The Messenger spacecraft launched in 2004, and entered orbit in 2011. Messenger mapped the entire surface of Mercury at high detail giving us awesome pictures such as this:
The detail in this image is simply amazing!
In addition to studying Mercury, Messenger has also studied energy flows from the Sun. Alas, all good things must come to an end and that holds true for Messenger. The official end of the mission occurs very soon with a controlled descent and crash into the surface of Mercury. Will another 30-40 year elapse before we visit Mercury again? Only time will tell. For more information on the Messenger mission, check out: