The MESSENGER spacecraft has just made its third flyby of Mercury, passing over just 228 kilometers away from the surface. It takes a lot of energy to directly get from Earth orbit to Mercury orbit, so MESSENGER has been making multiple flybys of Mercury. During each flyby, the planet is used as a gravity assist so that the spacecraft can achieve Mercury orbit with much less fuel. This is the final flyby of Mercury, and MESSENGER will start orbiting Mercury and studying the planet in March, 2011.
Now that MESSENGER has made its third flyby, we just need to wait for the spacecraft to send the data and have it processed for more cool images of Mercury …