A race to find the planet's 60 deadliest creatures.

Steve heads to the Mexican island of Cabo Pulmo, where the people have worked tirelessly to bring their surrounding oceans back to life and make it a marine reserve.

A young Albertosaurus, a relative of Tyrannosaurus rex, must earn her place in a deadly hunting pack or face starvation.

Australia was once home to a group of animals known as megafauna, giants who lived here for millions of years; in a blink of time, the megafauna disappeared forever; a team of scientists are reopening this paleolithic cold case.

Alaskans prepare for the winter months; Andy hunts moose; Sue heads to Fairbanks for a foot procedure; the hailstones teach their daughters to ice fish; Glenn repairs his cabin.

Two brilliant physicists, Albert Einstein and Stephen Hawking have each defined humanity's understanding of the universe but their beliefs on how it works do not always align.

Uncovering surprising undersea relationships and connections as sharks befriend fish and whales play with dolphins.

Alaskans prepare for the winter months; Andy hunts moose; Sue heads to Fairbanks for a foot procedure; the hailstones teach their daughters to ice fish; Glenn repairs his cabin.

When a worldwide pandemic cripples the rehab, wildlife emergencies keep coming in: a bobcat that's been shot, and a massive adult seal; Hope's down to a skeleton crew as critical team members go into quarantine.

An enormous fiery vortex in Redding, Calif.; the island nation of Malta loses a natural treasure; a mysterious radioactive hotspot is discovered near Chernobyl; an unknown force lays waste to a mountain forest in Italian Alps.

Iceland is the world's largest volcanic island and new ground is born daily.

When a worldwide pandemic cripples the rehab, wildlife emergencies keep coming in: a bobcat that's been shot, and a massive adult seal; Hope's down to a skeleton crew as critical team members go into quarantine.

An enormous fiery vortex in Redding, Calif.; the island nation of Malta loses a natural treasure; a mysterious radioactive hotspot is discovered near Chernobyl; an unknown force lays waste to a mountain forest in Italian Alps.

Iceland is the world's largest volcanic island and new ground is born daily.

When a worldwide pandemic cripples the rehab, wildlife emergencies keep coming in: a bobcat that's been shot, and a massive adult seal; Hope's down to a skeleton crew as critical team members go into quarantine.

Sue travels 150 miles to investigate squatters on her property; Andy's sled begins to fall apart while he's collecting firewood; Chip and Agnes brave thin ice to harvest whitefish.

Analyze the ways in which cold has shaped the physical world, and learn why the definition of frozen may require an update; meet scientists pushing frigid temps to their absolute limit, driving technological developments such as superconductors.

A race to find the planet's 60 deadliest creatures.

Steve heads to the Mexican island of Cabo Pulmo, where the people have worked tirelessly to bring their surrounding oceans back to life and make it a marine reserve.

A young Albertosaurus, a relative of Tyrannosaurus rex, must earn her place in a deadly hunting pack or face starvation.

Australia was once home to a group of animals known as megafauna, giants who lived here for millions of years; in a blink of time, the megafauna disappeared forever; a team of scientists are reopening this paleolithic cold case.

Sue travels 150 miles to investigate squatters on her property; Andy's sled begins to fall apart while he's collecting firewood; Chip and Agnes brave thin ice to harvest whitefish.

From a baby whale in danger to marine iguanas battling storms, a look at how animals survive when faced with challenges of the ocean.

From the bone-dry deserts of the Atacama, where penguins weave their way through a minefield of snapping sea lions, to the lush cloud forests of the Andes, South America is full of unusual and ingenious wildlife.

Explaining how freshwater is the lifeblood of planet Earth and why animals depend on it for their survival.

Journey from the lava ramparts to its fiery heart, discovering how this place became one of the most important areas of biodiversity in the world.

From the bone-dry deserts of the Atacama, where penguins weave their way through a minefield of snapping sea lions, to the lush cloud forests of the Andes, South America is full of unusual and ingenious wildlife.

Explaining how freshwater is the lifeblood of planet Earth and why animals depend on it for their survival.

Journey from the lava ramparts to its fiery heart, discovering how this place became one of the most important areas of biodiversity in the world.

