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.

The Sky at Night team looks back on the major stories of the year and sees how they have developed since they hit the headlines. 2016 has been a remarkable year in many ways, but one area in which it has been particularly good is in space science. There have been new missions to Jupiter and Mars, planets have been found on the outskirts of the solar system and around our nearest neighbouring star, and the discovery of gravitational waves has potentially given us a new way of investigating the universe. What has the Juno probe discovered at Jupiter? Has Planet 9 been found? And are we any closer to finding Earth-like planets elsewhere in the galaxy?