Ian Sample in The Guardian:
The European Space Agency's Rosetta probe aims for a spectacular first in space exploration. The billion-euro machine will catch up with a comet, circle it slowly, and throw down a lander to the surface. With gravity too weak to keep it there, the box of electronics and sensors on legs will cling to its ride with an explosive metal harpoon.
Together, the Rosetta probe and its lander, Philae, will scan and poke the comet as it tears towards the sun. As the comet draws near, it will warm and spew huge plumes of gas and dust in a tail more than one million kilometres long. The spectacle has never been captured up close before.
The comet, named 67P/Churyumov-Gerasimenko, formed from cosmic debris 4.6bn years ago, before material had coalesced to form the Earth and our nearest planets, and the sun was a newborn star. Even rocket scientists find the comet's name hard work. Some opt instead for “Chury”.
By studying the comet – some of the most pristine and primordial material there is – scientists hope to learn more about the origins of the solar system. The presence of ice, and traces of organics, might hint at answers to other big questions: how Earth got its water and how life began. But first the spacecraft must wake up.
More here.