EUROPE:An Earth-like planet that could be covered in oceans and may support life has been discovered outside the solar system.
The new world, which is 20.5 light years away, orbits a region with the right temperature to allow liquid water on its surface.
Scientists believe it is only 1.5 times larger and five times more massive than Earth, making it the smallest extra-solar planet known.
But the really exciting discovery is that the planet lies within the habitable zone of its parent star, Gliese 581.
Also known as the "Goldilocks zone", this is the narrow orbit in which temperatures are not too hot, not too cold, but just right for surface water to exist as a liquid.
The habitable zone varies according to the heat output of the star, and Gliese 581 is much smaller and colder than the sun.
So even though the planet is 14 times closer to the star than the Earth is to the sun, it lies in a region where rivers, lakes and oceans are possible.
Dr Stephane Udry, from the Geneva Observatory in Switzerland, who led the European astronomers who announced the find, said: "We have estimated that the mean temperature of this super-earth lies between zero and 40 degrees Celsius, and water would thus be liquid."
Given its size and location, it is also likely to have an atmosphere.
"On the treasure map of the universe, one would be tempted to mark this planet with an X," said Dr Xavier Delfosse, a member of the team from Grenoble University in France.