A terrestrial planet in a ~1-AU orbit around one member of a ∼15-AU binary

Many known exoplanets (planets outside our own solar system) are hosted by binary systems that contain two stars. These planets normally circle around both of their stars. Using microlensing data taken with a worldwide network of telescopes, Gould et al. found a planet twice the mass of Earth that circles just one of a pair of stars. The same approach has the potential to uncover other similar star systems and help to illuminate some of the mysteries of planet formation. Science , this issue p. [46][1] [1]: /lookup/doi/10.1126/science.1251527