ISBN: | 978-5-5105-2912-8 |
High Quality Content by WIKIPEDIA articles! An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of 760 such planets have been identified as of February 14, 2012. It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars. It follows that tens of billions of exoplanets must exist in the Milky Way Galaxy alone.