Is mankind alone, or are there aliens out there, either waiting to be discovered, or on their way to find Earth? Professor Brian Cox spends this episode asking such questions, and what he discovers may raise a few eyebrows. He begins by exploring the human race's efforts to find neighbours in outer space, including the launch of two golden discs containing a greeting from Earth in the 1970s; they are still travelling and are now the most distant man-made objects from the planet. Brian also meets members of the Search for Extra-Terrestrial Intelligence, who have been monitoring radio signals for 50 years without success, before discussing the ingredients needed to make an intelligent civilisation with astrophysicist Dr Frank Drake.

Graham-Dixon journeys to the country’s scorched centre to explore Spanish art of the 16th and 17th centuries. From the mystical world of El Greco to the tender genius of Velazquez, this was a moment so extraordinary it became known as the Golden Age. But beneath the glittering surface was a dark and savage heart. Travelling from the architectural jewel of Toledo to majestic Madrid, Andrew Graham-Dixon traces the rise and fall of the Spanish Empire, the brutal conquest of the New World, and the religious madness of the Inquisition, to discover how a history so violent could produce some of the most beautiful art ever seen.

In this bird's-eye view of two continents, demoiselle cranes negotiate a dangerous Himalayan pass on their way to India while high-flying bar-headed geese take the fast track five miles above. In Rajasthan, vultures watch hunting tigers hoping for a meal and pigeons visit a temple dedicated solely to sacred rats. Pigeons are also our guide to the greatest gatherings of camels on Earth and learn to dodge buzzards around the battlements of Jodhpur Fort. 9,000 cranes overwinter in the most unlikely of spots - a barbed wire compound in the centre of a desert town. In Australia, rainbow lorikeets drop in on Sydney and patrol Australia's Gold Coast. In the outback, white cockatoos swirl in thousands and budgerigars pass Uluru (Ayers Rock) and gather in the biggest flocks ever recorded. In China, swallows and swifts visit the Great Wall and the Forbidden City of Beijing. In Japan, the country's most revered birds - Japanese cranes are fed fish by appreciative locals and are joined in strange, momentary harmony by hungry red foxes, white-tailed eagles and Steller's eagles. As peace descends, Japanese cranes dance beautifully in the snow.

The Dutch Golden Age saw map-making reach a fever pitch of creative and commercial ambition. This was the era of the first ever Atlases - elaborate, lavish and beautiful. This was the great age of discovery and marked an unprecedented opportunity for mapmakers who sought to record and categorise the newly acquired knowledge of the world. Rising above the many mapmakers in this period was Gerard Mercator, inventor of the Mercator projection, who changed mapmaking forever when he published his collection of world maps in 1598 and coined the term 'Atlas'. The programme looks at some of the largest and most elaborate maps ever produced, from the vast maps on the floor of the Royal Palace in Amsterdam, to the 24 volume atlas covering just the Netherlands, to the largest Atlas in the world, The Klencke Atlas. It was made for Charles II to mark his restoration in 1660. But whilst being one of the British Libraries most important items, it is also one of its most fragile so hardly ever opened. This is a unique opportunity to see inside this enormous and lavish work, and see the world through the eyes of a King.

Helen Czerski ventures beyond the visible spectrum in the final (and best) episode in this vibrant series, showing how electromagnetic radiation is so much broader than the narrow slice of reality we see with our eyes. Before delving into the details of UV, infrared and x-rays, Dr Czerski explores colour subjectivity by trying on a dress that recently divided the internet — to some it appeared blue and black, to others white and gold. It's a perfect fit. It's also a neat analogy of how people can have opposing views but both swear blind that their perspective is correct. The series ends with some amazing imaging techniques that show our bodies in a whole new light.

Author Henry Hitchings explores the lives and works of Britain's radical and pioneering 18th-century novelists who, in just 80 years, established all the literary genres we recognise today. It was a golden age of creativity led by Daniel Defoe, Jonathan Swift, Henry Fielding, Laurence Sterne, Fanny Burney and William Godwin, amongst others. Robinson Crusoe, Gulliver's Travels, Tom Jones and Tristram Shandy are novels that still sparkle with audacity and innovation. On his journey through 18th-century fiction, Hitchings reveals how the novel was more than mere entertainment, it was also a subversive hand-grenade that would change British society for the better. He travels from the homes of Britain's great and good to its lowliest prisons, meeting contemporary writers like Martin Amis, Will Self, Tom McCarthy and Jenny Uglow on the way.