Sue travels 150 miles to investigate squatters on her property; Andy's sled begins to fall apart while he's collecting firewood; Chip and Agnes brave thin ice to harvest whitefish.

Analyze the ways in which cold has shaped the physical world, and learn why the definition of frozen may require an update; meet scientists pushing frigid temps to their absolute limit, driving technological developments such as superconductors.

From a baby whale in danger to marine iguanas battling storms, a look at how animals survive when faced with challenges of the ocean.

Sue travels 150 miles to investigate squatters on her property; Andy's sled begins to fall apart while he's collecting firewood; Chip and Agnes brave thin ice to harvest whitefish.

Hope scrambles to save the animals when a burglar busts down the door to the rehab, as the spring baby boom brings in a flood of injured and orphaned animals.

A long-forgotten network of Native American earthworks; a baffling battlefield mystery in Belgium; a mysterious blood red lake on a remote Greek island; an eerie pink glow emulating form the middle of the Pacific Ocean.

Iceland's volcanoes generate one third of earth's land-based lava, but the land was sculpted by ice.

Hope scrambles to save the animals when a burglar busts down the door to the rehab, as the spring baby boom brings in a flood of injured and orphaned animals.

A long-forgotten network of Native American earthworks; a baffling battlefield mystery in Belgium; a mysterious blood red lake on a remote Greek island; an eerie pink glow emulating form the middle of the Pacific Ocean.

Iceland's volcanoes generate one third of earth's land-based lava, but the land was sculpted by ice.

Hope scrambles to save the animals when a burglar busts down the door to the rehab, as the spring baby boom brings in a flood of injured and orphaned animals.

Chip builds a freight sled for winter travel; Sue is forced to brave a dangerous road to get home after a blizzard strands her in Fairbanks; Andy and Kate get their sled dogs ready for winter; Glenn tries to harvest meat for the winter.

Helen Czerski reveals how life began when hot met cold, and how every single living creature on Earth depends on temperature for its survival; she witnesses the remarkable surgery that uses temperature to push the human body to the brink of life.

From the bone-dry deserts of the Atacama, where penguins weave their way through a minefield of snapping sea lions, to the lush cloud forests of the Andes, South America is full of unusual and ingenious wildlife.

Explaining how freshwater is the lifeblood of planet Earth and why animals depend on it for their survival.

Journey from the lava ramparts to its fiery heart, discovering how this place became one of the most important areas of biodiversity in the world.

Chip builds a freight sled for winter travel; Sue is forced to brave a dangerous road to get home after a blizzard strands her in Fairbanks; Andy and Kate get their sled dogs ready for winter; Glenn tries to harvest meat for the winter.

A young Albertosaurus, a relative of Tyrannosaurus rex, must earn her place in a deadly hunting pack or face starvation.

Alaskans face long days and uncertain outcomes during trapping season.

Chris starts his season with a massive catch of Tullibee, only to see his happiness cut short; Justin and Mike start in Hecla and hit the motherlode; a critical fish market closes; Richard's close call on the ice.

Levison begins his journey in Afghanistan's remote and inhospitable Wakhan Corridor.

Alaskans face long days and uncertain outcomes during trapping season.

Chris starts his season with a massive catch of Tullibee, only to see his happiness cut short; Justin and Mike start in Hecla and hit the motherlode; a critical fish market closes; Richard's close call on the ice.

Levison begins his journey in Afghanistan's remote and inhospitable Wakhan Corridor.

Chip builds a freight sled for winter travel; Sue is forced to brave a dangerous road to get home after a blizzard strands her in Fairbanks; Andy and Kate get their sled dogs ready for winter; Glenn tries to harvest meat for the winter.

Helen Czerski reveals how life began when hot met cold, and how every single living creature on Earth depends on temperature for its survival; she witnesses the remarkable surgery that uses temperature to push the human body to the brink of life.

Chris starts his season with a massive catch of Tullibee, only to see his happiness cut short; Justin and Mike start in Hecla and hit the motherlode; a critical fish market closes; Richard's close call on the ice.

