Asteroids strike, planets collide, black holes blast out death rays, volcanoes erupt and ice engulfs the planet. These are the universe's weapons of extinction. They've happened before - wiping out entire species, and they will happen again. Are we next?

Is Time Travel Possible? Stephen Hawking explores the world's favourite scientific 'what if?' He explores all the possibilities, warping the very fabric of time and space as he goes. From killing your grandfather to riding a black hole, we learn the pitfalls and the prospects for a technology that could quite literally, change everything.

Brian takes a fresh look at the concept of gravity, revealing it to be far more than just the force that makes things fall to the ground.
In the last three years, we've made profound discoveries about the nature of gravity and the way it behaves, and how this relates to the origin of the universe and strange things like black holes. Our theory of gravity has become the attempt to understand the nature of space and time.

Around the world, a new generation of astronomers are hunting for the most mysterious objects in the universe. Young stars, black holes, even other forms of life. They have created a dazzling new set of super-telescopes that promise to rewrite the story of the heavens. This film follows the men and women who are pushing the limits of science and engineering in some of the most extreme environments on earth. But most strikingly of all, no-one really knows what they will find out there.

Today, we know black holes exist, and now scientists are trying to confirm that other holes lurk in hyperspace. Our infinite cosmos could contain a variety of "holes" such as black, white, "mini" and wormholes. White holes are the reverse of black holes; instead of matter being sucked into it, matter is ejected out. Wormholes are gateways in the fabric of space and time. They are included in Einstein's field equations as possibilities for their existence. Neither white holes nor wormholes have ever been found. Learn about new discoveries including, colliding binary black holes, intermediate black holes and manufacturing mini black holes.

Looking back on the major stories of the year - from the New Horizons mission to the most distant world we have ever visited to the release of the first-ever picture of a black hole. The team relive the highlights and uncover the latest developments.