There's something very odd going on in space - something that shouldn't be possible. It is as though vast swathes of the universe are being hoovered up by a vast and unseen celestial vacuum cleaner. Sasha Kaslinsky, the scientist who discovered the phenomenon, is understandably nervous: 'It left us quite unsettled and jittery' he says, 'because this is not something we planned to find'. The accidental discovery of what is ominously being called 'dark flow' not only has implications for the destinies of large numbers of galaxies - it also means that large numbers of scientists might have to find a new way of understanding the universe. Dark flow is the latest in a long line of phenomena that have threatened to rewrite the textbooks. Does it herald a new era of understanding, or does it simply mean that everything we know about the universe is wrong?

This new feature-length biographical film tells the extraordinary and dramatic story of the planet's most famous living scientist, told for the first time in his own words and by those closest to him. Made with unique access to his private life, this is an intimate and moving journey into Stephen Hawking's past and present. Interviewees include Stephen Hawking's sister Mary, his ex-wife Jane, carers and students, as well as colleagues such as Roger Penrose, plus Apollo astronaut Buzz Aldrin, actors Benedict Cumberbatch and Jim Carrey, and Sir Richard Branson This inspirational portrait of an iconic figure relates Hawking's incredible personal journey from boyhood underachiever to scientific genius and multi-million-selling author. And it charts how he overcame being diagnosed with motor neurone disease - and being given just two years to live - to make amazing scientific discoveries and become a symbol of triumph over adversity. Born exactly 300 years after the death of Galileo, Hawking grew up in a family some regarded as eccentric. Always asking questions, he was nicknamed 'Einstein' at school. Hawking blossomed at Oxford, although he only spent an hour a day studying. He noticed that he was becoming clumsy and fell over for no apparent reason. He was diagnosed with motor neurone disease, but nevertheless started a family and embarked on his academic career, finding himself at the heart of a searing scientific debate about the origins of the universe. And as he lost the use of his body, Hawking had to find new ways to think. He went on to write the huge bestseller A Brief History of Time, and the film reveals the high and lows of his resulting fame and fortune.

Can new emission-free electric planes replace our polluting airliners and revolutionize personal transportation in our cities? The film takes a ride in some quiet, energy-efficient, prototypes that are vying for success as electric flight takes off.
The race is on to stop the climate emergency and we're seeing more and more people really paying attention to their carbon footprint. Aviation is a fast-growing offender, but is it too slow to respond. Could rapid progress in electric technology change the equation?

Are the rings of Saturn a real celestial phenomenon or merely a cosmic Illusion? Technology allows the experts to get closer to the furthest planet visible to the naked eye. Old questions are answered and new ones arise. Does Saturn hold the key to Earth's weather and will one of its moons supply us with all the oil we'll ever need?

The climate is changing faster than ever, which is why 'fix our climate' is one of the five goals of the Earthshot Prize. Prince William, Sir David Attenborough and Christiana Figueres highlight inspiring and often unexpected solutions to the challenge. In this film, we'll explain the scale of the problem posed by climate change and will introduce you to some amazing people already working on climate crisis. One of these three finalists will win the Earthshot Prize and get the platform and resources they need to scale their ground-breaking work. Nine more solutions for fixing our climate will receive the same support over the course of this decade.

The episode, devoted to the planet Mars, begins with scientific and fictional speculation about the Red Planet during the late nineteenth and early twentieth centuries (H. G. Wells' The War of the Worlds, Edgar Rice Burroughs' science fiction books, and Percival Lowell's false vision of canals on Mars). It then moves to Robert Goddard's early experiments in rocket-building, inspired by reading science fiction, and the work by Mars probes, including the Viking, searching for life on Mars. The episode ends with the possibility of the terraforming and colonization of Mars and a Cosmos Update on the relevance of Mars' environment to Earth's and the possibility of a manned mission to Mars.