Lander to aim for comet's 'head'

摘要

There is no easy way to alight on a 4-kilometre-long, rubber-duck-shaped ice ball that is spinning as it flies through the outer Solar System. But scientists working on the European Space Agency's Rosetta mission have selected a spot on the 'head' of the comet, called 67P/Churyumov-Gerasimenko, that they think will give them the best chance for gently landing Philae, a washing-machine-sized robotic probe. Planned for 11 November, the first soft landing ever attempted on a comet is fraught with risk. When researchers still thought that the object had a regular, potato-like shape, they estimated the landings chance of success at 70-75%. Now that the Rosetta orbiter has taken a closer look and revealed the curious shape, the odds are lower. Mark McCaughrean, a senior science adviser at the European Space Agency (ESA) directorate of science and robotic exploration in Noordwijk, the Netherlands, puts them at roughly "fifty-fifty".