On the Cover: On June 5 and 6, 2012, people all over the world watched as Venus passed in front of the Sun, but the best views were from spacecraft. This image is composed of fifteen photos of the event, taken through an extreme ultraviolet filter by NASA’s Solar Dynamics Observatory. Venus is silhouetted against the solar corona, where ionized plasma reaches a temperature of a million degrees, radiating brightly in extreme ultraviolet light. The image has been rotated so that the Sun’s north pole is at left. NASA/GSFC/SDO
6 The Bradbury Imperative:Andrew Chaikin reflects on why we must explore.
8 Where We Stand: Politics and budgets and waiting, with Casey Dreier.
9 COVER STORY The Year in Pictures:Emily Lakdawalla shares her favorite images from the past year.