Here's the fifth of those optical navigation shots that MESSENGER's taking as it approaches Mercury (click to enlarge to see the details):
NASA / JHUAPL / CIW
MESSENGER approaches Mercury
This is the fifth of MESSENGER's optical navigation images of Mercury during its approach to its second flyby, taken on October 5, 2008, from a distance of 690,000 kilometers.
NASA / JHUAPL / CIW / Eric Landrenau
MESSENGER departs Mercury
This approximately true color view of Mercury was created by manipulation of the color space of the false-color official release from the MESSENGER team. The image was captured as MESSENGER departed its first flyby of Mercury on January 14, 2008. Caloris is a large bright basin in the top half of the image. Tolstoj is a dark-ringed impact structure, highly foreshortened at about 4:00 on the limb.