Rendez-Vous with Mercury

As the MESSENGER spacecraft approached Mercury for its first flyby, the Narrow Angle Camera, part of the Mercury Dual Imaging System (MDIS) instrument, acquired a series of images of the Planet in support of spacecraft navigation.
The 9 images shown here were taken from January 9 to 13, 2008, as MESSENGER closed to between 2,7 MKM and 760.000 Km (1,7 MMs and 470.000 miles) from Mercury. (...)

At the beginning of the image sequence, Mercury was no more than a bright crescent in the blackness of space. As MESSENGER drew closer, surface features began to be resolved. The image from January 13 (bottom right) has the highest spatial resolution of this sequence (20 Km/pixel, such as about 12 miles/pixel).
In this image, bright markings are visible, and impact craters can be seen near the Terminator.