From Citizendium - Reading time: 1 min
Philae is a European Space Agency device[1] which landed on the nucleus of a comet on 12th November 2014, the first time in history that this had been achieved. Philae initially bounced off the surface, ultimately coming to rest in a position that did not allow enough sunlight to reach its solar panels, so ceased sending back data after three days, when its batteries ran out.[2] Its harpoons and screws also failed to anchor it to the surface, which was much harder than expected.[3]
As part of a wider mission to investigate comet activity, Philae was launched on 2nd March 2004 with the Rosetta spacecraft, which took up a position in orbit of comet 67P/Churyumov–Gerasimenko prior to releasing the lander.