Mysterious double rainbow

Rainbows are studied for hundreds of years, since the XVII century, when Isaac Newton first explained this colorful heavenly phenomenon. But there is one version of it, which is still not completely understood by scientists, is a double rainbow. Jan Curtis captured a rare specimen on June 21 from the American city of Cheyenne in the state of Wyoming.

“This rare double rainbow was perhaps the brightest rainbow I’ve ever seen. It appeared against a background of a strong thunderstorm, which, fortunately, passed a few miles from my area, “said Curtis.

“Over the years, several double rainbows were recorded, mainly during heavy downpours, but to date there is no agreed explanation for them. Perhaps, they are formed from a mixture of water droplets and ice balls, “says Le Cowley, an expert in atmospheric optics. Indeed, Curtis mentioned the city during his observations.

“It is more likely that one or both arcs produce nonspherical raindrops. Surface tension forces keep small droplets spherical, but as they fall large drops become flattened due to air resistance or even can oscillate between oblate and elongated spheroids, “adds Crowley.

The rainbow in the picture of Curtis is remarkable in that it has a common double structure, in which the inner rainbow is divided into two more.