Chip builds a freight sled for winter travel; Sue is forced to brave a dangerous road to get home after a blizzard strands her in Fairbanks; Andy and Kate get their sled dogs ready for winter; Glenn tries to harvest meat for the winter.

Hope fights to save a family of foxes; the nursery is hit by a mysterious outbreak.

Dive into the historical and natural secrets of the deep; explore an uninhabited concrete island, ocean spirals off the Australian coast, underwater evidence of a violent past and tracks thousands of metres below the sea's surface.

The highest tides in the world are found in the Bay of Fundy on Canada's east coast.

Hope fights to save a family of foxes; the nursery is hit by a mysterious outbreak.

Dive into the historical and natural secrets of the deep; explore an uninhabited concrete island, ocean spirals off the Australian coast, underwater evidence of a violent past and tracks thousands of metres below the sea's surface.

The highest tides in the world are found in the Bay of Fundy on Canada's east coast.

Hope fights to save a family of foxes; the nursery is hit by a mysterious outbreak.

A hundred days without sunlight approach; Glenn needs to retrieve more wood for heat; Andy and Kate rescue a bear cub; the Hailstones gather resources for themselves and their neighbors; Sue has a long list to complete.

Dr. Helen Czerski reveals how the harnessing of heat's power to transform matter has led to some of humanity's greatest achievements, from molten metal that enabled us to make tools to the searing heat of plasmas that offer near unlimited power.

Alaskans face long days and uncertain outcomes during trapping season.

Chris starts his season with a massive catch of Tullibee, only to see his happiness cut short; Justin and Mike start in Hecla and hit the motherlode; a critical fish market closes; Richard's close call on the ice.

Levison begins his journey in Afghanistan's remote and inhospitable Wakhan Corridor.

A hundred days without sunlight approach; Glenn needs to retrieve more wood for heat; Andy and Kate rescue a bear cub; the Hailstones gather resources for themselves and their neighbors; Sue has a long list to complete.

A group of chimps in Senegal is led by an alpha male named Dave.

Many leading scientists believe there's a possibility to soon detect the first evidence of extraterrestrial life.

Professor Brian Cox explores the solar system's frozen worlds; he meets the dwarf planet where mountains of solid ice float across the surface, the black and white moon painted with frost and a world illuminated by a strange form of ice.

The earth is a machine with its moving parts buried deep beyond our sight; revealing what is beneath our feet.

Many leading scientists believe there's a possibility to soon detect the first evidence of extraterrestrial life.

Professor Brian Cox explores the solar system's frozen worlds; he meets the dwarf planet where mountains of solid ice float across the surface, the black and white moon painted with frost and a world illuminated by a strange form of ice.

The earth is a machine with its moving parts buried deep beyond our sight; revealing what is beneath our feet.

A hundred days without sunlight approach; Glenn needs to retrieve more wood for heat; Andy and Kate rescue a bear cub; the Hailstones gather resources for themselves and their neighbors; Sue has a long list to complete.

Dr. Helen Czerski reveals how the harnessing of heat's power to transform matter has led to some of humanity's greatest achievements, from molten metal that enabled us to make tools to the searing heat of plasmas that offer near unlimited power.

A group of chimps in Senegal is led by an alpha male named Dave.

A hundred days without sunlight approach; Glenn needs to retrieve more wood for heat; Andy and Kate rescue a bear cub; the Hailstones gather resources for themselves and their neighbors; Sue has a long list to complete.

A journey along Ireland's longest river, the Shannon, through an emerald green landscape of rolling hills and sparkling waters; how Vikings, monks and kings have all made their mark.

Missions are heading to Jupiter to discover how planets form and to find out if there is life on the planets four largest moons.

Witness animal spectacles from high above the Earth; watch a whirling herd of northern nomads; see undersea behemoths show off in the Pacific shallows; track a U.S. porcine stampede; confront top ocean predators on the Florida coast.

A journey along Ireland's longest river, the Shannon, through an emerald green landscape of rolling hills and sparkling waters; how Vikings, monks and kings have all made their mark.

Iceland is the world's largest volcanic island and new ground is born daily.

