Rare Safari Sighting: A Lunar Rainbow at Victoria Falls
The most remarkable thing you see on an African safari could be up in the night sky! Learn where and when to spot a lunar rainbow at Victoria Falls — one of the few places in the world to see them.
Also known as moonbows, these ethereal rainbows of the night are caused by the refraction of moonlight through water droplets. Lunar rainbows are much fainter than daytime rainbows due to the lower level of light reflected by the moon. In addition to a full moon, they also require a dark, cloud-free sky, and the proper viewing position relative to the moon.
There are few places on earth that meet all these conditions. In the United States, lunar rainbows may be seen at Yosemite National Park in California and Cumberland Falls in Kentucky, but no longer at Niagara Falls due to the interference of light pollution. Luckily this natural phenomenon occurs regularly at the Victoria Falls, and evening tours make viewing the spectacle very easy when spray and cloud cover permit.
The lunar rainbow at Victoria Falls is best seen at times of high water (April to August) when there is sufficient spray to create the moonbow effect. This spectacle is best witnessed in the early hours after moonrise, before the moon rises too high to create a moonbow that is visible to the ground-based observer. Lunar rainbows are generally accepted to be best viewed from the Eastern Cataract on the Zambian side, where the moon rises behind the observer, creating a lunar rainbow over the aptly named ‘Rainbow Falls’. The moonbow can also be viewed from the bridge.
How much color you see in the moonbow depends also on the quality of your night vision and the number and responsiveness of color sensitive cones present in your retinas. Some people are able to see the subtle colors, and others only see faint shades of white. However, the colors of a lunar rainbow do show in photographs with a long exposure.
Tours can be arranged the night before, night of and night after the full moon, when the moon is at its brightest and the chances of seeing a moonbow are greatest. Review the full moon dates below, and if your travel plans have you in the vicinity of Victoria Falls during one of these dates, ask your Bushtracks safari planning expert to schedule a tour to spot a lunar rainbow at Victoria Falls.