Alexia Major (Member 61,450) observed this crooked, multicoloured smile in the sky a few months before joining the Cloud Appreciation Society. At the time, she thought she was seeing ‘an incomplete rainbow’. After joining the Society, she had learned about the optical effects clouds can produce and correctly identified it as a circumzenithal arc. 

Alexia’s smile was formed in a vertical strip of Cirrus clouds which were likely the remnants of an aircraft contrail. The ice crystals forming in the high cloud were likely in the shape of tiny hexagonal plates. When ice crystals like these fall horizontally through the sky, like autumn leaves, they can refract the sunlight shining through them to form the circumzenithal arc of colours way up in the sky directly above. 

‘My son and I were playing outside on a spring day,’ Alexia said, ‘and I just happened to look up – and what magic was above me!’