Go with us behind the scenes at CERN to follow one of the most epic and expensive scientific quests of all time: the search for the Higgs particle, believed to give mass to everything in our universe. However, the hunt for Higgs is part of a much grander search for how the universe works. It promises to help answer questions like why we exist and is a vital part of a Grand Unified Theory of nature". At the heart of the pursuit of the elusive particle is the same feature that makes snowflakes beautiful and human faces attractive: the simple and enchanting idea of symmetry. Presenter Jim Al-Khalil

Our strange rock itself can also be lethal. We tend to think of Earth as our life support but it's not there to support us at all. It's a place that's violent, that's beautiful, that's crazy, that's intense. Mother Nature is a serial killer. We wouldn't be here without mass suicide and events so devastating it makes the extinction of the dinosaurs looks like a tea party. There have been 5 mass extinctions on the planet and 99.9 percent of all species that have ever lived are gone.
Explore the story of how life on Earth has evolved, becoming lethal for life to thrive.

We feel it every moment of our lives but for physicists, gravity is the longest running unsolved mystery of the universe. Why do all objects that have mass pull on one another? Cutting-edge theories are proposing unexpected answers: Gravity could be another force in disguise, a thermodynamic mirage, or even, a shadow of a hidden holographic universe. If so, the force that holds us to the surface of the earth, and holds the earth in orbit around the sun, may be a trick of the mind. We feel it, but it may not be real. Is Gravity an Illusion?

The Russian Arctic is one of the world’s most extreme habitats, yet it is a haven for polar bears, lemmings, arctic foxes and walruses. In late August, massive muskoxen bulls gather together to compete for mating dominance. Each bull can weigh 400 kilogram’s and charge at a speed of 40 kilometres an hour; a head-to-head impact can be heard more than a kilometre away

What are the latest discoveries in the deadly world of asteroids? Will a recently returned Japanese spacecraft become the first to bring an asteroid sample back to our planet? What would happen to America's East Coast if the massive asteroid impact that helped form Chesapeake Bay 35 million years ago struck today? And why did President Barack Obama choose an asteroid as the destination for the next great manned mission into space? Learning about these huge space rocks isn't just about science, it's about survival.

Having learned that Vorenus' children are alive, Pullo sets off to find him in Gaul where he is again a serving soldier in Mark Antony's army. He had hoped to arrive before Octavian and Antony's armies meet in battle. Too late however, he is forced to find what is left of Antony's army in the mountains. He finds Vorenus alive and well, if somewhat battle worn, and they set off to find the children.
The victorious Octavian plans his return to Rome. In Western Turkey, Brutus and Cassius amass their own army, now 19 Legions strong.