One of the European Space Agency’s flagship missions reached its grand finale on Friday 30 September 2016. After 20 years in development, a 10-year trip around the Solar System and two years on station at Comet 67P/Churyumov-Gerasimenko, the Rosetta mission drew to a close at 12:19 BST when the spacecraft performed an intentional crash-landing on the comet’s surface.
This marked the end of a fantastically successful science campaign aimed at unraveling the mysteries of comets. These objects, which create spectacular apparitions on the night sky as they approach the Sun and grow tails, are thought to represent pristine material left over from the Solar System’s formation. By rendezvousing with one such object and following it through its passage near the Sun, Rosetta told us that’s it’s made of a mixture of ice, rock and dust, including complex organic compounds; how its ices turn into the gas feeding the tail we see at the telescope; and dropped a lander called Philae that became the first human artefact to ever land on a comet. Now, as 67P is receding from the sun there is not enough sunlight and heat to keep Rosetta operating, hence the decision to end the mission. However, the flow of scientific discoveries is not expected to dry up anytime soon. Scientists have barely began to pore over the treasure trove of data beamed back from it and the intrepid Philae over the two years it spend at comet 67P. The adventure of seeking out cometary secrets has only just began.
(Article by Apostolos Christou, Research Astronomer, Armagh Observatory and Planetarium)