In two billion years' time our own Milky Way will collide with another galaxy, Andromeda, which will rip apart the fabric of both galaxies, destroying stars and planets and sparking a shockwave of fiery rebirth. Patrick Moore anticipates this far-off event and explains the role that 'dark matter' will play in this cosmic collision. Dr Chris Lintott steps outside to look at Andromeda, easily visible in the night sky using binoculars.

Dr Chris Lintott finds out how British technology is leading the way in satellite science, while Sir Patrick Moore investigates the threat from space debris that astronauts face in space.