Maggie Aderin-Pocock and Chris Lintott reveal the latest results from Nasa's Curiosity and Esa's ExoMars TGO missions that are attempting to find signs of life on Mars. Maggie visits the Airbus 'Mars Yard' to find out how the next lander heading to Mars is being built to survive the planet's incredibly hostile environment. And the team asks - if Mars is a dead planet, could the first life on Mars be humans? Chris talks to Andy Weir, author of The Martian, about whether a manned mission to Mars is just a fantasy.