Star Trails and the Bracewell Radio Sundial
* Image Credit & Copyright: Miles Lucas at NRAO

Explanation:
Sundials use the location of a shadow to measure the Earth's rotation and indicate the time of day. So it's fitting that this sundial, at the Very Large Array Radio Telescope Observatory in New Mexico, commemorates the history of radio astronomy and radio astronomy pioneer Ronald Bracewell. The radio sundial was constructed using pieces of a solar mapping radio telescope array that Bracewell orginaly built near the Stanford University campus. Bracewell's array was used to contribute data to plan the first Moon landing, its pillars signed by visiting scientists and radio astronomers, including two Nobel prize winners. As for most sundials the shadow cast by the central gnomon follows markers that show the solar time of day, along with solstices and equinoxes. But markers on the radio sundial are also laid out according to local sidereal time. They show the position of the invisible radio shadows of three bright radio sources in Earth's sky, supernova remnant Cassiopeia A, active galaxy Cygnus A, and active galaxy Centaurus A. Sidereal time is just star time, the Earth's rotation as measured with the stars and distant galaxies. That rotation is reflected in this composited hour-long exposure. Above the Bracewell Radio Sundial, the stars trace concentric trails around the north celestial pole.

https://apod.nasa.gov/apod/ap180713.html

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Frozen Planet

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YEAR: 2011 | LENGTH: 7 parts (50 minutes each) | SOURCE: BBC

description:

The seven-part series focuses on life and the environment in both the Arctic and Antarctic. The production team were keen to film a comprehensive record of the natural history of the polar regions, because climate change is affecting landforms such as glaciers, ice shelves, and the extent of sea ice. The film was met with critical acclaim and holds a Metacritic score of 90/100. Despite such, it has been criticized for limited coverage of the effects of global warming and attribution of recent climate change.

episodes:

01. To the Ends of the Earth

David Attenborough travels to the end of the Earth, taking viewers on an extraordinary journey across the polar regions of our planet, North and South. The Arctic and Antarctic are the greatest and least known wildernesses of all – magical ice worlds inhabited by the most bizarre and hardy creatures on Earth.

Our journey begins with David at the North Pole, as the sun returns after six months of darkness. We follow a pair of courting polar bears, which reveal a surprisingly tender side. Next stop is the giant Greenland ice cap, where waterfalls plunge into the heart of the ice and a colossal iceberg carves into the sea. Humpback whales join the largest gathering of seabirds on Earth to feast in rich Alaskan waters. Further south, the tree line marks the start of the taiga forest, containing one third of all trees on earth. Here, 25 of the world’s largest wolves take on formidable bison prey.

At the other end of our planet, the Antarctic begins in the Southern Ocean, where surfing penguins struggle to escape a hungry sea lion and teams of orcas create giant waves to wash seals from ice floes – a filming first. Diving below the ice, we discover prehistoric giants, including terrifying sea spiders and woodlice the size of dinner plates. Above ground, crystal caverns ring the summit of Erebus, the most southerly volcano on earth. From here, we retrace the routes of early explorers across the formidable Antarctic ice cap – the largest expanse of ice on our planet. Finally, we rejoin David at the South Pole, exactly one hundred years after Amundsen, then Scott, were the first humans to stand there.

02. Spring

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 under way.

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.

In Antarctica, vast numbers of seabirds arrive on South Georgia joining the giant albatross and king penguins that have been there all winter. Elephant seals fight furious battles over females on a beach that contains the greatest mass of animals on the planet.

Finally, the female Adelie penguins arrive, chased from the water by killer whales. Mating and chick rearing lie ahead of them.

