For past three and a half years, ESA's Gaia Space telescope has been mapping the heavens in unprecedented detail. At the end of April 2018 it released precise data on over 1.3 billion stars in the Milky Way showing how they move over time and their distance from Earth. Maggie and Chris reveal some of the most surprising initial findings, from the discovery of wandering black holes, hyper velocity stars and 'transient phenomena' to a brand new age map of the Milky Way and concrete evidence of how our galaxy formed.

Chris Lintott uses the Sky at Night archive to reveal the deepest secrets of galaxies, from their earliest beginnings to their very ends.