All good travel guides need a map, and the team unveil the most detailed 3-D map of the Milky Way ever produced. A map that reveals that there may be 50 per cent more stars in the galaxy than we previously thought. American astronomer Neil deGrasse Tyson gives us a guided tour of the strangest stars we have ever observed, and we discover that the Milky Way may already be colliding with our neighbouring galaxy, Andromeda.

When the first episode of The Sky at Night was transmitted in April 1957, it was still thought that Mars could be home to advanced life, the Space Age was yet to begin, and the Big Bang was just a controversial theory. So to celebrate its 60th anniversary, this special programme looks at how our knowledge of the universe has been transformed in the last six decades - from the exploration of the solar system to the detection of black holes and planets orbiting distant stars. Featuring contributions from Jim Al-Khalili, Dallas Campbell and Monica Grady and including special birthday messages from a host of stars, this is a celebration of an extraordinary age of discovery, and The Sky at Night's role in covering it.