An enormous fiery vortex in Redding, Calif.; the island nation of Malta loses a natural treasure; a mysterious radioactive hotspot is discovered near Chernobyl; an unknown force lays waste to a mountain forest in Italian Alps.

A journey along Ireland's longest river, the Shannon, through an emerald green landscape of rolling hills and sparkling waters; how Vikings, monks and kings have all made their mark.

From the bone-dry deserts of the Atacama, where penguins weave their way through a minefield of snapping sea lions, to the lush cloud forests of the Andes, South America is full of unusual and ingenious wildlife.

From dolphins to cuttlefish, ocean animals possess emotions and behavior similar to humans, including the capacity to love, grieve, deceive and invent.

Uncovering surprising undersea relationships and connections as sharks befriend fish and whales play with dolphins.

From a baby whale in danger to marine iguanas battling storms, a look at how animals survive when faced with challenges of the ocean.

A group of chimps in Senegal is led by an alpha male named Dave.

Australia was once home to a group of animals known as megafauna, giants who lived here for millions of years; in a blink of time, the megafauna disappeared forever; a team of scientists are reopening this paleolithic cold case.

Alaskans face long days and uncertain outcomes during trapping season.

Exploring water plants, some of which can count and hunt; some water plants escape from animals by rolling away or creating bubbles.

Wandering in the spaces between and beyond the planets, where countless worlds exist without any light at all; peeking inside hidden realms that stretch halfway to the nearest star and find out what lies outside the reaches of the most powerful telescopes.

Steve gets a first-hand look at what makes Nile crocodiles so deadly and helps a team of scientists relocate a bunch of man-eaters.

Exploring water plants, some of which can count and hunt; some water plants escape from animals by rolling away or creating bubbles.

Wandering in the spaces between and beyond the planets, where countless worlds exist without any light at all; peeking inside hidden realms that stretch halfway to the nearest star and find out what lies outside the reaches of the most powerful telescopes.

Steve gets a first-hand look at what makes Nile crocodiles so deadly and helps a team of scientists relocate a bunch of man-eaters.

Exploring water plants, some of which can count and hunt; some water plants escape from animals by rolling away or creating bubbles.

Many leading scientists believe there's a possibility to soon detect the first evidence of extraterrestrial life.

Professor Brian Cox explores the solar system's frozen worlds; he meets the dwarf planet where mountains of solid ice float across the surface, the black and white moon painted with frost and a world illuminated by a strange form of ice.

The earth is a machine with its moving parts buried deep beyond our sight; revealing what is beneath our feet.

The journey down the attraction-packed Niagara River is filled with adventure and beauty; navigating the fascinating history and engineering of this border river between Canada and the United States, arriving at the world-famous Niagara Falls.

The diamond's rise from gemstone to a cutting-edge material that is set to revolutionize electronics.

Strange aquatic mammals populating a river in Columbia; a ship marooned in a sea of sand along Namibia's notorious Skeleton Coast; a Boeing 727 jetliner hidden in a pine forest; an unusual pattern is discovered in the Nevada desert.

The journey down the attraction-packed Niagara River is filled with adventure and beauty; navigating the fascinating history and engineering of this border river between Canada and the United States, arriving at the world-famous Niagara Falls.

Iceland's volcanoes generate one third of earth's land-based lava, but the land was sculpted by ice.

A long-forgotten network of Native American earthworks; a baffling battlefield mystery in Belgium; a mysterious blood red lake on a remote Greek island; an eerie pink glow emulating form the middle of the Pacific Ocean.

The journey down the attraction-packed Niagara River is filled with adventure and beauty; navigating the fascinating history and engineering of this border river between Canada and the United States, arriving at the world-famous Niagara Falls.

Many leading scientists believe there's a possibility to soon detect the first evidence of extraterrestrial life.

Professor Brian Cox explores the solar system's frozen worlds; he meets the dwarf planet where mountains of solid ice float across the surface, the black and white moon painted with frost and a world illuminated by a strange form of ice.

Levison begins his journey in Afghanistan's remote and inhospitable Wakhan Corridor.

Levison takes in the scenery in northern Pakistan's mountain valleys.

A young Albertosaurus, a relative of Tyrannosaurus rex, must earn her place in a deadly hunting pack or face starvation.

