From VOA News:
After a decade-long six-billion-kilometer chase, its Rosetta orbiter made history Wednesday, finally catching up with Comet 67P halfway between the orbits of Jupiter and Mars.
The ESA's $1.7 billion probe is the first spacecraft to rendezvous with a comet.
After entering orbit 100 kilometers above the surface of the 67P/Churymov-Gerasimenko comet early Wednesday morning, at a distance of more than 400 million kilometers from Earth, images soon emerged that showed the vessel heading toward a massive rock spinning in the starry dark.
Rosetta will escort Comet 67P for the next year and observe it as it heads towards the sun. The highlight of the mission will come in November, when Rosetta will release a small probe that will attempt to land on Comet 67P — the first ever spacecraft to accomplish such a feat.The ESA website has more information on the rendezvous, including a nice photograph of the comet.