astroengine writes "Gliese 667C is a well-studied star lying only 22 light-years from Earth in the constellation of Scorpius, but it appears to have been hiding a pretty significant secret. The star has at least six exoplanets in orbit, three of which orbit within the star's "habitable zone" — the region surrounding a star that's not too hot and not too cold for liquid water to exist on their surfaces. Astronomers already knew that Gliese 667C had three worlds in orbit, one in the star's habitable zone, but the finding of three more exoplanets, two of which are also in the habitable zone is a huge discovery. Finding one small planet in a star's habitable zone is exciting, but finding three is historic. 'The number of potentially habitable planets in our galaxy is much greater if we can expect to find several of them around each low-mass star — instead of looking at ten stars to look for a single potentially habitable planet, we now know we can look at just one star and find several of them,' said Rory Barnes, of the University of Washington, co-author of the study, in an ESO press release Tuesday (June 25)."