Every year, around the world, seasonal changes transform entire landscapes and draw in millions of creatures as these great events unfold. This fantastic series combines the epic scale of Planet Earth and the intimate, emotional stories of charismatic animals as they struggle to survive. Using state of the art technology, these programmes capture the Earth's most dramatic and epic wildlife spectacles and the intimate stories of the animals caught up in them.
The Great Melt: The summer melt of Arctic ice, opening up nearly three million square miles of ocean and land, provides opportunities for millions of animals, including beluga whales, families of Arctic foxes, vast colonies of seabirds, and the fabled Arctic unicorn, the narwhal. For polar bears, however, it is the toughest time of year. Why? How will they survive? A mother polar bear and her cub make their first journey together onto the sea ice. They are looking for ringed seals, their favourite prey. It is a serious business but the cub just wants to play. The melting ice makes it harder for them to hunt and threatens their survival. In a unique aerial sequence, the migration of narwhal with their distinctive unicorn-like tusks is filmed for the first time. The whales' journey is risky as they travel along giant cracks in the ice. If the ice were to close above them, they would drown. Hundreds of beluga whales gather in the river shallows. They rub themselves on smooth pebbles in one of the most bizarre summer spectacles. Guillemot chicks take their first flights from precipitous sea cliff nests to the sea 300 metres below. They attempt to glide to safety but many miss their target. Their loss is a bonus for the hungry Arctic fox family waiting below. As the melt comes to an end the bears gather, waiting for the sea to freeze again. Two 400kg males square up to each other to spar.

Each year more than one million wildebeest and zebra invade the Serengeti grasslands, making it a paradise for the predators that live there. But what happens when the herds move off again? We follow the moving story of one lion family's struggle to survive until the return of the great migration. Nature's Great Events tells the story of the epic trek of herds that follow the rains to fresh pastures, and the tale of the predators they leave behind.
The crew captures the desperate plight of a single pride of lions, revealing a different side to the Serengeti. Rather than being a predators' paradise, it is a land in constant change, with wildebeest following the rains and leaving the lions to tough it out. The Ntudu pride has seven cubs, and is already suffering as the wildebeest leave to find fresh pastures. The four pride females struggle to find enough food for their hungry offspring. As weeks turn to months, the pride members become more emaciated and frailer, and the number of cubs dwindles to just two. As the herds begin to return, the plains reveal one final secret. For the first time since 1967 the Serengeti's only active volcano, Ol Doinyo Lengai, begins to billow ash and smoke. Filmed from the air, the team captures the exciting action. Fertilised by the volcanic ash over millions of years, these short grass plains are among the most productive grasslands in the world. After months of hardship, the pride's tragic story, through sickness, drought and fire, is over as the herds return, providing plentiful food.

The great flood in the Okavango turns 4,000 square miles of arid plains into a beautiful wetland. Elephant mothers guide their families on an epic trek across the harsh Kalahari Desert towards it, siphoning fresh water from stagnant pools and facing hungry lions. Hippos battle for territory, as the magical water draws in thousands of buffalo and birds, and vast clouds of dragonflies. Will the young elephant calves survive to reach this grassland paradise? The experienced mother elephants time their arrival at the delta to coincide with the lush grass produced by the great flood.
In a TV first, the programme shows the way they use their trunks to siphon clean water from the surface layers of a stagnant pool, while avoiding stirring up the muddy sediment on the bottom with their feet. Lechwe swamp deer, zebras, giraffes, crocodiles and numerous fish and thousands of birds arrive in the delta. And, in a phenomenon never before filmed in the Okavango, thousands of dragonflies appear - seemingly from nowhere - within minutes of the flood arrival, mating and laying eggs. As the flood finally reaches its peak, elephants and buffalo, near the end of their epic trek across the desert, face the final gauntlet of a hungry pride of lions. In a heart-wrenching sequence, a baby elephant is brought down by a lion in broad daylight.

Every summer in the seas off Alaska humpback whales, sea lions and killer whales depend on an explosion of plant life, the plankton bloom. It transforms these seas into the richest on Earth. But will these animals survive to enjoy the great feast? The summer sun sparks the growth of phytoplankton, microscopic floating plants which can bloom in such vast numbers that they eclipse even the Amazon rainforest in sheer abundance of plant life. Remarkably, it is these minute plants that are the basis of all life here. But both whales and sea lions have obstacles to overcome before they can enjoy the feast. Humpback whales migrate 3,000 miles from Hawaii, and during their 3 month voyage lose a third of their body weight. In a heart-rending scene a mother sea lion loses her pup in a violent summer storm, while another dramatic sequence shows a group of killer whales working together to kill a huge male sea lion.
In late summer the plankton bloom is at its height. Vast shoals of herring gather to feed on it, diving birds round the fish up into a bait ball and then a humpback whale roars in to scoop up the entire ball of herring in one huge mouthful. When a dozen whales work together they employ the ultimate method of co-operative fishing - bubble net feeding. One whale blows a ring of bubbles to engulf the fish and then they charge in as one. Filmed from the surface, underwater and, for the first time, from the air, we reveal how these giant hunters can catch a tonne of fish every day.

When man finally broke free of the Earth's gravitational pull the dream of travelling to other planets became a reality. Today scientists are proposing a bizarre array of technologies in the hope of travelling faster through space: from space craft sporting sails that catch laser beams, to propulsion engines powered by a bizarre entity known as anti-matter. Finally explore the science behind the seemingly fanciful notion of warp-drive and a theoretical particle that can travel faster than light.

A stellar explosion, the supernova is the sensational death of a star. It can shine as bright as 100 billion Suns and radiate as much energy as the Sun would emit over 10 billion years. Jets of high-energy light and matter are propelled into space and can cause massive Gamma Ray Bursts and emit intense X-ray radiation for thousands of years. Astronomers believe that this process creates the very building blocks of planets, people and plants. Meet the world's leading Supernova hunters, and take a look at recorded supernovas throughout history.