"We have estimated that the mean temperature of this 'super-Earth' lies between 0 and 40 degrees Celsius, and water would thus be liquid," explained Stephane Udry of the Geneva Observatory "Moreover, its radius should be only 1.5 times the Earth's radius, and models predict that the planet should be either rocky - like our Earth - or covered with oceans."
Gliese 581c is the smallest exoplanet found so far, and completes a full orbit of its parent star in just 13 days. It is 14 times closer to its star than the Earth is to our Sun. However, Giese 581 is smaller and colder than the Sun - and thus less luminous - the planet lies in the star’s "habitable zone". The “super earth” is one of three exoplanete discovered in the Gliese 581 system.
Commenting on the discovery, Alison Boyle, the curator of astronomy at London's Science Museum, said: "Of all the planets we've found around other stars, this is the one that looks as though it might have the right ingredients for life.”