Dr Knowles and Professor McCork ask the question 'What is a black hole?' and we find out some very weird and wonderful things about gravity and the black holes in space that suck in everything that crosses their path! It's a massive day for Professor McCork and Dr Knowles as it's the first ever live Brain Freeze OB - from space! Hoping that the team will understand the gravity of the event, Colin mans the fort at the studio and Ms Hucklebuck tries to stay grounded.