Cover image: Pictured are representations of the orbits and relative physical sizes of 1,475 extrasolar planet candidates discovered by NASA's Kepler mission since 2009, including an excerpt of the 589 systems with two or more transiting planet candidates. More than half of the planet candidates shown have been statistically confirmed as true planets. The Exoplanets Special Feature, appearing in this issue, presents recent findings regarding the diversity of exoplanet sizes, compositions, and orbital distances, as well as the conditions likely to support life on exoplanets and potential methods for remotely detecting evidence of biological activity. See the Introduction to the Special Feature by Adam S. Burrows and Geoffrey W. Marcy on pages 12599–12600. Image courtesy of Daniel Fabrycky (University of Chicago, Chicago).