Tim takes a celestial journey to discover what makes the planets of our solar system so different from one another, and finds out how our closest neighbour Venus was once like earth.
Tim investigates what stars are made of, how long they live and what happens when they die. Plus the latest amazing images from the James Webb space telescope.
Tim recalls one of the most daunting moments of a mission - his first space walk - and explores life onboard the space station, coping with weightlessness, space food... and going to the loo.