A race to find the planet's 60 deadliest creatures.

Steve heads to the Mexican island of Cabo Pulmo, where the people have worked tirelessly to bring their surrounding oceans back to life and make it a marine reserve.

From the bone-dry deserts of the Atacama, where penguins weave their way through a minefield of snapping sea lions, to the lush cloud forests of the Andes, South America is full of unusual and ingenious wildlife.

Australia was once home to a group of animals known as megafauna, giants who lived here for millions of years; in a blink of time, the megafauna disappeared forever; a team of scientists are reopening this paleolithic cold case.

Professor Brian Cox explores the solar system's frozen worlds; he meets the dwarf planet where mountains of solid ice float across the surface, the black and white moon painted with frost and a world illuminated by a strange form of ice.

Explaining how freshwater is the lifeblood of planet Earth and why animals depend on it for their survival.

Australia was once home to a group of animals known as megafauna, giants who lived here for millions of years; in a blink of time, the megafauna disappeared forever; a team of scientists are reopening this paleolithic cold case.

Professor Brian Cox explores the solar system's frozen worlds; he meets the dwarf planet where mountains of solid ice float across the surface, the black and white moon painted with frost and a world illuminated by a strange form of ice.

Explaining how freshwater is the lifeblood of planet Earth and why animals depend on it for their survival.

Australia was once home to a group of animals known as megafauna, giants who lived here for millions of years; in a blink of time, the megafauna disappeared forever; a team of scientists are reopening this paleolithic cold case.

Sue travels 150 miles to investigate squatters on her property; Andy's sled begins to fall apart while he's collecting firewood; Chip and Agnes brave thin ice to harvest whitefish.

Chip builds a freight sled for winter travel; Sue is forced to brave a dangerous road to get home after a blizzard strands her in Fairbanks; Andy and Kate get their sled dogs ready for winter; Glenn tries to harvest meat for the winter.

A hundred days without sunlight approach; Glenn needs to retrieve more wood for heat; Andy and Kate rescue a bear cub; the Hailstones gather resources for themselves and their neighbors; Sue has a long list to complete.

Twin fawns arrive at the centre; a volunteer searches for orphans in the woods; Hope tends to a tiny owl.

Traipsing along ancient pathways criss-crossing Easter Island; finding gigantic designs carved into Asia's Eastern Steppe; ascending a tall pyramid rising from Antarctica's icy landscape.

Scientists explore whether Earth's estranged twin Venus could be a vision of our planet's future.

Twin fawns arrive at the centre; a volunteer searches for orphans in the woods; Hope tends to a tiny owl.

Traipsing along ancient pathways criss-crossing Easter Island; finding gigantic designs carved into Asia's Eastern Steppe; ascending a tall pyramid rising from Antarctica's icy landscape.

Some of the world's greatest scientists devise scenarios for destroying Earth.

Twin fawns arrive at the centre; a volunteer searches for orphans in the woods; Hope tends to a tiny owl.

Dark winter brings new challenges in sub-zero temperatures; Andy maintains snow-covered trails; Sue fixes her generator; the Hailstones build a new teepee; Erik takes his wife hunting.

With scientists sending space probes to the furthest reaches of the solar system and beyond, the scientific search for alien life has begun; inspired by a childhood love of science fiction, Brian still hopes to hear from ET.

In the remote reaches of Asia's frozen north, creatures must overcome unique challenges, finding exceptional ways to thrive in a hostile world that pushes life to its very limits.

Australia was once home to a group of animals known as megafauna, giants who lived here for millions of years; in a blink of time, the megafauna disappeared forever; a team of scientists are reopening this paleolithic cold case.

Steve gets a first-hand look at what makes Nile crocodiles so deadly and helps a team of scientists relocate a bunch of man-eaters.

Dark winter brings new challenges in sub-zero temperatures; Andy maintains snow-covered trails; Sue fixes her generator; the Hailstones build a new teepee; Erik takes his wife hunting.

A colony of emperor penguins arrive in Atka Bay, after three months at sea, to raise their chicks through the coming winter.

