Life could exist on billions of planets
Billions of potentially habitable planets may exist in our own galaxy, the Milky Way.
Around 100 "super-Earths" may be found on our galactic doorstep, less than 30 light years from the sun.
Astronomers came up with the prediction after conducting a survey of red dwarf stars, which make up 80pc of stars in the Milky Way.
They calculate that around 40pc of red dwarfs have a rocky planet not much bigger than Earth orbiting a "habitable zone" where liquid surface water can exist. Where there is water, there could be life.
Dr Xavier Bonfils, from Grenoble University in France, who led the international team, said: "Because red dwarfs are so common -- there are about 160 billion of them in the Milky Way -- this leads us to the astonishing result that there are tens of billions of these planets in our galaxy alone."
The research is reported in the journal Astronomy & Astrophysics.