Comet ISON can well be the brightest and most spectacular comet for a generation. It appeared above the eastern horizon from December 2013 as a glorious streak across the sky. ISON has been travelling towards the sun for ten thousand years and will make only one orbit through its corona before disappearing off into the outer solar system.
But as well as providing a great spectacle, ISON's tail of vaporised gas and water, hundreds of millions of kilometres long, will give insights into some of the greatest mysteries of science; it will help explain the origins of the solar system, whether earth's water was delivered on comets and even whether we are alone in the universe.

Award winning wildlife photographers Jonathan and Angela Scott have travelled the world, always returning home to Kenya. There they introduced the world to the big cats of the Maasai Mara and now they are part of its fight for survival.

Buddhists, Hindus, and hundreds of thousands of travellers from around the globe flock to Cambodia every year to experience the grandeur of Angkor. Its famous temples were built over the span of five centuries by the rulers of the Khmer Empire, and endure today as one of Earth's greatest archaeological wonders. Join us as we shed light on one of the most enigmatic, mesmerizing civilizations in the history of mankind. We peel away the myth and legend to uncover the hidden story behind the creation of this ancient city.
Angkor Wat is the largest temple on the face of the Earth and is a symbol of one of the greatest empires in the history of Southeast Asia. And yet, for centuries, the sacred structure remained lost within the tropical forests of Cambodia, along with the history of the young king who built the temple. Discover the story of Suryavarman II and how he ushered in the golden age of the Khmer Empire. See how Angkor Wat was constructed over four backbreaking decades, and witness the monument in its true glory and splendour, as it appeared 900 years ago.

Of the Seven Wonders of the Ancient World, the Hanging Garden of Babylon is the most elusive of these constructions of classical antiquity. While traces have been found of the Great Pyramid of Gaza, the Temple of Artemis at Ephesus, the Statue of Zeus at Olympia, the Mausoleum of Halicarnassus, the Colossus of Rhodes and the Lighthouse of Alexandria, centuries of digging have turned up nothing about the lost gardens of Babylon – until now.
Why, in the nearly 3,000 years since the gardens were presumably built, has no archeological evidence ever been found to support their existence? Is the Hanging Garden of Babylon a myth or a mystery to be solved?
Travel with Dr. Stephanie Dalley of Oxford University’s Oriental Institute and author of The Mystery of the Hanging Garden of Babylon, to one of the most dangerous places on earth, as she sets out to answer these questions and prove not only that the gardens did exist, but also identify where they most likely were located, describe what they looked like and explain how they were constructed.

A decade after An Inconvenient Truth brought climate change into the heart of popular culture comes the riveting and rousing follow-up that shows just how close we are to a real energy revolution. Vice President Al Gore continues his tireless fight, traveling around the world training an army of climate champions and influencing international climate policy. Cameras follow him behind the scenes-in moments private and public, funny and poignant-as he pursues the empowering notion that while the stakes have never been higher, the perils of climate change can be overcome with human ingenuity and passion.
Renowned filmmakers Bonni Cohen and Jon Shenk have taken the baton from 2006 Academy Award-winner Davis Guggenheim. What started then as a profound slide show lecture has become a gorgeously cinematic excursion. Our extraordinary former vice president invites us along on an inspirational journey across the globe that delivers the tools to heal our planet. The question is: Will we choose to take the baton?

On the coast, two worlds collide. Coasts are the most dynamic and challenging habitats in the ocean - that brings great rewards but also great danger. The extraordinary animals that live here must find ingenious ways to cope with two very different worlds. This episode is a rollercoaster ride of heart-stopping action and epic drama, peopled with characters from the beautiful to the bizarre. We meet fish that live on dry land and puffins that must travel 60 miles or more for a single meal, and witness a life-and-death struggle in a technicolour rock pool. In a secluded cove in the Galapagos, sea lions feast on 60kg tuna. It should be impossible - tuna are usually far too fast for sea lions to catch. But here the sea lions club together to herd their prey inshore. Once trapped in the shallows, these huge fish are easy pickings. As the tide recedes in Brazil, lightfoot crabs leap from rock to rock, desperately avoiding the water - their lives depend on it. Moray eels launch themselves from rock pools, jaw gaping. Then octopuses, too. Both crawl across dry rock to set their ambush. Elsewhere, the ever-changing tides create rock pools. But these temporary worlds are a battleground. Predatory starfish turn a magical garden into the stuff of nightmares.