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.

After Aubameyang departure and a quiet transfer window, Mikel Arteta is feeling the pressure from fans and critics alike. At home, his wife and family reflect on his tough job. On the pitch, the team seek to keep the dream of a European competition alive. Defender Ben White fights for the respect of the fans and another tough game against Liverpool threatens to derail the team's momentum.

The start of a new year brings the January transfer window and Mikel Arteta the chance to rebuild his squad. Arsenal continue their quest for silverware, competing in the FA and Carabao Cup, as well as still fighting for top 4. Meanwhile, questions over Aubameyang's future continue dominating the media and the club must come to a decision about what to do with their former captain.

The meteoric rise of renewable energy has consequences for our electricity supply. While coal and gas fired power stations can generate electricity whenever you need it, renewables are intermittent by nature. So we need a backup plan for when the wind stops or the sun goes down.
All over the world, engineers and scientists are racing to solve one key problem; how to safely and efficiently store electricity at a huge scale but at a low cost. The quest is producing some truly remarkable ideas and this episode details three of them.

The film tells the story of the ill-fated Nazi Land Speed record attempts. This is a story of engineering excellence, Grand Prix racing, Nazi propaganda, celebrity, and an intense rivalry which would leave a speed record unbroken for 79 years and one of Nazi Germany's best racing drivers dead. During the rise of the Third Reich two German car manufacturers were ordered to build the most high performance vehicles the world had ever seen. What followed was a rivalry that would reap Grand Prix victories, international domination that was a propaganda coup, and provide world fame to its drivers who risked their lives smashing speed records that would stand for 79 years. All under the direct orders of the Fuhrer himself.
Bugatti and Alfa Romeo dominated racing before 1934. But the years from 1934 to 1939 were six tumultuous years in which Grand Prix racing was dominated by the German Auto Union, the arranged marriage of Audi, Horch, Wanderer, and DKW, and Mercedes-Benz teams and provided a spectacle of speed, sound and fury never previously attained and never since matched. There are few periods of racing that have excited as much interest, event attendance and sophistication of equipment as the era of the Silver Cars. They were so far ahead of their time that many of their accomplishments were not duplicated until Mercedes went racing again in the early 1950s. There is also something about men who faced the challenges of staying in a cockpit of a highly sophisticated machine capable of 200 mph with no safety systems. They were giants and among them were Italian Tazio Nuvolari and two greatest German pilots of the thirties, Rudolf Caracciola of Mercedes and Auto Union's Bernd Rosemeyer who duelled with faster, more innovative and sleeker machines, developed in wind tunnels.
This special documentary charts the rise of Nazi Germany's dominate 'Silver Arrow' Grand Prix and Speed Record cars of the 1930's. Leading motor racing and World War 2 experts James Holland, Richard Williams, Eberhard Reuss and Chris Routledge tell the story of the Nazi funded Auto Union and Mercedes Benz 'National Racing Cars'. Hitler's Supercars interweaves the rise of the Third Reich with the racing exploits it funded and what propaganda messages these racing cars where sending.

The Moon Landing celebrates the historic 50th anniversary of Apollo 11, in a fresh and distinctive style. This inspiring documentary subverts usual conventions by beginning with the momentous event, exploring the preceding dramatic sixty minutes in granular detail.
Packed with surprising details which reveal a whole new perspective on the story of how humans landed on the moon, this documentary rewinds one hour before Neil Armstrong's famous footstep to reveal a whole untold story, hidden in the forensic moment-by-moment details driven by powerful footage from the time and authentic audio recordings from the capsule and the command module and mission control in Houston. In the last 60 minutes, the Apollo mission could fall apart. Without dazzling on-the-spot ingenuity, a 240,000-mile helpline to Houston, and almost unnatural abilities to remain calm under incredible pressure, the first step onto another world might not happen at all.