Mercury: Images of a Violent Planet

On Oct. 6, 2008, at 4:40 a.m. ET, the Messenger spacecraft passed a mere 124 miles above Mercury's surface for its closest approach to the planet during the mission's second Mercury flyby. The planned flyby observations continue for about 20 hours following the closest approach, and only after the completion of all scientific observations will the data be transmitted to Earth. (NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)