The sky smiled on Cambridge, England, on Sept. 14 — in the form of what some are calling an upside-down rainbow.
Jacqueline Mitton, an astronomer who captured the phenomenon on camera, said it was caused by ice crystals high in the atmosphere that reflected light back up into the sky, The (London) Daily Telegraph reported.
Mitton, 60, said she’s never seen anything like it before.
I spotted a photo at the Web site Zeitgeist.
After looking at the photo, Brad Ketcham of the National Weather Service in Wichita told me the phenomenon is not a rainbow but an atmospheric “halo” or a “sun dog” – a circular reflection of ice crystals.
“It’s just a more vibrant one. Usually, sun dogs or halos are not that bright.”
A rainbow is caused by light reflecting off of raindrops, while sun dogs are caused by light reflecting off ice crystals, Ketcham said. Nonetheless, “I can see why people are calling it a rainbow.”
For a reference point, here is a photograph of a halo taken at Table Mountain in California by a NASA employee in 1990.