As of 5 July 2016, the United States Strategic Command tracked a total of 17,852 artificial objects in orbit about the Earth, including 1,419 operational satellites. Take a look at the mounting threat of debris in Earth's atmosphere, the potential dangers of such 'junk' and what can possibly be done to avoid a crisis. The film is a visually explosive journey of discovery that weighs the solutions aimed at restoring our planet's orbits.

The second programme deals with the mechanics of flight. Getting into the air is by far the most exhausting of a bird's activities, and Sir Attenborough observes shearwaters in Japan that have taken to climbing trees to give them a good jumping-off point. The albatross is so large that it can only launch itself after a run-up to create a flow of air over its wings. A combination of aerodynamics and upward air currents (or thermals), together with the act of flapping or gliding is what keeps a bird aloft. Landing requires less energy but a greater degree of skill, particularly for a big bird, such as a swan. Weight is kept to a minimum by having a beak made of keratin instead of bone, a light frame, and a coat of feathers, which is maintained fastidiously. The peregrine falcon holds the record for being fastest in the air, diving at speeds of over 300 km/h. Conversely, the barn owl owes its predatory success to flying slowly, while the kestrel spots its quarry by hovering. However, the true specialists in this regard are the hummingbirds, whose wings beat at the rate of 25 times a second. The habits of migratory birds are explored. After stocking up with food during the brief summer of the north, such species will set off on huge journeys southwards. Some, such as snow geese, travel continuously, using both the stars and the sun for navigation. They are contrasted with hawks and vultures, which glide overland on warm air, and therefore have to stop overnight.

Blue whales are the largest animals to ever live on earth, yet they are difficult to find or track. Even some of the locations where they birth their young are great secrets. Join some of the world's eminent blue whale scientists as they embark on a revolutionary mission to identify and tag California blue whales as they migrate to a spot known as the Costa Rica Dome. This incredible voyage yields unforgettable new footage and insight into these amazing creatures' lives. Scientists use DNA analysis, recordings of whale songs, homing devices, and sea dives to shed light on the blue whale's breeding and birthing habits

Journeying from pole to pole, The series 'Frozen Planet II' reveals surprising worlds that exist across the planet and the remarkable animals that make them their home. In a fragile world of beauty and hostility, nature finds a way to survive and thrive. David Attenborough explores a planet on the brink of major change.
In the first episode, we begin our journey in the far south, in the most hostile place on earth, the frozen continent of Antarctica. After being raised on the ice in winter, emperor penguin chicks find themselves abandoned by their parents in spring. To survive, they must find their own way across the treacherous sea ice to the rich waters of the Southern Ocean.
The waters surrounding Antarctica may be the richest of all, but they are also home to an exceptionally sophisticated predator, the killer whale. To reach their favored prey, Weddell seals, a family of killer whales have learnt to generate their own waves, washing the seals off their ice floes. It’s a technique that has been passed down over generations and is coordinated by the family matriarch, who can be over 100 years old.
Leaving Antarctica and travelling north, we discover frozen habitats that are created by altitude. The greatest of these is the Himalaya, the tallest mountain range on earth, which contains so much ice and snow it is known as the third pole. In the shadow of the Himalaya lies a vast frozen grassy plain that is home to the fluffiest cat in the world, Pallas’s cat. It may have extremely dense fur, but if it’s to survive the Mongolian winter, it needs to catch lots of gerbils and voles. Easier said than done when you only have short legs and paws that are sensitive to the cold.
North of the Great Steppe lies the boreal forest, which encircles the continents of North America, Europe and Asia, and remains frozen for six months of the year. Prowling these forests in the far east of Russia is the Siberian tiger, the largest cat in the world. In winter, it is on the lookout for black bears hibernating in caves, a high-risk strategy that only a cat of this size would attempt.
Above the boreal forest, we cross into the Arctic Circle, where conditions become so extreme that trees can no longer grow. This is the tundra. Living here are relics of the last ice age, musk ox. In spring, their calves face a far greater danger than the cold, grizzly bears. Encounters can be brutal, but if just a few calves survive the gauntlet, the herd’s future is secure.
To the north of the tundra is the Arctic Ocean, the only ocean that can completely freeze over. Living here is one of the most peculiar animals on earth, the hooded seal. Males have extraordinary inflatable noses, producing a bright red balloon out of their left nostrils. One male hopes this will make him irresistible.
All of the frozen habitats share one thing in common: the threat posed by today’s climate change. Travelling to the island of Greenland, home to the largest body of ice in the northern hemisphere, we witness how global warming is melting its ice cap at faster rates than ever before, with profound consequences for global sea levels. Lastly, we visit the Arctic’s most iconic resident, the polar bear, as a mother bear struggles to provide for her cubs in a world of shrinking sea ice.

This episode includes footage of wildlife inhabiting underwater kelp forests, thousands of giant cuttlefish spawning along a restricted area of rocky reef off the south coast of Australia. Males outnumber females 11 to one, which leads to fierce competition. Larger males use brute force to drive off competition, while their smaller rivals use deception by mimicking the appearance of females. The programme also features tiger sharks hunting for green turtles in fields of seagrass and spider crabs trying to avoid predators while they shed their shells.

Join scientists as they grab light from across the universe to prove quantum entanglement is real. Einstein called it 'spooky action at a distance,' but today quantum entanglement is poised to revolutionize technology from computers to cryptography. Physicists have gradually become convinced that the phenomenon—two subatomic particles that mirror changes in each other instantaneously over any distance is real. But a few doubts remain.
The film follows a ground-breaking experiment in the Canary Islands to use quasars at opposite ends of the universe to once and for all settle remaining questions.