BBC Earth

Learning why an important urban center is sinking toward oblivion; soaring over sprawling ruins buried under Saharan sands; learning the modern secret of an ancient fortress; eyeing a ghost town on the edge of the Gobi.

The sudden release of built-up magnetic energy in the solar atmosphere -- a solar storm -- affects Earth.

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

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

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

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

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

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

Winter bears down on Alaskans, who make last-minute preparations for the return of the freeze.

Africa is home to the greatest collection of wildlife on Earth, with a vast tropical rainforest full of life at its heart, but animals face big challenges in this land of plenty.

From Sydney to the Greater Blue Mountains, Zach and Darin meet with leading eco-warriors to learn about protected lands and habitat conservation.

Levison Wood sets out to walk the length of the River Nile from source to sea; his nine-month, seven-million-step journey takes him through jungles, savannah, deserts, cities and war zones in some of Africa's most remote and spectacular locations.

Lev and his guide Boston are 1100 miles and four months into their journey, in the world's newest nation, South Sudan; arriving in the capital, Juba, Lev and Boston are arrested by secret police.

From Sydney to the Greater Blue Mountains, Zach and Darin meet with leading eco-warriors to learn about protected lands and habitat conservation.

Levison Wood sets out to walk the length of the River Nile from source to sea; his nine-month, seven-million-step journey takes him through jungles, savannah, deserts, cities and war zones in some of Africa's most remote and spectacular locations.

Lev and his guide Boston are 1100 miles and four months into their journey, in the world's newest nation, South Sudan; arriving in the capital, Juba, Lev and Boston are arrested by secret police.

Winter bears down on Alaskans, who make last-minute preparations for the return of the freeze.

Ranchers would hire cowpokes to deliver their cattle when it was time to take the animals to market; Brett and Cliff to test their mettle in the unforgiving landscape of the Southwest.

Africa is home to the greatest collection of wildlife on Earth, with a vast tropical rainforest full of life at its heart, but animals face big challenges in this land of plenty.

Winter bears down on Alaskans, who make last-minute preparations for the return of the freeze.

A bird is in trouble, but is it wildlife? Spring patients are ready to return to the wild.

Get petrified by cryptic rock structures normally hidden from view; look inside curious dwellings in the Peruvian Andes; visit a sacred monolith in Wyoming's Black Hills; haunt a Turkish stone village; spot an immovable waterfall in Mexico.

The sudden release of built-up magnetic energy in the solar atmosphere -- a solar storm -- affects Earth.

A bird is in trouble, but is it wildlife? Spring patients are ready to return to the wild.

Get petrified by cryptic rock structures normally hidden from view; look inside curious dwellings in the Peruvian Andes; visit a sacred monolith in Wyoming's Black Hills; haunt a Turkish stone village; spot an immovable waterfall in Mexico.

The sudden release of built-up magnetic energy in the solar atmosphere -- a solar storm -- affects Earth.

Alaskans work to prepare for the upcoming brutal weather; Chip constructs a mobile tent frame.

A journey from the heat of the tropics to the planet's frozen poles; life has spread to almost every part of the ocean, but there are many different worlds within it and each presents unique challenges.

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

Steve takes a special journey to meet pangolins, the most trafficked animals on the planet, and the people who work tirelessly to save them.

The story of Lusotitan, a colossal, long-necked dinosaur, and its quest for love.

Innovative efforts to confront climate change in Australia, Brazil, California and Kenya; with Dr. M. Sanjayan.

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

Steve takes a special journey to meet pangolins, the most trafficked animals on the planet, and the people who work tirelessly to save them.

The story of Lusotitan, a colossal, long-necked dinosaur, and its quest for love.

Innovative efforts to confront climate change in Australia, Brazil, California and Kenya; with Dr. M. Sanjayan.

Alaskans work to prepare for the upcoming brutal weather; Chip constructs a mobile tent frame.

A look at Isaac Newton;a visit to CERN.

A journey from the heat of the tropics to the planet's frozen poles; life has spread to almost every part of the ocean, but there are many different worlds within it and each presents unique challenges.

Alaskans work to prepare for the upcoming brutal weather; Chip constructs a mobile tent frame.

