In April 2021, a photograph was widely circulated on social media that supposedly showed a double rainbow arching over the U.S. Capitol. While many viewers were impressed with the natural symmetry of the photo (the rainbows appear to perfectly frame the building), others claimed that this image was obviously digitally manipulated:
This is a genuine photograph that was taken by Carissa Bunge, a senior legislative assistant at the U.S. House of Representatives.
While some viewers were skeptical of this image, there truly was a double rainbow over Washington, D.C., on the evening of April 11, 2021. Another amateur photographer, Instagram user Kendy Garden, posted a very similar image to their Instagram page:
The Capitol Weather Gang, The Washington Post's D.C.-based weather account on Twitter, collected several other images of these rainbows around the capitol.
Meteorologist Matthew Cappucci wrote in The Washington Post that the above-displayed rainbow was a supernumerary bow, which means that it had faint, secondary arches of color inside the inner rim of the primary rainbow. Cappucci writes:
Observers in and around D.C. noticed some additional colors inside the primary arc during Sunday’s show, too — with up to three repeating bands of colors packing the inner rim of the rainbow. Sunday’s rainbow was a “supernumerary” bow, and formed thanks to a high number of smaller raindrops present in the atmosphere.
When two beams of sunlight enter a raindrop, even though they’re parallel when they enter, they strike the back edge of the raindrop in slightly different places, and subsequently are bounced in acutely different directions when they exit. For an individual color, which is composed of a wavelength of alternating crests and troughs, that means the two light beams may no longer overlap “in phase.”
While these photos may be pretty stunning, rainbows over the Capitol aren't a very unusual sight. In the last year, rainbows in D.C. have made the news at least twice as they seemingly made symbolic appearances. For example, a rainbow was spotted as late civil rights leader John Lewis lying in state, and another rainbow was spotted on Election Day in November 2020.