Documentary AreaSimply the best Documentaries

The Milky Way, our galaxy, is a magnificent sight in the night sky, but we know surprisingly little about it for certain. What is its shape? How many stars does it actually contain? What lies at its centre? The Gaia space telescope will answer these questions, being armed with the most advanced camera to leave our planet, and it will allow us to see our galaxy as we've never seen it before. The Sky at Night visits the factory in Chelmsford that made the astonishing sensor at the heart of the mission.

From unexplained flashes in the night sky to flying saucers, this episode delves into the mysterious world of UFOs. How our drive to explain these bizarre phenomena, and desire to discover little green men, has in fact transformed our understanding of the universe

New planets are now being discovered outside our solar system on a regular basis, and these strange new worlds are forcing scientists to rewrite the history of our own solar system. Far from a simple story of stable orbits, the creation of our solar system is a tale of hellfire, chaos and planetary pinball. It's a miracle our Earth is here at all.

Evolution tells us that all life exists for only one purpose: to reproduce. But is that all there is? How could such a simple imperative lead us to create great art and civilizations? A new theory suggests that instead of passing on genes, our ultimate purpose is to process and pass on information. We are the universe figuring itself out. Scientists dig deep into DNA, chemistry, technology and engineering to find the meaning of life. One thing is certain: living is easier if you find a reason for living.

Our universe seems real. But what if it’s a videogame? Scientists in a variety of fields are taking seriously the possibility that we live in a virtual reality. Maybe the Big Bang was just the moment someone flipped the switch and turned on our universe. Maybe what looks random has already been programmed to happen. If some advanced civilization did design and program our universe, would we ever know? Scientists are looking for glitches in the laws of the universe that may uncover its hidden code.

We move around in space, but we are stuck in a prison of time moving ever forwards. Einstein said, 'The distinction between past, present and future is only a stubbornly persistent illusion.' Is our experience of the ticking clock merely a trick of the mind? Could science ever make the clock move backwards? Experiments in quantum physics are showing that the future influences the present: what happens later limits the choices we think we have now. The laws of physics say visiting or talking to ourselves in the past is possible – but changing history once we get there is not.