The rehab is abuzz as Hope's open house approaches; a release at the birthplace of hockey goes offside; a deer doesn't want to depart.

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.

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

The rehab is abuzz as Hope's open house approaches; a release at the birthplace of hockey goes offside; a deer doesn't want to depart.

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.

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

In 1989, a ferocious explosion on the sun's surface released a cloud of highly charged particles containing the energy of 20 million nuclear bombs, and this solar superstorm then hit Earth; in Quebec, Canada, the lights suddenly went out.

The space telescope Hipparcos led to a discovery that sent shockwaves throughout the astronomical community: a star appearing to be older than the universe itself.

In 1989, a ferocious explosion on the sun's surface released a cloud of highly charged particles containing the energy of 20 million nuclear bombs, and this solar superstorm then hit Earth; in Quebec, Canada, the lights suddenly went out.

The space telescope Hipparcos led to a discovery that sent shockwaves throughout the astronomical community: a star appearing to be older than the universe itself.

As winter nears, Alaskans' preparations for the freeze begin to fall apart; the Hailstones fear they may have missed their chance to hunt caribou and stockpile meat for the winter.

An epic journey into the unknown, a realm that feels almost like science fiction.

Gordon Buchanan joins Dr. Victor Lukarevsky in Russia to attempt to rehabilitate two pairs of lynx held captive for years.

Humans are changing our planet so rapidly, it's affecting earth's life support systems: our weather, our oceans and the living world.

In some natural wonders people push themselves to the limit, and survival requires skill, ingenuity and bravery.

Gordon Buchanan joins Dr. Victor Lukarevsky in Russia to attempt to rehabilitate two pairs of lynx held captive for years.

Humans are changing our planet so rapidly, it's affecting earth's life support systems: our weather, our oceans and the living world.

In some natural wonders people push themselves to the limit, and survival requires skill, ingenuity and bravery.

As winter nears, Alaskans' preparations for the freeze begin to fall apart; the Hailstones fear they may have missed their chance to hunt caribou and stockpile meat for the winter.

Professor Brian Cox grapples with science's darker side, asking why it often gets such a bad press; Brian wonders if science can go too far.

An epic journey into the unknown, a realm that feels almost like science fiction.

As winter nears, Alaskans' preparations for the freeze begin to fall apart; the Hailstones fear they may have missed their chance to hunt caribou and stockpile meat for the winter.

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.

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.

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

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.

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.

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

An orphaned baby Triceratops must outwit a deadly Tyrannosaurus rex.

A Spinosaurus, the world's largest ever predatory dinosaur, struggles to bring up his babies and lead his young family across one of the deadliest environments on Earth.

Persued by a group of Utahraptors, a gang of armored dinosaurs battle to reach adulthood.

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

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

The story of Lusotitan, a colossal, long-necked dinosaur, and its quest for love.

Alaskans scramble to secure their livelihoods as the freeze begins; Sue Aikens returns to Kavik find a dangerous predator lurking just outside of camp.

The story of Lusotitan, a colossal, long-necked dinosaur, and its quest for love.

At the onset of winter, Alaskans combat threats; a storm batters Kavik as Sue fortifies camp; Ricko searches for elusive wildlife; the Hailstones ice fish; Johnny secures food in the Brooks Range.

It's officially the third-highest snowfall in Manitoba in the last century; commercial fishers are plagued by deep drifts and hidden pockets of slush that can stop them in their tracks; Chris finds out the hard way that traveling alone is a bad idea.

Levison Wood sets out to walk the length of the River Nile from source to sea; his nine-month, seven-million-step journey takes him through jungles, savannah, deserts, cities and war zones in some of Africa's most remote and spectacular locations.

At the onset of winter, Alaskans combat threats; a storm batters Kavik as Sue fortifies camp; Ricko searches for elusive wildlife; the Hailstones ice fish; Johnny secures food in the Brooks Range.

It's officially the third-highest snowfall in Manitoba in the last century; commercial fishers are plagued by deep drifts and hidden pockets of slush that can stop them in their tracks; Chris finds out the hard way that traveling alone is a bad idea.