In the aftermath of a devastating bushfire season, Zac and Darin learn about efforts to rehabilitate the wildlife and livestock population.

Levison reunites with his old friend Binod Parya who once saved his life.

Levison resumes his journey in Nepal, visiting a crash site 150 meters down a steep cliff.

In the aftermath of a devastating bushfire season, Zac and Darin learn about efforts to rehabilitate the wildlife and livestock population.

Levison reunites with his old friend Binod Parya who once saved his life.

Levison resumes his journey in Nepal, visiting a crash site 150 meters down a steep cliff.

Dark winter brings new challenges in sub-zero temperatures; Andy maintains snow-covered trails; Sue fixes her generator; the Hailstones build a new teepee; Erik takes his wife hunting.

With scientists sending space probes to the furthest reaches of the solar system and beyond, the scientific search for alien life has begun; inspired by a childhood love of science fiction, Brian still hopes to hear from ET.

A colony of emperor penguins arrive in Atka Bay, after three months at sea, to raise their chicks through the coming winter.

Dark winter brings new challenges in sub-zero temperatures; Andy maintains snow-covered trails; Sue fixes her generator; the Hailstones build a new teepee; Erik takes his wife hunting.

Lynn plays surrogate to baby beavers; Zach is forced to follow a seal along the coastline; a patient returns after a release goes wrong.

Exploring some of the most cavernous places on the planet, including an expansive Siberian crater with no explainable origin, Greenland's bizarre black holes, an ancient forbidden well in the Yemeni desert, and a voluminous void in Antarctica.

Some of the world's greatest scientists devise scenarios for destroying Earth.

Lynn plays surrogate to baby beavers; Zach is forced to follow a seal along the coastline; a patient returns after a release goes wrong.

Exploring some of the most cavernous places on the planet, including an expansive Siberian crater with no explainable origin, Greenland's bizarre black holes, an ancient forbidden well in the Yemeni desert, and a voluminous void in Antarctica.

Some of the world's greatest scientists devise scenarios for destroying Earth.

Lynn plays surrogate to baby beavers; Zach is forced to follow a seal along the coastline; a patient returns after a release goes wrong.

The Hailstones hide emergency supplies along their hunting and trapping routes; Sue's connection with the outside world hangs in the balance; Erik falls while gathering firewood.

Brian takes a fresh look at the astonishing concept of gravity.

In the aftermath of a devastating bushfire season, Zac and Darin learn about efforts to rehabilitate the wildlife and livestock population.

Levison reunites with his old friend Binod Parya who once saved his life.

Levison resumes his journey in Nepal, visiting a crash site 150 meters down a steep cliff.

The Hailstones hide emergency supplies along their hunting and trapping routes; Sue's connection with the outside world hangs in the balance; Erik falls while gathering firewood.

The leader of a once mighty lion pride must now battle for their very survival; a look at whether or not this extraordinary lioness can save her family from disaster.

A race to find the planet's 60 deadliest creatures.

A race to find the planet's 60 deadliest creatures.

The dangerous journey of the Pachyrhinosaurus, where survival is at stake during the annual migration hundreds of miles north.

Australia was once home to a group of animals known as megafauna, giants who lived here for millions of years; in a blink of time, the megafauna disappeared forever; a team of scientists are reopening this paleolithic cold case.

A race to find the planet's 60 deadliest creatures.

A race to find the planet's 60 deadliest creatures.

The dangerous journey of the Pachyrhinosaurus, where survival is at stake during the annual migration hundreds of miles north.

Australia was once home to a group of animals known as megafauna, giants who lived here for millions of years; in a blink of time, the megafauna disappeared forever; a team of scientists are reopening this paleolithic cold case.

The Hailstones hide emergency supplies along their hunting and trapping routes; Sue's connection with the outside world hangs in the balance; Erik falls while gathering firewood.

Brian takes a fresh look at the astonishing concept of gravity.

The leader of a once mighty lion pride must now battle for their very survival; a look at whether or not this extraordinary lioness can save her family from disaster.

The Hailstones hide emergency supplies along their hunting and trapping routes; Sue's connection with the outside world hangs in the balance; Erik falls while gathering firewood.

