Extrasolar planet. 2 January 2013: Astronomers state that the Milky Way may contain as many as 400 billion exoplanets, with almost every star hosting at least one planet.[1][2][3] An exoplanet or extrasolar planet is a planet outside the Solar System. Around 1800 such planets have been discovered[5][6][7] (1783 planets in 1105 planetary systems including 460 multiple planetary systems as of 18 April 2014).[8] The nearest known exoplanet, if confirmed, would be Alpha Centauri Bb, but there is some doubt about its existence. Almost all of the planets detected so far are within the Milky Way; however, there have been a small number of possible detections of extragalactic planets. For centuries philosophers and scientists supposed that extrasolar planets existed, but there was no way of detecting them or of knowing their frequency or how similar they might be to the planets of the Solar System. History of detection[edit] Early speculations[edit] Discredited claims[edit] In 1991 Andrew Lyne, M.
Transit method. Extrasolar Visions - An Extrasolar Planets Guide. Extrasolar-planets.com. Exoplanet Orbit Database | Exoplanet Data Explorer. Extrasolar Planet News.