Circumzenithal arcs have been described as an “upside down rainbow” or “a grin in the sky.” But circumzenithal arcs are not really rainbows. Instead, they’re caused by ice crystals in the upper atmosphere.
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Thanks for sharing your photo with us Katerina!
Eleanor Imster has helped write and edit EarthSky since 1995. She was an integral part of the award-winning EarthSky radio series almost since it began until it ended in 2013. Today, as Lead Editor at EarthSky.org, she helps present the science and nature stories and photos you enjoy. She also serves as one of the voices of EarthSky on social media platforms including Facebook, Twitter and G+. She and her husband live in Tennessee and have two grown sons.