Resumen de Touch down on a comet...
Clark talks about comet exploration. In 2013, comet ISON flew into human skies. In 2014, they will return the favor when the European Space Agency's Rosetta craft begins orbiting comet Churyumov-Gerasimenko and touches down on its surface. That would mean two firsts for comet exploration--plus the most ambitious deep-space landing ever attempted. Rosetta is a veteran traveller. Launched in March 2004, it has spent a decade looping around the sun, gaining momentum--and passing two asteroids. Its target travels at about 16 kilometres per second, and Rosetta is now catching the comet by 800 metres each second
