How clean is really clean? This month, as Europe's Rosalind Franklin Mars rover leaves the UK, Space Boffins visit the clean room to discover the effort needed to keep Mars safe from Earth-bugs. With guest NASA Curiosity mission scientist Sanjeev Gupta from Imperial College London, we hear about the two Mars rovers heading to the red planet in 2020 and their search for past or present life. We also go inside the Airstream trailer in California where Apollo astronauts lived after returning from the Moon and there's (yet another) new jingle - can you identify where the clips come from? Like this podcast? Please help us by supporting the Naked Scientists