Brian Cox and Robin Ince are joined by comedian Jo Brand, planetary scientist Professor Monica Grady and NASA scientist Dr Carolyn Porco as they discuss some of the most exciting and technically ambitious explorations of our solar system. They'll be looking at the Rosetta mission that has, for the first time, landed a probe on a comet, and the Cassini-Huygens mission which is bringing us extraordinary information about Saturn and its moons, and what these explorations of the far reaches of our solar system might tell us about our own planet.