It's a voyage of exploration like no other - to Titan, Saturn's largest moon and thought to resemble our own early Earth. For a small team of British scientists this would be the culmination of a lifetime's endeavour - the flight alone, some 2 billion miles, would take a full seven years. This is the story of the space probe they built, the sacrifices they made and their hopes for the landing. Would their ambitions survive the descent into the unknown on Titan's surface?

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.

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.

This episode explores the nature of the greenhouse effect (discovered by Joseph Fourier and Svante Arrhenius), and the evidence demonstrating the existence of global warming from humanity's influence. Tyson begins by describing the long-term history of the planet Venus; based on readings from the Venera series of probes to the planet, the planet had once had an ocean and an atmosphere, but due to the release of carbon dioxide from volcanic eruptions, the runaway greenhouse effect on Venus caused the surface temperatures to increase and boiled away the oceans. Tyson then notes the delicate nature of the amount of carbon dioxide in the atmosphere can influence Earth's climate due to the greenhouse effect, and that levels of carbon dioxide have been increasing since the start of the 20th century. Evidence has shown this to be from mankind's consumption of oil, coal, and gas instead of from volcanic eruptions due to the isotopic signature of the carbon dioxide. The increase in carbon dioxide has led to an increase in temperatures, in turn leading to positive feedback loops of the melting polar ice caps and dethawing of the permafrost to increase carbon dioxide levels. Tyson then notes that humans have discovered means of harvesting solar power, such as Augustin Mouchot's solar-driven motor in the 19th century, and Frank Shuman's solar-based steam generator in the 1910's. Tyson points out that in both cases, the economics and ease of using cheap coal and oil caused these inventions to be overlooked at the time. Today, solar and wind-power systems would be able to collect enough solar energy from the sun easily. Tyson then compares the motivation for switching to these cleaner forms of energy to the efforts of the Space race and emphasizes that it is not too late for humanity to correct its course.

Academy Award-winning director Alex Gibney (Taxi to the Dark Side) masterfully explores the fall of the disgraced cycling champion following the 2009 Tour de France, making use of his extraordinary access to attain rare interviews with former teammates, alleged doping mastermind Dr. Michele Ferrari, and Armstrong himself. What was Lance Armstrong thinking? For years, after seizing international fame as the cancer survivor who won seven Tour de France titles, he fiercely denied accusations that he used performance-enhancing drugs. He used his power to aggressively litigate journalists and publicly humiliate former friends who claimed otherwise. His deceit finally cracked in January 2013, when he admitted guilt to Oprah Winfrey in a television interview that critics decried for only scratching the surface. Academy Award-winning director Alex Gibney approaches Armstrong with unique and extraordinary access. In 2009, Gibney was commissioned to make a film about Armstrong's return to the Tour de France, four years after the racing champion had declared retirement. That race would later stir up devastating evidence in the case against Armstrong. But Gibney came away from the experience unable to reconcile the discrepancy between doping allegations and Armstrong's emphatic denials. Then, post-Oprah, Gibney went back to Armstrong for new interviews to extract a more detailed account of his double life. In The Armstrong Lie, Gibney masterfully explores the complexities of the case, interweaving the dramatic action of the 2009 Tour de France, when Armstrong found himself unexpectedly competing against his own teammate Alberto Contador. Gibney attains rare interviews with Armstrong's former teammates and alleged doping mastermind Dr. Michele Ferrari. The film also raises troubling questions about the process of doping regulation. Recently, when asked to give advice to documentary filmmakers, Gibney responded with a motto exemplified by this film: "Embrace contradictions."

Join the Mars rovers Spirit and Opportunity for an awe-inspiring journey to the surface of the mysterious red planet. Through the eyes of these two intrepid, death-defying rovers, and with NASA scientists and engineers at your side, you’ll see Mars in a way no one ever has before. You’ll feel what it is like to stand on the startling surface of the planet that’s intrigued mankind for eons. And you’ll uncover its ultimate mystery: Is there life on Mars? Roving Mars – it’s the ride of a lifetime.