Unless Matt Damon becomes stranded on Comet 67P/Churyumov–Gerasimenko any time soon and needs an emergency means of calling back to Earth, the world will never hear from the Rosetta spacecraft again. But the European vehicle served humanity well since its launch 12 years ago. Rosetta became the first probe to both orbit a comet and deploy a lander to a comet's surface. On Friday morning, the spacecraft joined its small lander, Philae, on the surface of its comet. Once there, it shut down.
Even before the European Space Agency’s Giotto spacecraft came within 600km of the nucleus of Halley’s Comet in 1986, the agency was already thinking about a comet lander as a follow-up mission. After finally launching in 2004, Rosetta took a long time to reach Comet 67P/Churyumov–Gerasimenko. The probe had to make four flybys of inner solar system planets (three around Earth, one around Mars) for gravitational assists, and it traveled nearly eight billion km before descending to rest on the comet Friday. The gallery above captures some of the highlights of the 12-year mission.
From a scientific standpoint, Rosetta confirms that comets are remnants from when the Solar System formed, rather than fragments from later collisions. Comets therefore offer a window to 4.6 billion years ago. The program was a public relations success, too. “As well as being a scientific and technical triumph, the amazing journey of Rosetta and its lander Philae also captured the world’s imagination, engaging new audiences far beyond the science community,” said Mark McCaughrean, ESA’s senior science adviser.