Rocky planets, possibly with conditions suitable for life, may be more common than previously thought in our galaxy, a study has found.
New evidence suggests more than half the Sun-like stars in the Milky Way could have similar planetary systems.
There may also be hundreds of undiscovered worlds in outer parts of our Solar System, astronomers believe.
Future studies of such worlds will radically alter our understanding of how planets are formed, they say.
New findings about planets were presented at the American Association for the Advancement of Science (AAAS) in Boston.
BBC NEWS | Science/Nature | Planet-hunters set for big bounty