> Using these data, scientists will choose a landing site for the mission’s 100 kg Philae probe. The landing is currently scheduled for 11 November and will be the first time that a landing on a comet has ever been attempted. In fact, given the almost negligible gravity of the comet’s 4 km-wide nucleus, Philae will have to use ice screws and harpoons to stop it from rebounding back into space after touchdown.