The great flood in the Okavango turns 4,000 square miles of arid plains into a beautiful wetland. Elephant mothers guide their families on an epic trek across the harsh Kalahari Desert towards it, siphoning fresh water from stagnant pools and facing hungry lions. Hippos battle for territory, as the magical water draws in thousands of buffalo and birds, and vast clouds of dragonflies. Will the young elephant calves survive to reach this grassland paradise? The experienced mother elephants time their arrival at the delta to coincide with the lush grass produced by the great flood.
In a TV first, the programme shows the way they use their trunks to siphon clean water from the surface layers of a stagnant pool, while avoiding stirring up the muddy sediment on the bottom with their feet. Lechwe swamp deer, zebras, giraffes, crocodiles and numerous fish and thousands of birds arrive in the delta. And, in a phenomenon never before filmed in the Okavango, thousands of dragonflies appear - seemingly from nowhere - within minutes of the flood arrival, mating and laying eggs. As the flood finally reaches its peak, elephants and buffalo, near the end of their epic trek across the desert, face the final gauntlet of a hungry pride of lions. In a heart-wrenching sequence, a baby elephant is brought down by a lion in broad daylight.

Dan Snow uncovers the lost Vikings in America with space archaeologist Dr Sarah Parcak. Sarah uses satellites 383 miles above the earth to spot ruins as small as 30cm buried beneath the surface. As Sarah searches for Viking sites from Britain to America, Dan explores how they voyaged thousands of miles when most ships never left the shoreline. He also tracks their expansion west, first as raiders and then as settlers and traders throughout Britain and beyond to Iceland and Greenland. In North America they excavate what could be the most westerly Viking settlement ever discovered.

Take an exhilarating, unprecedented exploration of the seven most amazing wonders of our solar system. Our virtual tour begins with a trip to Enceladus, one of Saturn's outer moons, where icy geysers spout from its surface. Then venture to Saturn's famous rings, which contain mountain ranges that rival the Alps. Next dive into the eye of the biggest storm in the solar system--Jupiter's Great Red Spot. Soar through the Asteroid Belt, containing millions of leftover rocks from the formation of the solar system. Trek up Mount Olympus, the largest volcano, located on Mars. Have a close encounter with the searing surface of the Sun, and finish the journey by exploring our home planet Earth.

A featured documentary that explores the rise of a new Internet. Decentralized, encrypted, dangerous and beyond the law. The Deep Web, also called the Deep Net, Invisible Web, or Hidden Web is the part of the World Wide Web not indexed by search engines. The deep web was several orders of magnitude larger than the surface web. The majority of the information is hidden or locked inside databases and is growing exponentially at a rate that cannot be quantified. In 2008, to facilitate users of Tor hidden services in their access and search of a hidden .onion suffix, Aaron Swartz designed Tor2web, a proxy application able to provide access by means of common web browsers. Using this application, deep web links appear as a random string of letters followed by the .onion TLD.

Let's go behind the scenes at NASA to discover how it is preparing for its most ambitious and daring mission: to land men - and possibly women - on the surface of Mars. It's over 40 years since Neil Armstrong made the first human footprint on the moon. But getting to the red planet would involve a journey of at least three years. Meet the scientists and engineers who are designing new rockets, new space suits and finding ways to help astronauts survive the perils of this long voyage. And it turns out that having the 'right stuff' for a mission to mars might not be quite what you expect.

Our planet has amazing power, and yet that's rarely mentioned in our history books. This series tells the story of how the Earth has influenced human history, from the dawn of civilisation to the modern industrial age. It reveals how geology, geography and climate have been a far more powerful influence on the human story than has previously been acknowledged. A combination of epic story telling, visually stunning camerawork, extraordinary locations and passionate presenting combine to form a highly original version of human history" In the first episode professor Iain Stewart explores the relationship between the deep Earth and the development of human civilisation. He visits an extraordinary crystal cave in Mexico, drops down a hole in the Iranian desert and crawls through seven-thousand-year-old tunnels in Israel. His exploration reveals that throughout history, our ancestors were strangely drawn to fault lines, areas which connect the surface with the deep interior of the planet. These fault lines gave access to important resources, but also brought with them great danger.