Jennie and Stephanie try to save a harbour seal pup.

A perfect circle carved around an ancient peak; a scary phenomenon in the Pacific; strange shapes in a Middle Eastern desert; a formation below the ocean's surface.

Along the west coast of Great Britain, the world's longest uninterrupted footpath forges through more than 800 miles of breathtaking scenery; the diverse landscape of the Welsh coast is a geological treasure.

Jennie and Stephanie try to save a harbour seal pup.

A perfect circle carved around an ancient peak; a scary phenomenon in the Pacific; strange shapes in a Middle Eastern desert; a formation below the ocean's surface.

Along the west coast of Great Britain, the world's longest uninterrupted footpath forges through more than 800 miles of breathtaking scenery; the diverse landscape of the Welsh coast is a geological treasure.

Jennie and Stephanie try to save a harbour seal pup.

Chip and Agnes head to Kiwalik River for hunting and fishing; Sue fabricates snowshoes to scout the tundra; Andy fights through frigid temperatures to replenish his resources; Erik and Martha set fur traps.

Brian explores one of the greatest mysteries in physics: time.

A race to find the planet's 60 deadliest creatures.

A race to find the planet's 60 deadliest creatures.

The dangerous journey of the Pachyrhinosaurus, where survival is at stake during the annual migration hundreds of miles north.

Australia was once home to a group of animals known as megafauna, giants who lived here for millions of years; in a blink of time, the megafauna disappeared forever; a team of scientists are reopening this paleolithic cold case.

Chip and Agnes head to Kiwalik River for hunting and fishing; Sue fabricates snowshoes to scout the tundra; Andy fights through frigid temperatures to replenish his resources; Erik and Martha set fur traps.

The leader of a great Painted Wolf family is growing old and her power to keep the peace is waning; a feud with an ambitious daughter threatens to bring the dynasty down.

Asia is the largest and most extreme continent on the planet, stretching from the Arctic Circle to the tropical forests on the Equator.

Exploring forests as hidden worlds where the lives of animals are entwined, including temperate forests home to whistling wild dogs, as well as rainforests where ninja treehoppers fight off assassin bugs.

At the far tip of South America lies a magical realm that seems frozen in time; known as "the end of the world", this is Patagonia.

Asia is the largest and most extreme continent on the planet, stretching from the Arctic Circle to the tropical forests on the Equator.

Exploring forests as hidden worlds where the lives of animals are entwined, including temperate forests home to whistling wild dogs, as well as rainforests where ninja treehoppers fight off assassin bugs.

At the far tip of South America lies a magical realm that seems frozen in time; known as "the end of the world", this is Patagonia.

Chip and Agnes head to Kiwalik River for hunting and fishing; Sue fabricates snowshoes to scout the tundra; Andy fights through frigid temperatures to replenish his resources; Erik and Martha set fur traps.

Brian explores one of the greatest mysteries in physics: time.

The leader of a great Painted Wolf family is growing old and her power to keep the peace is waning; a feud with an ambitious daughter threatens to bring the dynasty down.

Chip and Agnes head to Kiwalik River for hunting and fishing; Sue fabricates snowshoes to scout the tundra; Andy fights through frigid temperatures to replenish his resources; Erik and Martha set fur traps.

When a fawn is found stuck in thick, toxic tar, Hope assembles her entire team to wash and care for it in a desperate bid to save its life.

Decoding the secrets of long-lost human settlements; scrutinizing a mysterious Norwegian mound, a prehistoric stone circle on the banks of the Tagus River, a lost city in the cradle of civilization and bizarre rock shapes.

Ireland is small in size but epic in wonder; surrounded by the Atlantic ocean, Cliffs of Moher to the extraordinary Giant's Causeway, this land has been shaped and reshaped by both the power of water and violent geological forces.

When a fawn is found stuck in thick, toxic tar, Hope assembles her entire team to wash and care for it in a desperate bid to save its life.

Decoding the secrets of long-lost human settlements; scrutinizing a mysterious Norwegian mound, a prehistoric stone circle on the banks of the Tagus River, a lost city in the cradle of civilization and bizarre rock shapes.

