Quiara Alegría Hudes (Member 49,909) saw ‘a circular rainbow in the sky’ over New York City, US. In fact, this is a 22-degree halo, an optical phenomenon caused by the refraction of sunlight through the ice crystals in thin cloud like the Cirrus and Cirrostratus formations Quiara spotted here. ‘It looked like the skyscraper was wearing a tiara,’ she said.