Dinosaurs ruled the earth for 150 million years, then suddenly they were gone. Their disappearance is one of the planet’s greatest mysteries – unimaginable, until now. The film proposes a minute-by-minute chronology of the Chicxulub impact and its effect on the dinosaurs and other animals around the world. A blow-by-blow account of the cataclysm that ended the reign of the dinosaurs, and forever changed the course of life on Earth.

For the animals in the polar regions, autumn means dramatic battles and epic journeys. Time is running out - the Arctic Ocean is freezing over and the sea ice is advancing at 2.5 miles per day around Antarctica. Polar bears gather in large numbers on the Arctic coast as they wait for the return of the ice. Soon, tempers fray and violent sparring contests break out. Meanwhile 2,000 beluga whales head for one special estuary, a gigantic 'whale spa' where they will thrash their snow-white bodies against the gravel and exfoliate. Inland, the tundra undergoes a dramatic transformation from green to fiery red. Here, musk ox males slam head-first into each other with the force of a 30mph car crash as they struggle to defend their harems. Frisky young caribou males play a game of 'grandma's footsteps' as they try to steal the boss's female. Down in Antarctica, Adelie penguin chicks huddle together in creches. When a parent returns from fishing, it leads its twins on a comical steeplechase - sadly there's only enough for one, so the winner gets the meal. Two months later and the chicks are fully feathered apart from downy Mohican hairdos - they're ready to take their first swim - reluctantly though, as it seems penguins are not born with a love of water! And with good reason - a leopard seal explodes from the sea and pulls one from an ice floe, a hunting manoeuvre that has never been filmed before. As winter approaches and everyone has left, the giant emperor penguin arrives and makes an epic trek inland to breed. The mothers soon return to the sea leaving the fathers to hold the eggs and endure the coldest winter on earth.

The documentary series reveals the extraordinary riches and wonders of the Polar Regions that have kept people visiting them for thousands of years. Today, their survival relies on a combination of ancient wisdom and cutting-edge science. Most Arctic people live in Siberia, either in cities like Norilsk - the coldest city on earth - or out on the tundra, where tribes like the Dogan survive by herding reindeer, using them to drag their homes behind them. On the coast, traditional people still hunt walrus from open boats - it is dangerous work, but one big walrus will feed a family for weeks. Settlers are drawn to the Arctic by its abundant minerals; the Danish Armed Forces maintain their claim to Greenland's mineral wealth with an epic dog sled patrol, covering 2,000 miles through the winter. Above, the spectacular northern lights can disrupt power supplies so scientists monitor it constantly, firing rockets into it to release a cloud of glowing smoke 100 kilometres high. In contrast, Antarctica is so remote and cold that it was only a century ago that the first people explored the continent. Captain Scott's hut still stands as a memorial to these men. Science is now the only significant human activity allowed; robot submarines are sent deep beneath the ice in search of new life-forms, which may also be found in a labyrinth of ice caves high up on an active volcano. Above, colossal balloons are launched into the purest air on earth to detect cosmic rays. At the South Pole there is a research base designed to withstand the world's most extreme winters. Cut off from the outside world for six months, the base is totally self-sufficient, even boasting a greenhouse.

Spring arrives in the polar regions, and the sun appears after an absence of five months; warmth and life return to these magical ice worlds - the greatest seasonal transformation on our planet is underway. Male Adelie penguins arrive in Antarctica to build their nests - it takes a good property to attract the best mates and the males will stop at nothing to better their rivals! But these early birds face the fiercest storms on the planet. In the Arctic, a polar bear mother is hunting with her cubs. Inland, the frozen rivers start to break up and billions of tons of ice are swept downstream in the greatest of polar spectacles. This melt-water fertilizes the Arctic Ocean, feeding vast shoals of Arctic cod and narwhal. The influx of freshwater accelerates the breakup of the sea-ice - an area of ice the size of Australia will soon vanish from the Arctic. On land, a woolly bear caterpillar emerges from the snow having spent the winter frozen solid. Caterpillars normally become moths within months of hatching, but life is so harsh here that the woolly bear takes 14 years to reach adulthood. Once mature it has only days to find a mate before it dies! Alongside the caterpillars white Arctic wolves race to raise their adorable cubs before the cold returns.

This is one of the most ambitious animated programmes ever attempted for broadcast TV, recreating every detail of these extraordinary animals in an entirely digital production that stretches the boundaries of broadcast 3D with a scale and ambition normally reserved for Hollywood feature films. Planet Dinosaur 3D is a thrilling and immersive journey into a lost world. Pulling together cutting edge research from around the world this programme uses the latest, stunning fossil evidence to chart the rise and fall of the 'Ultimate Killers'; from the iconic Spinosaurus, the largest predator ever to walk the Earth, to Microraptor and the feathered, flying dinosaurs from China. At last, thanks to the advances in technology, and for the first time ever, these monsters can be experienced in all their full, magnificent wonder.

This episode is centered around how science, in particular the work of Clair Patterson (voiced in animated sequences by Richard Gere[33]) in the middle of the 20th century, has been able to determine the age of the Earth. Tyson first describes how the Earth was formed from the coalescence of matter some millions of years after the formation of the Sun, and while scientists can examine the formations in rock stratum to date some geological events, these can only trace back millions of years. Instead, scientists have used the debris from meteor impacts, such as the Meteor Crater in Arizona, knowing that the material from such meteors coming from the asteroid belt would have been made at the same time as the Earth. Patterson also examined the levels of lead in the common environment and in deeper parts of the oceans and Antarctic ice, showing that lead had only been brought to the surface in recent times. He would discover that the higher levels of lead were from the use of tetraethyllead in leaded gasoline resulting in government-mandated restrictions on the use of lead.