Ireland is small in size but epic in wonder; surrounded by the Atlantic ocean, Cliffs of Moher to the extraordinary Giant's Causeway, this land has been shaped and reshaped by both the power of water and violent geological forces.

When a fawn is found stuck in thick, toxic tar, Hope assembles her entire team to wash and care for it in a desperate bid to save its life.

Andy makes snares; Erik and Martha cut into their last moose quarter; Chip and Agnus hunt caribou; Sue clears the plane runway for her snow machine delivery.

Brian questions how far humans will go in their exploration of the cosmos.

Asia is the largest and most extreme continent on the planet, stretching from the Arctic Circle to the tropical forests on the Equator.

Exploring forests as hidden worlds where the lives of animals are entwined, including temperate forests home to whistling wild dogs, as well as rainforests where ninja treehoppers fight off assassin bugs.

At the far tip of South America lies a magical realm that seems frozen in time; known as "the end of the world", this is Patagonia.

Andy makes snares; Erik and Martha cut into their last moose quarter; Chip and Agnus hunt caribou; Sue clears the plane runway for her snow machine delivery.

The dangerous journey of the Pachyrhinosaurus, where survival is at stake during the annual migration hundreds of miles north.

Alaskans must adapt to new obstacles to survive in deep winter.

Frightening ice conditions and poor weather make the early season treacherous; Justin and Mike experience a violent ice-quake that leaves them rattled; Trevor contends with other fishermen setting their nets too close to his.

Levison reunites with his old friend Binod Parya who once saved his life.

Alaskans must adapt to new obstacles to survive in deep winter.

Frightening ice conditions and poor weather make the early season treacherous; Justin and Mike experience a violent ice-quake that leaves them rattled; Trevor contends with other fishermen setting their nets too close to his.

Levison reunites with his old friend Binod Parya who once saved his life.

Andy makes snares; Erik and Martha cut into their last moose quarter; Chip and Agnus hunt caribou; Sue clears the plane runway for her snow machine delivery.

Brian questions how far humans will go in their exploration of the cosmos.

Frightening ice conditions and poor weather make the early season treacherous; Justin and Mike experience a violent ice-quake that leaves them rattled; Trevor contends with other fishermen setting their nets too close to his.

Andy makes snares; Erik and Martha cut into their last moose quarter; Chip and Agnus hunt caribou; Sue clears the plane runway for her snow machine delivery.

Hope realizes she's not prepared to rescue animals from an oil spill, so she heads across the continent to learn from the best before disaster strikes.

Zoom in on some otherworldly sights; spot a giant glacier on the Red Planet, let the milky seas off the coast of Java bathe your vision, ponder a huge hexagon floating above Saturn and take a spin around a doughnut-shaped lake in Saskatchewan.

From the icy peaks of age-old mountain glaciers to the fog-shrouded canopies of Canada's only rainforest, it's the wettest place in North America.

Hope realizes she's not prepared to rescue animals from an oil spill, so she heads across the continent to learn from the best before disaster strikes.

Zoom in on some otherworldly sights; spot a giant glacier on the Red Planet, let the milky seas off the coast of Java bathe your vision, ponder a huge hexagon floating above Saturn and take a spin around a doughnut-shaped lake in Saskatchewan.

From the icy peaks of age-old mountain glaciers to the fog-shrouded canopies of Canada's only rainforest, it's the wettest place in North America.

Hope realizes she's not prepared to rescue animals from an oil spill, so she heads across the continent to learn from the best before disaster strikes.

As winter begins to fade and signs of spring appear, Alaskans must start to store supplies for the upcoming months.

Satellites follow an elephant family struggling through drought; reveals previously unknown emperor penguin colonies from the color of their poo; discovers mysterious ice rings that could put seal pups in danger.

Alaskans must adapt to new obstacles to survive in deep winter.

Frightening ice conditions and poor weather make the early season treacherous; Justin and Mike experience a violent ice-quake that leaves them rattled; Trevor contends with other fishermen setting their nets too close to his.

Levison reunites with his old friend Binod Parya who once saved his life.

As winter begins to fade and signs of spring appear, Alaskans must start to store supplies for the upcoming months.