03. Summer
It is high summer in the polar regions, and the sun never sets. Vast hordes of summer visitors cram a lifetime of drama into one long, magical day; they must feed, fight and rear their young in this brief window of plenty. Summer is a tough time for the polar bear family, as their ice world melts away and the cubs take their first swimming lesson. Some bears save energy by dozing on icy sun beds, while others go egg-collecting in an Arctic tern colony, braving bombardment by sharp beaks. There are even bigger battles on the tundra; a herd of musk oxen gallop to the rescue as a calf is caught in a life and death struggle with a pair of Arctic wolves. But summer also brings surprises, as a huge colony of 400,000 king penguins cope with an unlikely problem – heat. The adults go surfing, while the woolly-coated chicks take a cooling mud bath. Nearby, a bull fur seal is prepared to fight to the death with a rival. Fur flies as the little pups struggle desperately to keep out of the way of the duelling giants. Further south, a minke whale is hunted amongst the ice floes by a family of killer whales. The dramatic chase lasts over 2 hours and has never been filmed before. The killers harry the minke whale, taking it in turns to wear it down. Eventually it succumbs to the relentless battering. Finally, comical adelie penguins waddle back to their half a million strong colony like clockwork toys. The fluffy chicks need constant feeding and protection as piratical skuas patrol the skies. When an unguarded chick is snatched, a dramatic “dogfight” ensues.

04. Autumn

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.

05. Winter

There is no greater test for life than winter, as temperatures plummet to 70 below and winds reach 200kph. Darkness and ice extend across the polar regions and only a few remarkable survivors gamble on remaining.

We join a female polar bear trekking into the Arctic mountains to give birth as the first blizzards arrive. Out on the frozen ocean, the entire world’s population of spectacled eider ducks brave the winter in a giant ice hole kept open by ferocious currents. Arctic forests transform into a wonderland of frost and snow – the scene of a desperate and bloody battle between wolf and bison, but also where a remarkable alliance between raven and wolverine is made. Beneath the snow lies a magical world of winter survivors. Here tiny voles dodge the clutches of the great grey owl, but cannot escape the ultimate under-show predator – the least weasel.

Midwinter and a male polar bear wanders alone across the dark, empty icescape. Below the snow, polar bear cubs begin life in an icy den while fantastical auroras light the night skies above. In Antarctica, we join male emperor penguins in their darkest hour, battling to protect precious eggs from fierce polar storms. Weddell seals escape to a hidden world of jewel-coloured corals and alien-looking creatures but frozen devastation follows as sinister ice stalactites reach down with deadly effect.

The sun finally returns, and with it comes the female emperor penguins, sleek and fat, ready to deliver the first meal to their precious chick. Having survived winter, this ultimate ice family now have a head start in raising baby. The Adelies flood back and as the ice edge bustles with life, male emperor penguins can finally return to the sea.

06. The Last Frontier

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.

07. On Thin Ice

David Attenborough journeys to both polar regions to investigate what rising temperatures will mean for the people and wildlife that live there and for the rest of the planet.

David starts out at the North Pole, standing on sea ice several metres thick, but which scientists predict could be open ocean within the next few decades. The Arctic has been warming at twice the global average, so David heads out with a Norwegian team to see what this means for polar bears. He comes face-to-face with a tranquilised female, and discovers that mothers and cubs are going hungry as the sea ice on which they hunt disappears. In Canada, Inuit hunters have seen with their own eyes what scientists have seen from space; the Arctic Ocean has lost 30% of its summer ice cover over the last 30 years. For some, the melting sea ice will allow access to trillions of dollars worth of oil, gas and minerals. For the rest of us, it means the planet will get warmer, as sea ice is important to reflect back the sun’s energy. Next David travels to see what is happening to the ice on land: in Greenland, we follow intrepid ice scientists as they study giant waterfalls of meltwater, which are accelerating iceberg calving events, and ultimately leading to a rise in global sea level.

Temperatures have also risen in the Antarctic – David returns to glaciers photographed by the Shackleton expedition and reveals a dramatic retreat over the past century. It is not just the ice that is changing – ice-loving adelie penguins are disappearing, and more temperate gentoo penguins are moving in. Finally, we see the first ever images of the largest recent natural event on our planet – the break up of the Wilkins Ice Shelf, an ice sheet the size of Jamaica, which shattered into hundreds of icebergs in 2009.

