Fancisco Pizarro hoped to find great riches in the land of the Inca when he set off on his third voyage to the new world in 1527. Travel back in time with Michael Wood and learn how Pizarro ransomed the life of a king for a room full of gold and silver. Trough letter and drawings from the 16th century and film from modern-day south America, discover this remarkable story of greed, faith, dishonor and valor.

Hernan Cortes left Cuba in 1519 seeking riches in the island to the west. Instead he discovered, and ultimately destroyed, a hitherto unknown civilization. Join Micheal Wood as he retraces this fateful expedition. Read Spanish eyewitness accounts that describe the conquistadors' awe at the Aztec achievements and the lust for native treasure. Learn the Aztec' side of the story by scrolling trough pictographs that tell of the agonizing fall of the empire.

Professor Brian Cox seeks to understand the nature of time and its role in creating both the universe and ourselves. From an extraordinary calendar built into the landscape of Peru to the beaches of Costa Rica, Brian explores the cycles of time which define our experience of life on Earth. But even the most epic cycles of life can't begin to compare to the vast expanse of cosmic time. Ultimately, Brian discovers that time is not characterised by repetition but by irreversible change. The vast universe is subject to these same laws of change. As we look out to the cosmos, we can see the story of its evolution unfold, from the death of the first stars to the birth of the youngest. This journey from birth to death will ultimately lead to the destruction not just of our planet, but also the entire universe, and with it the end of time itself. Yet without this inevitable destruction, the universe would be without what is perhaps the greatest wonder of all; the brief moment in time in which life can exist.

Hundreds of years ago in faraway Iceland the Vikings began to write down dozens of stories called sagas - sweeping narratives based on real people and real events. But as Oxford University's Janina Ramirez discovers, these sagas are not just great works of art, they are also priceless historical documents which bring to life the Viking world. Dr Ramirez travels across glaciers and through the lava fields of Iceland to the far north west of the country to find out about one of the most compelling of these stories - the Laxdaela Saga.

Gravity is the most powerful and exacting force in the universe. It is pervasive and penetrating. Gravity binds us together, its reach hangs stars in the sky and its grip crushes light. Gravity holds planets together, and leashes them to their suns. Without gravity, stars, comets, moons, nebulae, and even the Earth itself would not exist. Explore how science and humanity discovered, overcame and utilized gravity. Learn what it takes to propel objects into the heavens, to ride a wave or to ski down a slope. Take a front row seat as an astronaut subjects himself to the weightless wonders of the specially modified aircraft used to train astronauts known as the "Vomit Comet."

In 2014, the International Space Station had to move three times to avoid lethal chunks of space debris and there is an increasing problem of satellites mysteriously breaking down. With first-hand accounts from astronauts and experts, know the scale of the problem of space junk. Our planet is surrounded by hundreds of millions of pieces of junk moving at 17,000 miles per hour. Now the US government is investing a billion dollars to track them, and companies around the world are developing ways to clear up their mess - from robot arms to nets and harpoons. Learn the science behind the hit film Gravity and discovers the reality is far more worrying than the Hollywood fiction.