are one of those places where you can see a moonbow. Only make sure you plan your African safari holiday between January and July as it needs high water levels to produce sufficient spray for the moonbow to appear.
Wikipedia: “A moonbow (also known as a lunar rainbow, black rainbow, white rainbow, lunar bow, or space rainbow) is a rainbow produced by light reflected off the surface of the moon (rather than from direct sunlight) refracting off of moisture in the air. Moonbows are relatively faint, due to the smaller amount of light reflected from the surface of the moon. They are always in the opposite part of the sky from the moon. Because the light is usually too faint to excite the cone color receptors in human eyes, it is difficult for the human eye to discern colors in a moonbow. As a result, they often appear to be white. However, the colors in a moonbow do appear in long exposure photographs. Few places in the world frequently feature spray moonbows. Such sites in the United States include several waterfalls in Yosemite National Park, California and Cumberland Falls, near Corbin, Kentucky. Victoria Falls, in Africa on the border between Zambia and Zimbabwe, is also widely known for spray moonbows.”
It is definitely a fantastic event for a photographic safari and challenging to get the picture right. It is one of the great sights and activities the Victoria Falls have to offer, a must see place when visiting Southern Africa.