THE striking success of a new planet-hunting technique that has found a chilly “super-Earth” nearly 9000 light years away is not only suggesting that such planets are common, it is even encouraging astronomers to look for planets beyond our own galaxy.
Around 170 extrasolar planets have been discovered so far, most of them gas giants like Jupiter circling nearby stars. The majority have come to light because their immense gravity makes their parent stars wobble, a motion that has revealed planets up to a few hundred light years away.
Last year, observations of a phenomenon called microlensing found a planet…
