A look at the solar system's largest planet, Jupiter; its formation and composition and its mini-solar system of over 60 moons – some of which may have the potential to support extra-terrestrial life.

Silk is the invertebrates' great invention, used in a range of ways from from the protective stalks of lacewing eggs to the amazing hanging threads of New Zealand's 'glow worms'. Spiders, though, have taken silk-spinning to extremes. The common wolf spider has no web, but the female is a gentle parent, encasing her eggs in silk and carrying the precious bundle wherever she goes. The bolas spider uses a ball of sticky silk soaked in a copy of moth pheromone to lure its prey. Millions of communal spiders live and feed together in a vast, towering web - an arachnophobe's nightmare.

Ideas about time and space are explored in the changes that constellations undergo over time, the redshift and blue shift measured in interstellar objects, time dilation in Albert Einstein's theory of relativity, the designs of both Leonardo da Vinci and spacecraft that could travel near light speed, time travel and its hypothetical effects on human history, the origins of the Solar System, the history of life, and the immensity of space. In Cosmos Update, the idea of faster-than-light travel by wormholes (researched by Kip Thorne and shown in Sagan’s novel Contact) is discussed.

Sagan reflects on the future of humanity and the question of 'who speaks for Earth?' when meeting extraterrestrials. He discusses the very different meetings of the Tlingit people and explorer Jean-François de La Perouse with the destruction of the Aztecs by Spanish conquistadors, the looming threat of nuclear warfare, and the threats shown by destruction of the Library of Alexandria and the murder of Hypatia. The episode ends with an overview of the beginning of the universe, the evolution of life, and the accomplishments of humanity and makes a plea to mankind to cherish life and continue its journey in the cosmos. The Cosmos Update notes the preliminary reconnaissance of planets with spacecraft, the fall of the Berlin Wall and the end of apartheid in South Africa, and measures towards the reduction of nuclear weapons.

The BBC's definitive television history of the rise and fall of the Nazis. The Nazis - A Warning From History exposes the popular myths surrounding the rise and fall of the Third Reich. The series explores how the Nazis came to power, how they ruled, how they treated their occupied territories and, above all, how a cultured nation could be responsible for such acts of inhumanity. How could a political party as fundamentally evil and overtly racist as the Nazis come to power? This remains one of the most enigmatic questions of the last century. Acclaimed historian Laurence Rees examines what led a cultured nation at the heart of Europe to commit the atrocities it did. In so doing, he exposes popular myths and encourages understanding of the real forces that led to one of the darkest chapters in modern history. Was it simply the hypnotic power of Hitler's rhetoric? Did the Gestapo really impose themselves by terror on an unwilling population? Through interviews with witnesses and perpetrators, along with archive film and records, this six-part series unveils a more chilling reality.

This episode looks at the battle for Moscow and considers why more civilians died in this war than any other in history.