Rosetta is a robotic spacecraft built by the European Space Agency which is due to reach comet 67P/Churyumov–Gerasimenko in August. It’s the first mission designed to both orbit and land on a comet.
The Rosetta space probe orbiter, which features 12 instruments, will orbit 67P for 17 months and is designed to complete the most detailed study of a comet ever attempted. In November 2014 the Philae robotic lander, with an additional nine instruments, will approach Churyumov–Gerasimenko slowly, then fire two harpoons into the comet to prevent the lander from bouncing off. Both the orbiter and lander will stay with the comet as it goes around the sun.
You can’t land on a comet core without knowing its shape, so Rosetta has been observing the comet core as it approaches. It’s a weird shape, even for a comet. Some people thought that it might be a binary – two comet cores rotating each other, and touching. Actually, it’s more like a rubber duck.
This is going to be fun.
