Every year grizzly bear families in North America depend for their survival on a spectacular natural event: the return of hundreds of millions of salmon from the Pacific Ocean to the mountain streams where they were born. The salmon travel thousands of miles to spawn and then die. The great run not only provides food for bears, but for killer whales, wolves, bald eagles, and even the forest itself. The question is: will the salmon return in time to keep hungry bears alive?
A mother grizzly and her cubs emerge from their den high in snowy Alaskan mountains. Filming from the air the team capture a TV first, following the bears as they negotiate a near vertical slope on their journey to the coast where they await the return of the salmon. Meanwhile, the salmon are making their way to the to river mouths where they must swim upstream and against the current. The programme reveals how they tackle the torrents and leap over waterfalls, a feat equivalent to a human jumping over a house. Dozens of hungry bears eagerly await the salmon that make it up river. In another TV first, underwater cameras record the ingenuity and fancy footwork they use to collect dead salmon from the bottom of deep pools.

There is a contest each year that can change a young skater's life. There are no pros with million dollar endorsement deals here, just real kids with real lives and everything on the line. This is the story of a few of the best, from France, Brazil and the USA, as they risk everything for a chance of a lifetime. Motivation 3: The Next Generation is a proper follow-up to The Motivation but this time the stakes are so much higher. We're in deep with real kids escaping poverty and violence, crashing in skate-houses or still living with mom. For all of these kids a win at Tampa Am could mean a way out and an opportunity to do what they love for a living-skate.

Dr Janina Ramirez unlocks the secrets of illuminated manuscripts that were custom-made for kings and explores the medieval world they reveal. 'Ruling by the Book.' Janina begins her journey with the first Anglo-Saxon rulers to create a united England, encountering books in the British Library's Royal manuscripts collection which are over a thousand years old and a royal family tree which is five metres long.
Janina finds out about a king who had a reputation for chasing nuns and reads a book created as a wedding gift for a ten-year-old prince. She roams from Westminster Abbey to other ancient English spiritual sites such as Winchester, St Albans and Malmesbury, and sees for herself how animal skins can be transformed into the finest vellum.

A look at two missions attempting one of the most difficult feats of space exploration - to collect a rock from another world. The film checks in on the US and Japanese attempts to bring a piece of an asteroid back to Earth. The missions have taken decades of planning, but the results will be worth it. We find out how studying these space rocks can teach us about the origins of our solar system and may one day help save Earth from a catastrophic collision.

The film the tells the life of Jamaican sprinter and three times Olympic gold medalist and World Record holder for 100m, 200m and 4x100m, Usain Bolt, the fastest man in recorded human history. It describes Bolt's journey in winning nine gold medals and the incidents surrounding the Olympic titles. Featuring interviews with famous athletes like Pelé, Neymar, and Serena Williams, the film examines multiple world-record holder Bolt's rise to dominance and the the legacy of the fastest man ever timed.

This documentary journeys with the scientists into the heart of a giant. Juno is the Nasa mission designed to peer through Jupiter's swirling clouds and reveal the wonders within. By projecting a 70-foot-wide, life-size Juno on a Houston rooftop, Scott Bolton, head of Juno, shows us how its fragile electronics are encased in 200kg of titanium. As Scott puts it, 'we had to build an armoured tank to go there.' Professor Andrew Ingersoll, Juno's space weatherman, reveals they have seen lightning inside Jupiter, perhaps a thousand times more powerful than Earth's lightning. This might be evidence for huge quantities of water inside Jupiter.
Under the extreme conditions of Jupiter thousands of miles under the surface, hydrogen becomes a liquid metal. Juno is finding out how much liquid metallic hydrogen is inside Jupiter, and scientists hope to better understand how this flowing metal produces the most powerful aurora in the Solar System. But what is at Jupiter's heart? In Nice, Prof Tristan Guillot explains how Juno uses gravity to map the planet's centre. This can take scientists back to the earliest days of the solar system, because Jupiter is the oldest planet and it should contain clues to its own creation. By chalking out an outline of the Jupiter, Tristan reveals there is a huge rocky core - perhaps ten times the mass of Earth.