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Frozen Planet 2Blue Planet 2The Blue PlanetSeven Worlds, One PlanetPlanet EarthSouth Pacific

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Nature’s Great Events

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YEAR: 2009 | LENGTH: 6 parts (60 minutes each) | SOURCE: WIKIPEDIA

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Nature’s Great Events is a wildlife documentary series made for BBC television, first shown in the UK on BBC One and BBC HD in February 2009. The series looks at how seasonal changes powered by the sun cause shifting weather patterns and ocean currents, which in turn create the conditions for some of the planet’s most spectacular wildlife events. Each episode focuses on the challenges and opportunities these changes present to a few key species.

Nature’s Great Events was produced by the BBC Natural History Unit in association with the Discovery Channel and Wanda Films. The British version of the series was narrated by David Attenborough. In the USA, the series was shown under the alternative title Nature’s Most Amazing Events beginning on 29 May 2009[1] and was narrated by Hasani Issa.[2] In Australia, this program began airing on ABC1 each Sunday at 7:30pm from 14 June until 19 July 2009.

The title Nature’s Great Events was previously used by Reader’s Digest for a unrelated VHS series released in 1996

episodes:

01. The Great Melt
The opening episode shows how different species respond to the annual summer thaw of sea ice in the Arctic. The extent of the melt has been increasing in recent times, and this could be disastrous for polar bears. A mother emerges from her winter den with cubs, and leads them on to the sea ice to hunt. As the ice breaks up, the bears have difficulty walking and resort to swimming between floes. For others, it’s a race to breed in the short summer season. When guillemots arrive at their nesting cliffs, the rocks are still cloaked in ice. A few short weeks later, the young launch themselves on their maiden flights, but those that crash before they reach open water present an easy meal for an Arctic fox mother and her cubs. Aerial footage shows the arrival of belugas and narwhals at the edge of the sea ice. The narwhals navigate their way along leads, but can become trapped if the ice ahead is still unbroken. In the height of summer, large parts of the Arctic Ocean are virtually ice-free, leaving some polar bears stranded on the few remaining icebergs. Those that reach dry land must wait for the winter ice to return before they can start hunting again. As the bears congregate, fights break out between the males. Nature’s Great Events Diaries follows the camera team’s attempts to locate narwhals in “Quest for Ice Whales”.

02. The Great Salmon Run
The subject of the second programme is the annual salmon run on the west coast of North America. Hundreds of millions of Pacific salmon return to the mountain streams in which they were born, where they will spawn and then die. Their passage upstream is fraught with danger, from rapids, waterfalls and hungry grizzly bears. The programme begins at the arrival of spring, with a grizzly mother leading her cubs down from their winter den in the Alaskan mountains. The bears congregate in the forested valleys, where they forage for whatever food they can find. Survival is tough for all, as shown by a pack of hungry wolves attacking an adult grizzly. It is not until July that the salmon arrive in great numbers. Other predators join the feast, including Orcas, Stellar sea Lions, Salmon sharks and the Bald headed Eagle. Those that make it past the bears risk becoming trapped in shallow reaches as the water level subsides. Relief comes as a summer storm replenishes the streams, triggered by moist ocean air rising over the coastal mountains. As they reach the spawning grounds, the salmon change body shape and colour in preparation for spawning. When it is over, the fish are close to exhaustion and they die en masse, providing an easy meal for birds and lingering bears. Their deaths are not in vain, for the nutrients from their decaying bodies help to fertilise the soil, sustaining the forests of tall pines. The diary piece, “Close Encounters of a Grizzly Kind”, reveals how footage of the bears fishing using their feet was obtained.

