The European Space Agency’s Rosetta spacecraft swept past the Earth and Moon on Friday, gaining a gravity speed boost on its 10-year journey to reach Comet 67P/Churyumov-Gerasimenko. At its closest point, Rosetta passed just 1954 km (1214 miles) above the Pacific Ocean before speeding back off into space. This flyby allowed controllers to rehearse their procedures on a “fake asteroid” (the Moon), as Rosetta will visit two asteroids as part of its mission. Rosetta will make two more visits to Earth and one to Mars before its trip is complete.