A rare rainbow cloud appeared to light up the sky over part of south east England this weekend. Surrey resident, Mark Stay, tweeted this picture from the grounds of a National Trust property.
Beautiful rainbow clouds over Polesden Lacey earlier. http://t.co/vjqMWWsZqa
Officially these clouds are known as iridescent clouds, where very small water droplets or ice crystals scatter light individually. The effect is similar to the colours often seen when oil lies on the surface of water.