Rosetta: mission to land on a comet

In 2014, the European Space Agency's Rosetta probe will enter orbit around a comet -- the first time this will have ever been done -- and then drop a lander on it -- and oh yeah, that's the first time this will have ever been done, too. I'm pretty excited about this mission, and NASA and ESA have put together this really well-done video explaining the mission and what it'll do: