The word Anunnaki means "princely seed" or "princely blood". The idea is that the Anunnaki were direct creations of Anu, who was regarded as the father and king of the gods. Ancient Aliens: "In the ancient texts of Sumeria we have descriptions of these being descending from the sky called the Anunnaki. The term Anunnaki means 'those who from the heavens came."

For the animals in the polar regions, autumn means dramatic battles and epic journeys. Time is running out - the Arctic Ocean is freezing over and the sea ice is advancing at 2.5 miles per day around Antarctica. Polar bears gather in large numbers on the Arctic coast as they wait for the return of the ice. Soon, tempers fray and violent sparring contests break out. Meanwhile 2,000 beluga whales head for one special estuary, a gigantic 'whale spa' where they will thrash their snow-white bodies against the gravel and exfoliate. Inland, the tundra undergoes a dramatic transformation from green to fiery red. Here, musk ox males slam head-first into each other with the force of a 30mph car crash as they struggle to defend their harems. Frisky young caribou males play a game of 'grandma's footsteps' as they try to steal the boss's female. Down in Antarctica, Adelie penguin chicks huddle together in creches. When a parent returns from fishing, it leads its twins on a comical steeplechase - sadly there's only enough for one, so the winner gets the meal. Two months later and the chicks are fully feathered apart from downy Mohican hairdos - they're ready to take their first swim - reluctantly though, as it seems penguins are not born with a love of water! And with good reason - a leopard seal explodes from the sea and pulls one from an ice floe, a hunting manoeuvre that has never been filmed before. As winter approaches and everyone has left, the giant emperor penguin arrives and makes an epic trek inland to breed. The mothers soon return to the sea leaving the fathers to hold the eggs and endure the coldest winter on earth.

A young common chimpanzee nicknamed Oscar is part of a close-knit tribe of chimpanzees. They occupy a forest territory which is rich in native fruits, nuts, and figs, among other things. The chimps hunt small tree monkeys, and they also eat termites collected with primitive tools made from sticks. They also use rocks as tools to crack nuts. Oscar is tended by his mother, nicknamed Isha, and from her he begins learning many things about how to survive in the jungle. In the chaos of an attempted raid by a rival gang of chimpanzees led by 'Scar', Isha is injured and separated from the group and her son. This twist of fate leaves Oscar to fend for himself with a little help from an unexpected ally.

Rivers provide the essentials of life: fresh food and water. They often provide natural highways and enable us to live in just about every environment on Earth. But rivers can also flood, freeze or disappear altogether!Cities - Surviving the Urban Jungle Human Planet joins Sam Niang, a Laotian fisherman, as he walks a high wire strung above the raging Mekong River rapids on an extraordinary commute to work. There's also a look at the remarkable partnership between Samburu tribesmen and wild elephants in their search for water in the dried-out river beds of Northern Kenya. Plus, a father who must take his two children on a six-day trek down a frozen river - the most dangerous school run on Earth, and the ice dam busters of Ottowa with their dynamite solution to a city centre hold-up.

This episode of the documentary series focuses on the new giants, the heavyweights of the dinosaur world. It is only in recent years that experts have unearthed the biggest dinosaurs that ever lived. One monster eclipsed all others; more than seven times as heavy as diplodocus was the immense argentinosaurus - a single backbone was bigger than a human. For years, these giants were considered immune to attack from any predator - until the discovery of mapusaurus, a new giant killer whose fate appeared to be inextricably linked to argentinosaurus

brilliant mathematicians whose genius has profoundly affected us, but which tragically drove them insane and eventually led to them all committing suicide. Kurt Gödel, the introverted confidant of Einstein, proved that there would always be problems which were outside human logic. His life ended in a sanatorium where he starved himself to death. Finally, Alan Turing, the great Bletchley Park code breaker, father of computer science and homosexual, died trying to prove that some things are fundamentally unprovable.