The Sky at Night goes behind the scenes at the European Space Agency as the Rosetta mission reaches its conclusion and the spacecraft is crashed into the surface of comet 67P Churyumov-Gerasimenko. For nearly two years the Rosetta spacecraft has been in orbit, studying the comet at close range and returning extraordinary pictures. But now the the mission must end and the project scientists have decided to have one final attempt at studying it at close range. On September 30th the spacecraft - with all its instruments running - will be crashed into the surface of the comet. Its aim is to get the best ever view of the mysterious pits on the comet's surface, pits whose walls are thought to have been undisturbed for over 4 billion years. Chris Lintott will be in mission control with the scientists as they watch the pictures come in from the spacecraft's dive towards the surface. Maggie Aderin-Pocock will be investigating how the mission has transformed our understanding of comets.