NASA's MESSENGER mission to the planet Mercury came to a planned, but nonetheless dramatic, end on April 30, 2015 when it slammed into the planet's surface at about 8,750 mph, creating a new crater. MESSENGER was launched on Aug. 3, 2004, and began orbiting Mercury on March 17, 2011. Although it completed its primary science objectives by March 2012, the spacecraft's mission was extended two times, allowing it to capture images and information about the planet in unprecedented detail. Among its many accomplishments, the MESSENGER mission determined Mercury's surface composition, revealed its geological history, discovered that its internal magnetic field is offset from the planet's center, and verified that its polar deposits are dominantly water ice.