Water vapour has been detected in the atmosphere of a planet orbiting a star 64 light-years away from the Earth. The international research team responsible for the discovery says it is an important step towards the detection of life on an extra-solar planet.

The scientists used Nasa’s Spitzer space telescope to identify the chemical signature of water in the atmosphere of a planet known as HD 189733b, in the constellation of Vulpecula, the little fox.