National Geographic has some cool shots coming down from NASA’s MESSENGER
SATELLITE satellite. Why has it taken NASA so long to place the probe, which was launched in August of 2004, on Mercury? Wired explains:
Placing a satellite into orbit around Mercury is particularly challenging because of the energy the spacecraft picks up from the gravitational attraction of the sun. Since Mercury’s atmosphere is too sparse for aerobraking, a complex series of maneuvers involving Earth, Venus, and Mercury was required to slow the craft down sufficiently. This multi-flyby added many years and almost 5 billion miles to the trip for the probe.
As usual, Space.com also has a pretty good write-up.