03. The Great Migration
The third installment follows a year in the life of the Ndutu lion pride, which occupies a territory on the short-grass plains of the Serengeti. Their lives are dictated by the annual migration of one million wildebeest and zebra around the Serengeti. As the herds move north following the rains, the Ndutu pride’s four lionesses and seven cubs are left behind to face the dry season without their main prey. The grass dies off leaving the lions without cover, making hunting what few animals remain even more difficult. The pride must keep moving to find food, but gradually the starving cubs weaken. A female cub and her brother, both in very poor condition, cannot keep up with the adults, and their fate seems sealed. However, when the pride is relocated the following month, the two cubs have somehow survived and been reunited with the adults. The lions face a further challenge as the active volcano Ol Doinyo Lengai erupts for the first time since 1967, raining ash down on the plains. These cyclical eruptions play a crucial role in the Serengeti ecosystem. The ash fertilises the earth, and with the arrival of the first storms, the plains become green and lush. The wildebeest herds return and give birth to their young, and the Ndutu pride can enjoy the good times again. In “Pride and Peril”, the diary segment, cameraman Owen Newman’s long and lonely vigil watching the Ndutu pride is rewarded with a story of hardship, loss and fortitude.

04. The Great Tide
Along South Africa’s east coast, the right combination of winter weather and ocean currents trigger the sardine run, one of the most impressive events in the world’s oceans. In recent years, the sardine run has become less predictable, for reasons which are still unclear, bringing into jeopardy an entire food chain which it supports. The fourth programme follows the largest gathering of predators on the planet as they hunt down billions of sardines pinned to the cold water along the coast. They include Cape gannets, which time their breeding to coincide with the arrival of the huge sardine shoals. They are filmed at their breeding colony on Bird Island and in super slow motion breaking the surface on their plunge dives. In the water, a super-pod of 5,000 common dolphins also hunts down the sardines. A 15-mile long shoal is located by the predators, and the ensuing feeding frenzy is filmed from the air, the surface and underwater. Dolphins herd the sardines into the shallows, where they come within reach of the diving gannets. Thousands of sharks arrive to join the attack, but the largest predator of all is the lunging Bryde’s whale. “Life on the Run” follows the fortunes of the film crew as they track the hunters. In 2007, the sardine run didn’t happen at all, but their patience was rewarded the following year.

05. The Great Flood
The fifth installment is set in Botswana, where the arid plains of the Kalahari are transformed into a lush wetland by the annual flooding of the Okavango Delta. The Okavango River is charged by rain falling in the Angolan highlands, but it is months before the water arrives at the delta. Meanwhile, thousands of animals follow ancient migration routes across the desert, braving dehydration and punishing heat. New elephant behaviour is filmed as they skim their trunks delicately across the surface of a stagnant pool, siphoning clean water from the upper layers. The transformation of the desert into a green oasis is filmed using time-lapse photography, whilst sequences shot with macro lenses show the changes in much finer detail. For the first time, vast clouds of dragonflies are observed emerging to mate and lay their eggs. Larger animals make the most of the sudden riches the new landscape offers. Male hippos plough through the newly-formed waterways and battle for dominance, red lechwe bound through the shallows and huge flocks of wading birds arrive to breed. Elephants and buffalo face one final challenge before they reach the delta; a pride of hungry lions. The lions attack in broad daylight, bringing down an elephant calf. The making-of featurette, “Mission Impassable”, follows the crew as they struggle to cross ever-deepening waters to reach and film the front line of the advancing flood.

06. The Great Feast
The final episode features the summer plankton bloom along the coast of British Columbia and Alaska. In winter, the coastal fjords and inlets are relatively lifeless, and the resident Steller sea lions must dive deeper and further from the coast to catch the widely-dispersed herring. Humpback whales overwinter in the warm Pacific waters off Hawaii, where new mothers suckle their calves. They begin their 3,000 mile journey north in early spring, when the sea lions also give birth to their young. Spring storms are a hazard for the sea lion colonies and some pups are inevitably lost, but these same storms disturb nutrients in the water which, together with the strengthening power of the sun, act as the catalysts for the plankton bloom. Huge shoals of herring arrive to spawn, turning the shallows milky white. The herring sift plankton from the water. In their wake come larger predators, including Pacific white-sided dolphins and killer whales. The latter are filmed attacking a male sea lion. Common murres dive under the herring shoals and pick off the fish from below, pinning them to the surface. Their defence is to form a bait ball, but gulls gathering on the surface attack them from above. The finale to the programme features unique underwater footage of humpbacks engulfing whole bait balls, and reveals their co-operative hunting behaviour called bubble-netting. The diary segment, “Swallowed by a Whale”, looks at the challenges of filming the humpbacks and sea lions underwater.

