“Scientists catch a comet and land on its surface” is a headline from the realm of science fiction. Comets are „dirty snowballs“ made up of rock, dust, ice and frozen gases, cruising through the Solar System at high speeds. Little is known about their origins, but scientists suspect they were formed 4.6 billion years ago from the massive spinning cloud of gas and dust that formed our Sun and Solar System. As today’s comets are witnesses of these earliest processes, scientists have been interested in them for a very long time, but until very recently, the idea of flying to a comet and soft-landing on its surface was utterly unthinkable. This changed in 2004 when the European Space Agency launched its spacecraft Rosetta for a 10-year flight to meet 67P/Churyumov–Gerasimenko, a comet of 4 km in diameter, orbiting the sun at speeds of 135,000 km per hour. On 12 November 2014, after travelling a distance of 6.4 billion km, Rosetta’s lander unit Philae successfully touched down on the comet and sent its first data packages to earth. Andrea Accomazzo is the Flight Director of the Rosetta mission, a trained military pilot and experienced spacecraft operations manager. For mastering the highly complex task of guiding Rosetta to its goal, he was listed among Nature’s top 10 scientists of the year 2014. At Falling Walls, he explains how vision, planning, science and engineering took us one step closer to understanding the beginnings of life on Earth.

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