The Italian priest Giordano Bruno was burned at the stake in 1600 for, among other things, imagining an infinite number of other worlds and claiming that “innumerable suns exist; innumerable earths revolve about these suns.”
Modern astronomers are proving Bruno right – there really are innumerable suns with innumerable planets revolving around them.
An extrasolar planet, or exoplanet, is a planet outside our solar system. As of early September, a total of 836 exoplanets have been found. Astronomers now believe that more than half of all sunlike stars harbor at least one planet, leading to the estimate of at least 160 billion exoplanets in our own Milky Way galaxy.
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of 839 such planets (in 662 planetary systems, including 125 multiple planetary systems) have been identified as of October 5, 2012. Estimates of the frequency of systems strongly suggest that more than 50% of Sun-like stars harbor at least one planet. In a 2012 study, each star of the 100 billion or so in our Milky Way galaxy is estimated to host “on average … at least 1.6 planets.” Accordingly, at least 160 billion star-bound planets may exist in the Milky Way Galaxy alone. Unbound free-floating planetary-mass bodies in the Milky Way may number in the trillions, with 100,000 objects larger than Pluto for every main-sequence star.