Clouds form to look like an aeroplane soaring across the sky - PHOTO

Is it a bird? Is it a plane? No, it's just a cloud that looks like a plane. As winter slowly makes way for clear blue skies, this cloud bore an uncanny resemblance to an aircraft soaring across the sky.Jet engine vapour trails in the sky are nothing new but one amateur photographer in Devon has captured what appears to be an aeroplane made entirely from cloud.This image of the sky above Dartmouth was captured on camera from a back garden at 8am on Tuesday.It was posted on professional blogger Andy Kyle's website, www.theviewfromthedartmouthoffice.com, which shows unusual and entertaining pics. Vapour trails can create clouds which, experts claim, can block out sunlight for millions.This is the reason that our skies appeared unusually blue when the Icelandic volcano Eyjafjallajokull was erupting in 2010, and all flights over Britain were banned.The phenomenon occurs when aircraft fly above 25,000ft, where the air temperature is around minus 30C. This causes water vapour emitted by the engines to crystallise and form the familiar white streaks across the sky, known as contrails.These can be short-lived. But if there is already a significant amount of moisture in the atmosphere they can linger for hours, as the excess water vapour from the engines tips the surrounding air past its saturation point.This acts as a catalyst to speed up the natural process of cloud formation. Cirrus clouds – the wisp-like formations seen at high altitude – begin to form around the contrails.Scientists say these grow into thin layers of cloud and can cover up to an astonishing 20,000 square miles of sky – or about a fifth of the UK.The level of moisture in the air at high altitudes is unrelated to weather conditions at ground level, which is why it is possible to see contrails on a clear day.Reading University’s Professor Keith Shine, an expert in clouds, said in 2010 that those formed by aircraft fumes could linger ‘for hours’, depriving those areas under busy flight paths, such as London and the Home Counties, of summer sunshine.(dailymail.co.uk)ANN.Az