Many argue that flying saucers and other extra-terrestrial space ships continuously visit the earth. If that were true, what kinds of technologies would such alien spacecraft require? And do eyewitness reports of UFO sightings jibe with modern theories of how interstellar travel might be possible? Authors, astronomers and theoretical physicists weigh in with the blueprints for inertia-canceling devices, nuclear-powered craft, antimatter propulsion systems and even warp drives. Based on Einstein's theories and countless scientific studies, we'll find out how these visitors might bridge the vast distances between the stars. And if they could survive such hazardous journeys, are they flesh and blood or intelligent machines?

Is Time Travel Possible? Stephen Hawking explores the world's favourite scientific 'what if?' He explores all the possibilities, warping the very fabric of time and space as he goes. From killing your grandfather to riding a black hole, we learn the pitfalls and the prospects for a technology that could quite literally, change everything.

Michael Wood tells the tale of China's first great international age under the Tang Dynasty (618-907). From the picturesque old city of Luoyang, he travels along the Silk Road to the bazaars of central Asia and into India on the track of the Chinese monk who brought Buddhism back to China. This tale is still loved by the Chinese today and is brought to life by storytellers, films and shadow puppet plays. Then in the backstreets and markets of Xi'an, Michael meets descendants of the traders from central Asia and Persia who came into China on the Silk Road. He talks to Chinese Muslims in the Great Mosque and across town hears the amazing story of the first reception of Christianity in 635. Moving south, Michael sees the beginnings of China as an economic giant. On the Grand Canal, a lock built in 605 still handles 800 barges every day! The film tracks the rise of the silk industry and the world's favourite drink - tea. Michael looks too at the spread of Chinese script, language and culture across east Asia. 'China's influence on the East was as profound as Rome on the Latin West', he says, 'and still is today'. Finally, the film tells the intense drama of the fall of the Tang. Among the eyewitnesses were China's greatest poets. In a secondary school in a dusty village, where the Chinese Shakespeare - Du Fu - is buried in the grounds, the pupils take Michael through one famous poem about loss and longing as the dynasty falls. And in that ordinary classroom, there is a sense of the amazing drama and the deep-rooted continuities of Chinese culture.

China's last empire, the Qing, lasted from 1644 to 1912. It began in violence and war as the Manchus swept down from the north, but invaders became emperors, with three generations of one family ruling the country. Among them, Michael Wood argues, was China's greatest emperor - Kangxi. Under the Qing, China doubled in size to include Xinjiang in the far west, as well as Mongolia and Tibet, creating the essential shape of China today. The new dynasty tolerated a diversity of cultures and religions, including Islam. In Kaifeng, Michael visits a women's mosque with a female imam, a delightful scene that ends with laughter and selfies! The Qing also undertook huge cultural enterprises. At a traditional printing house where the wood blocks are hand-carved, we see how the Complete Tang Poems were reproduced - all 48,000 of them. We travel through the wintry countryside to a remote village where a hardy audience watch open-air opera in the snow and visit a painter's studio, and 'storytelling' houses in Yangzhou. In the 18th century, China was arguably the greatest economy in the world, and we get a fabulous sense of the rich culture that came with prosperity. But then came the clash with the British, in the first Opium War, when a British expedition destroyed the Qing navy and extracted territory and trading rights. We leave with a glimpse of the future. 'Every dynasty has risen and declined,' says Michael, 'and has needed new life to regenerate, and this time the catalyst was the British.' Among the ports China ceded was an almost uninhabited island, Hong Kong, one of today's greatest financial centres, and Shanghai, a small town then but now one of the greatest cities in world.

Exploring the moon was humankind’s most incredible journey. Now through the magic of 3D, you can take that giant leap for yourself. Presented and narrated by Tom Hanks, Magnificent Desolation: Walking on the Moon will transport you to the lunar surface to walk alongside the 12 extraordinary astronauts who have been there to experience what they saw, heard, felt, thought and did. A romantic, inspirational depiction of the Apollo astronauts travels on the moon peppered by their quotations of their impressions.

The Great Pyramid of Giza's construction is still shrouded in mystery, despite it being the only survivor among the Seven Wonders of the Ancient World. In Building the Great Pyramid, travel back 4,500 years with the BBC as they re-create the circumstances under which it may have been built, as well as the daily life of the population at that time. Expert archaeologists, Egyptologists, and scholars share their latest theories on what may have happened. The film combines dramatic reconstruction, location shooting and state-of-the-art CGI computer effects. Directed and written by Jonathan Stamp.