Countdown to Rosetta’s comet landing

The Rosetta space mission will attempt the first ever landing on the surface of a comet on 12^th November 2014. This mission will be the key to furthering our understanding of the formation of our solar system and the origins of life. The European Space Agency (ESA) will aim to land the Philae landing craft on the smaller of two ‘lobes’ of comet 67P/Churyumov-Gerasimenko at a site which has recently been named ‘Agilkia’ after an island on the river Nile. “Now that we know where we are definitely aiming for, we are an important step closer to carrying out this exciting – but high-risk – operation,” said Fred Jansen, ESA’s Rosetta mission manager. Comets are considered to be primitive building blocks of the solar system and may have helped to ‘seed’ Earth with water and perhaps even the organic molecules required for life. On board the Philae lander is the UK-led Ptolemy instrument which will perform on-the-spot analysis of the composition of the ice and organic material within the comet. Philae will be released at 08:35 GMT on 12^th November at a distance of approximately 22.5 km from the centre of the comet. Landing will be about seven hours later at around 15:30 GMT. During its descent, Philae will take images and conduct experiments, sampling the dust, gas and plasma environment close to the comet. Once safely on the surface, Philae will take a panorama of its surroundings. These images will take several hours to reach Earth. The first sequence of surface science experiments will begin about an hour after touchdown and will last for 64 hours, constrained by the lander’s primary battery time. http://youtu.be/szKZ77MbF9Q However, before Philae is released, a number of decisions must be made to assess the situation: “If any of the decisions result in a No-Go, then we will have to abort and revise the timeline accordingly for another attempt, making sure that Rosetta is in a safe position to try again,” said Jansen. Rosetta has already been orbiting 67P since August 2014, mapping the comet’s surface; making important measurements of its gravity, mass and shape; assessing its gaseous, dust-laden atmosphere; and probing its plasma environment. “As things stand, the orbiter will continue to shadow the comet until the end of next year. This will be an opportunity to observe how the body responds to its close passage to the sun,” said Professor Ian Wright, principal investigator for the Ptolemy instrument. By Rebecca Dey