Why will astronauts' footprints stay on the moon forever? What is the furthest distance an artificial object lies in space? How can you help search for intelligent life on other planets? For thousands of years, humans have looked into the darkness of space and dreamed of exploring worlds beyond their own. 'Outer Space' investigates the frontiers beyond Earth: from the discovery of the planets in our solar system, through the first moon landing, to the probes that are now travelling into deep space.