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2022-11-09 23:11:23

Frozen Planet 2

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YEAR: 2022 | LENGTH: 6 parts (~60 minutes each) | SOURCE: BBC

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Life in the extreme. In a fragile world of beauty and hostility, nature finds a way to survive and thrive. Sir David Attenborough explores a planet on the brink of major change.

episodes:

01. Frozen Worlds

Journeying from pole to pole, we reveal the surprising frozen worlds that exist across the planet and the remarkable animals that make them their home.

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 favoured 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.

02. Frozen Ocean

At the top of our planet lies a magical realm, the Arctic Ocean. After four months of winter darkness, the sun returns to reveal a frozen ocean covered in ice. Mother polar bears emerge from their hillside dens and lead their cubs down to the sea ice to hunt, while a young male and female bear forge a surprising friendship out on the ice.

For others, the frozen sea is a trap. A pod of beluga whales has been confined to an ice hole for five months, slowly starving to death as the food around them runs out. Their salvation lies in the strengthening sun that comes with spring, melting the sea ice, allowing their escape.

Off the east coast of Greenland, the floating pack ice in spring is a nursery ground for harp seals. Mothers and pups have just a few weeks together for the pup to learn to swim before she leaves him to fend for himself. But in today’s warming climate, storms can tip helpless youngsters into the sea before they are strong enough to fend for themselves.

Summer is a time of plenty in the Arctic Ocean as plankton blooms feed millions of tiny mouths, such as bizarre skeleton shrimps, as well as the biggest: bowhead whales. These ancient and long-lived whales arrive en masse every year at secret locations known as whale spas. But today, with the loss of summer sea ice, their peace is shattered by orcas from the south. These daring predators are bold enough to take on the much larger bowheads, targeting their vulnerable calves.

The 24-hour daylight of the Arctic summer attracts visitors from afar, including huge flocks of seabirds like crested auklets. A male must use both his song and a secret tangerine perfume if he is to attract a mate. For the resident walrus, the summer heat can be unbearable. After hauling himself to the beach to moult, an old male uses an ingenious technique to get himself back to the cool of the water – a roly-poly!

Summers in the Arctic today bring record-breaking heat. With climate change, it is warming faster than anywhere else on Earth. It is predicted that the Arctic Ocean could become ice-free each summer by 2035, raising new challenges for polar bears. Without sea ice, more and more bears are becoming stranded on remote Arctic islands. It’s a dangerous place to be for a mother bear with cubs, surrounded by larger, predatory males.

03. Frozen Peaks

Mountains create frozen habitats on every continent on Earth, and each of these high-altitude worlds holds unique challenges for its surprising and remarkable life.

We begin our journey close to the equator – the furthest point from the poles – in East Africa. Here on the high slopes of Mount Kenya, during the day the tropical sun keeps the cold at bay, but at night the frost descends. During this cycle of freeze and thaw, a pregnant high-casqued chameleon must choose the right time to give birth if her newborns are to escape the deadly night freeze.

Away from the equator in the European Alps, long cold winters give way to short, bountiful summers. For a pair of golden eagles raising their chick, the demand to provide enough food for it drives them to tackle prey five times their size. To catch a goat-like chamois, they risk it all using one of the most daring and breathtaking hunting techniques ever witnessed.

