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.

2020 has been an unprecedented year in science. From a global pandemic and race to find a cure, to exploring our planetary neighbours and our own world, stay in the know with the latest stories that defined this tumultuous year. 365 days marked by stark warnings about the planet's future and technological triumphs. During this journey around the sun, science continued to reveal stories of our past and also provide promise that we can overcome the obstacles in way some far ahead and others more immediate.

Chris Lintott and Maggie Aderin-Pocock report on the reaction to the dramatic announcement of the discovery of phosphine gas in the clouds of Venus, a gas that could be a sign of life. Venus remains an inhospitable and unlikely host. But if not Venus, where in the solar system is the best place to look for alien life? Chris and Maggie investigate the latest missions to Mars and the icy moons of Jupiter and Saturn. Away from the search for life, Pete Lawrencepreviews the best meteor showers of the year.

Five times, the Earth has faced apocalyptic events. Cataclysms that have swept away all life forms, or almost. Each time, a handful of species has survived, establishing a new world. What did these prehistoric worlds look like? What catastrophes led to their disappearance? How did our distant ancestors manage to survive the five mass extinctions that the Earth has suffered, finally giving rise to the world we know today?
Combining CGI of ancient animal and plant life, VFX and filming, 'Prehistoric Worlds' looks back at the five mass extinctions of life on Earth that allowed the advent of the human race. On the brink of a sixth mass extinction that the scientific community considers imminent – this time caused by mankind – this film gives us an interesting and powerful look at Man's existence on the scale of the history of our planet.

What sort of alien civilizations might exist in the vastness of space? Terra is the fictional world imagined in Episode 4, a planet nine billion years old, twice as old as Earth. Old enough that a truly advanced intelligence could evolve. It was once a fertile world, now it is barren. But life can still thrive here in artificial domes. Over time, they've evolved not to need their bodies. They exist only as neural tissue. They never age, they never die. They're monitored and maintained by robots.
If alien civilizations are statistically so likely, why haven't astronomers found any sign of them? Where is everyone? Every time we look at an individual star, that's like dropping a bucket in the ocean. We're going to have to look at a lot of stars and to search through a lot of data until we find the clue that leads us to another civilization.

Planets beyond our solar system are known to astronomers as exoplanets. They are at trillions of miles from Earth and yet, it might be possible to detect a faint signature of life in them. From the light of the stars they orbit that passes through the atmosphere of an exoplanet, it is possible to capture the chemical fingerprint of the elements in that atmosphere.
The fictional world Eden is orbiting not one star, but two. The light from its twin stars powers photosynthesis, pumping more oxygen into the atmosphere than in Earth, allowing life to thrive. Grazers are constantly alert to danger, because the canopy is home to predators perfectly evolved to live among the trees. In Episode 3, another topic are fungi and the role they could play on exoplanets. Ecologist Thomas Crowther talks about the role mycelial networks play in the Rothiemurchus forest in Scotland.