Social media exploded with photos of what looked like a rainbow that appeared right over the pope’s location in New York City on Friday. It was a beautiful sight, but it wasn’t a rainbow.

Thanks to Sue of Campbellsburg, IN for sending in this pic. The one at the top of this post is the close up of the circumzenithal arc and the one below is the whole picture. The sun was at the bottom.

It's called a circumzenithal arc and is caused by the refraction of sunlight through ice crystals in the upper atmosphere. It's similar to a halo around the sun or moon. To see a circumzenithal ...

"When it comes to atmospheric optics, one of the most captivating and awe-inspiring phenomena is the circumzenithal arc," reads the Atmospheric Optics website. "Imagine a rainbow that has escaped ...

An upside down "rainbow" has been spotted in the sky above Essex. Rachel Sanders spotted the circumzenithal arc in Gosfield, near Halstead, on Monday. The Met Office said the phenomenon was a type ...