Seen just a handful of times this stunning phenomenon is known as the 'smile in the sky. Freak weather conditions created this reverse rainbow in Leicestershire where it was pictured by antique dealer William Freeman. But while the sight looks like an upside-down rainbow, it is actually caused by light shining through tiny ice crystals in the clouds. Rather than being caused by raindrops like normal rainbows, it is the result of freak atmospheric conditions, rarely seen outside the North and South Poles. This is one of only a handful of occasions where an arc has been spotted in the UK. DM