The Sky at Night looks back at the last ten years of astronomy and ponders the most significant milestones and revelations. With the help of six distinguished astronomers, Chris and Maggie consider the state of astronomy in 2020 and wonder what new, exciting discoveries await us across the rest of the decade, as a host of new ground and space telescopes come online. Astronomer Royal Lord Martin Rees is among the guests to walk along the Astronomical Wall of Discovery in this one-hour special.

Looking back on the major stories of the year - from the New Horizons mission to the most distant world we have ever visited to the release of the first-ever picture of a black hole. The team relive the highlights and uncover the latest developments.

This is the story of two of the biggest scientific breakthroughs of the 21st century, told by the incredible scientists who made them happen. The first is LIGO’s measurement of gravitational waves coming from a black hole merger, and the second, the Event Horizon Telescope’s image of a black hole.