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.