The mountains of Japan are the snowiest place on Earth, providing hostile conditions for a lone male macaque cast away from his troop. His only chance of survival comes with finding another male whose embrace will provide him with life-saving warmth. But in the frozen peaks, the deadliest force is an avalanche whose full destructive power is captured for the first time using high-speed camera racer drones.

The roof of the world is home to an array of unexpected cold-loving creatures. In the remote Southern Alps of New Zealand, a species of parrot – the kea – uses its famed intelligence to feed on the dead. And in the Andes in South America, flamingos thrive in high-altitude volcanic lakes, but their chicks must race to escape the winter freeze or risk becoming trapped in the ice.

Today, due to climate change, our frozen peaks are undergoing rapid change. Using groundbreaking time-lapse photography, we reveal mountain glaciers vanishing before our very eyes and discover what a warming world may mean for our most famous mountain resident of all, the giant panda.

04. Frozen South

Antarctica is the most hostile of all earth’s frozen worlds. Yet even here, amongst some of the most challenging conditions on the planet, life finds a way not just to survive, but thrive.

Our journey begins at the far edge of the continent, on its far-flung sub-Antarctic islands. Here we meet king penguins that, to feed at sea, must face the danger of ferocious leopard seals lurking in the shallows. On another island, we witness for the first time male Antipodean wandering albatross partnering up with each other as the females in their population are disappearing due to fishing activity.

Heading towards the continent of Antarctica, we traverse the roughest seas on earth – the Southern Ocean – where we find the rarely filmed Antarctic blue whale, the largest animal to have ever lived. At the edge of Antarctica, the sea is so cold that it freezes over, creating a vital ice platform for a mother Weddell seal to raise her precious pup. Still, she needs to protect him from aggressive males.

In spring, the coast of Antarctica is free of snow, drawing in thousands of breeding chinstrap penguins. Stones are at a premium to build their elevated nests and protect chicks from meltwater. But stealing is commonplace, and to make matters worse, with climate change we find chicks today shivering with hypothermia – a warming Antarctica means increased meltwater. Other residents are facing an uncertain future too, including wave-washing killer whales. We discover that their favourite prey, Weddell seals, are now harder to reach, so instead they are resorting to targeting much more feisty prey, including leopard seals, an apex predator in its own right. This dramatic encounter has never been filmed before.

Travelling into the interior of the continent – into the frozen heart of Antarctica – we find great surprises. This is one of the most volcanic regions on earth, and one of the driest. We reveal unexpected sand dunes, hidden in a rare ice-free valley. Then, on the exposed mountain tops, sticking out from the otherwise ice-covered interior, we find tiny snow petrels, which raise their chicks further south than any other bird, and defend their territory by projectile vomiting!

The greatest revelation lies deep in the interior, beneath the surface of an ice-covered lake, where we discover ancient alien-like structures – giant stromatolites – built by primitive lifeforms. If life can make it here, in the extremes of Antarctica, it raises the possibility that life can exist elsewhere, including in the frozen lakes of distant planets.

05. Frozen Lands

In the far north of our planet lies the largest land habitat on earth, home to snow-covered forests and the icy open tundra. These are lands of extremes that push animals to their limits: in winter they are so cold that much of the ground has remained frozen since the last ice age. To stand any chance of survival, animals must adapt in extreme ways: here a super pack of wolves, 25 strong, has come together to take on the only large prey available to them in winter, American bison.

On the featureless tundra, an Arctic fox must strike a living alone. She is a wanderer and will roam many hundreds of miles searching for tiny lemmings, hidden deep underground. The only way to reach them is with a head dive. In the remote far east of Russia, a rare Amur leopard prowls the seemingly empty, snow-covered forest. With little prey available, it must use its ingenuity to find a meal. It follows crows in the hope of finding carrion, but it must not stay long, for it shares the forest with a far larger but equally hungry big cat, the Siberian tiger.

