An anonymous reader writes A newly discovered planet in a binary, or twin, star system located 3,000 light-years from Earth is expanding astronomers' notions of where Earth-like planets can form. At twice the mass of Earth, the planet orbits one of the stars in the binary system at almost exactly the same distance at which Earth orbits the sun. However, because the planet's host star is much dimmer than the sun, the planet is much colder than Earth. "This greatly expands the potential locations to discover habitable planets in the future," said Scott Gaudi, professor of astronomy at Ohio State. "Half the stars in the galaxy are in binary systems. We had no idea if Earth-like planets in Earth-like orbits could even form in these systems."