Earth’s sister in the crosshairs
Earth’s sister is out there, somewhere, and scientists searching for planets that may support life believe they are closing in on finding just that. “Maybe this year, maybe next — before 2014,” predicted Harvard astronomer Dimitar Sasselov, head of Harvard’s Origins of Life Initiative and co-investigator on the planet-finding Kepler Space Telescope. Sasselov’s prediction may seem bold to those who have not been following the avalanche of new findings in the search for planets circling other stars. From the barest trickle in the mid-1990s, the discovery of extrasolar planets, or exoplanets, has rapidly increased as astronomers have developed new techniques and deployed new instruments, including the 2009 launch of Kepler, specifically designed to find planets around other stars. The telescope already has located more than 2,300 candidate planets, of which 61 have been confirmed as actual planets. Researchers using other telescopes have confirmed hundreds more. The emerging picture is of a universe not...