As spring arrives, the forests begin to thaw and life returns. Beneath the ground, a nest of tiny painted turtle hatchlings now emerge, having remained frozen in a state of suspended animation throughout winter. To the north, it is a further month before the sun’s warmth baths the frozen ground of the tundra. Tucked away underground lies a tiny snow queen – a Lapland bumble bee. She is the sole survivor of her colony – the rest perished in the winter freeze – but her larger size, her furry body and antifreeze in her blood have allowed her to survive. Now she is in a hurry. She must feed herself and raise a brood in the brief window of summer while the flowers are in bloom.

Snowy owls also use the open tundra to breed: one pair have raised a nest full of fluffy chicks. With 24-hour daylight in which to hunt, the dedicated parents bring back meal after meal for their ever-growing brood. But one day, they return to find the nest empty…

Today, the biggest challenge in the tundra is climate change. Warming summers are melting the permafrost deep within the soil, causing the ground to thaw and, in places, the land to collapse. These changes are impacting the animals too. Caribou arrive in herds of 200,000 individuals to raise their calves in the rich pastures, but warming means mosquitos emerge sooner and bother the calves before they have had a chance to gain strength. The parents drive their young to cooler, mosquito-free land, but to get there they must cross rivers running with increased meltwater and escape hungry grizzly bears. They, like much of the tundra’s wildlife, are adapted to live in the extremes – but the challenge of today’s warming climate could be one extreme too many.

06. Our Frozen Planet

Our frozen planet is changing. In this final episode, we meet the scientists and people dedicating their lives to understanding what these changes mean, not just for the animals and people who live there, but for the world as a whole.

Our journey begins in the Arctic, where every summer huge quantities of ice calve from the edges of Greenland’s melting glaciers. On top of the ice cap itself, glaciologist Alun Hubbard descends into a moulin to try to understand the mechanisms that are driving this historic loss of ice.

Elsewhere in the Arctic, it’s not just land ice that is disappearing. In the Gulf of St Lawrence, Canada, biologists are trying to find out how the loss of sea ice will impact the lives of baby harps. In Arctic Russia, with the loss of summer sea ice, more and more polar bears are arriving on the island of Wrangel. Here, a local ranger and scientists are braving the hungry bears to assess their future survival.

Loss of sea ice impacts not just wildlife but people too. In the remote community of Qaanaaq, Greenland, local Inuit hunters are finding the ice too dangerous to travel and hunt on, risking their traditional way of life. And these changes happening in the Arctic have the potential to affect people far beyond. On Alaska’s open tundra, bubbling lakes hint at the gases being released from the previously frozen soil, including the potent greenhouse gas methane.

There is one place where the full scale of a melting Arctic can be best witnessed – from space. Based in the International Space Station, astronaut Jessica Meir looks down at forest fires across Europe and reflects how our changing weather patterns are interconnected.

Rapid ice loss is also happening across the high mountains of the planet’s continents. Glaciologist Hamish Pritchard uses a sophisticated helicopter-strung radar system to try to quantify how much ice is left in the previously uncharted glaciers of the Himalayas. It’s important as, downstream, some 1.2 billion people rely on glacial meltwater as their primary source of fresh water.

Finally, in Antarctica, we meet Bill Fraser, who has dedicated 45 years of his life to studying the Adelie penguin. Over this period, he has witnessed changes in weather conditions and the extinction of entire colonies. These ‘canaries in the coal mine’ are a sign that all is not well, even in the remotest place on earth. And changes here have the potential to affect all of us, so an international group of scientists is on an urgent mission to assess the stability of a huge body of ice known as the Thwaites ice shelf. If this plug of ice melts and slips into the ocean, it will raise global sea levels, impacting coastal communities across the planet.

The unprecedented changes our scientists are witnessing may be profound, but there is hope that, through a combination of technology and willpower, there is still time to save what remains of our frozen planet.

SIMILAR TITLES:

Frozen PlanetBlue Planet 2Seven Worlds, One PlanetThe Blue PlanetNature’s Great EventsPlanet Earth

BBC One - Frozen Planet II

How Earth's breathtaking frozen wildernesses are changing before our eyes.

^BBC