The Supermassive team take on their toughest challenge (and most tenuous title) yet…Gravitational Waves. Izzie and Dr Becky explore what they are and ask how the heck to detect something so small? With special thanks to Prof. Mark Hannam from Cardiff University and Prof Sheila Rowan, Director of the Institute for Gravitational Research at the University of Glasgow. Plus Dr Robert Massey takes on your questions and shares his stargazing tips for spring.