More than 2,000 years ago, the thriving city of Petra rose up in the bone-dry desert of what is now Jordan. An oasis of culture and abundance, the city was built by wealthy merchants whose camel caravans transported incense and spices from the Arabian Gulf. They carved spectacular temple-tombs into its soaring cliffs, raised a monumental Great Temple at its heart, and devised an ingenious system that channeled water to vineyards, bathhouses, fountains, and pools. But following a catastrophic earthquake and a slump in its desert trade routes, Petra's unique culture faded and was lost to most of the world for nearly a thousand years. Now, in a daring experiment, an archaeologist and sculptors team up to carve an iconic temple-tomb to find out how the ancient people of Petra built their city of stone. Meanwhile, scientists using remote sensors and hydraulic flumes uncover the vast city and its sophisticated water system. The race is on to discover how these nomads created this oasis of culture in one of the harshest climates on Earth.

In a far cry from the steamy jungles of Rwanda or the icy waters of the Arctic, British naturalist Sir David Attenborough has donned a necktie and met with US president Barack Obama to discuss climate change and the future of the planet. The two met at the White House — a place the naturalist had never yet explored — on Sir David's 89th birthday in May to film the interview". It was the first time the respected wildlife filmmaker had met an American president and he seemed a little awed by the experience. Mr Obama, who grew up watching Sir David's programs, seemed equally thrilled. The president has the environment and climate change on his radar and is anxious to see progress made as his presidency comes to a close. He faces stiff opposition from Republicans in Congress on his plans to tackle climate change, but remains determined to make changes before leaving office. "I don't have much patience for anyone who denies that this challenge is real," he said. "We don't have time for a meeting of the Flat Earth Society." Sir David, who has been called "the godfather of natural history TV" by the BBC, brought to the meeting six decades dedicated to sharing the wonders of the natural world with television audiences. After initially being rejected for television because his teeth were deemed "too big", Sir David went on to make his Life on Earth television series, which has been watched by more than 500 million people worldwide. His name is now synonymous with nature, conservation and wildlife. During the television interview, the men discussed global warming, renewable energy and how children and young people hold the key to reversing the damage.

In August 2014, ISIS militants raided a Yazidi village in Syria, kidnapping thousands of men, women and children. Hundreds of the kidnapped men were killed or forced to convert to Islam; the women and children were sold as sex slaves or to marry ISIS fighters. Many were raped or became victims of other forms of sexual violence. Escaping ISIS depicts 34 of those captured by militants last year — mostly women and young children — reuniting with their families as they escape to freedom". Some victims were brought to freedom through underground networks, guides inside ISIS and resistance fighters. Women contacted the resistance fighters, begging for rescue; some said the alternative is committing suicide. Many escapees walk for several days with little food and water, often barefoot, risking getting recaptured and killed. One resistance fighter was shot in the back of the head in ISIS territory after they found out that he was working against them. The documentary shows parts of this treacherous journey to freedom.

Explore the latest science behind the headlines and the coolest scientific developments that impact our lives. Technology catapults to new heights in 2015, going faster and further than ever before. We have canvassed the world in search of the best and most fascinating science and tech stories of the year for 2015 YEAR IN SCI-TECH". This action-packed hour of fun and intrigue revisits the world’s first glimpse of Pluto and images of water on Mars while exploring what this all could mean for intelligent life in the universe – all while earthling’s inch closer to becoming actual space tourists. Throughout the hour, we revisit the year’s most amazing techological feats and scientific discoveries, including new and elusive animal species discovered deep under the ocean, as well as the hottest tech trends – from hover boards to driverless cars and trucks, and the newest advances in mind-blowing virtual reality.

In this episode, Helen seeks out the colours that turned planet Earth multicoloured. To investigate the essence of sunlight Helen travels to California to visit the largest solar telescope in the world. She discovers how the most vivid blue is formed from sulfur atoms deep within the Earth's crust and why the presence of red ochre is a key sign of life. In gold, she discovers why this most precious of metals shouldn't even exist on the surface of the planet and in white, Helen travels to one of the hottest places on Earth to explore the role salt and water played in shaping planet Earth.

In the high-stakes game of big-wall climbing, the Shark’s Fin on Mount Meru may be the ultimate prize. Sitting at the headwaters of the sacred Ganges River in Northern India, the Shark’s Fin has seen more failed attempts by elite climbing teams over the past 30 years than any other ascent in the Himalayas. To undertake Meru, says Jon Krakauer, the bestselling author of Into Thin Air, "You can’t just be a good ice climber. You can’t just be good at altitude. You can’t just be a good rock climber. It’s defeated so many good climbers and maybe will defeat everybody for all time. Meru isn’t Everest. On Everest you can hire Sherpas to take most of the risks. This is a whole different kind of climbing."