Planet Earth has been home to humankind for over 200,000 years, but with a population of 7.3 billion and counting and limited resources, this planet might not support us forever. Professor Stephen Hawking thinks the human species will have to populate a new planet within 100 years if it is to survive. With climate change, pollution, deforestation, pandemics and population growth, our own planet is becoming increasingly precarious. In this landmark film Professor Hawking, alongside engineer and radio astronomy expert Professor Danielle George and a former student, Christophe Galfard, join forces to find out if, and how, humans can reach for the stars and relocate to different planets. Travelling the globe, they meet top scientists, technologists and engineers who are working to answer our biggest questions: is there another planet out there that we could call home? How will we travel across the vast distances of space to get there? How will we survive the journey? And how will we set up a new human civilization on an alien world? Travelling the globe, they meet top scientists, technologists and engineers who are working to answer our biggest questions: is there another planet out there that we could call home? How will we travel across the vast distances of space to get there? How will we survive the journey? And how will we set up a new human civilization on an alien world? Taking in the latest advances in astronomy, biology and rocket technology from the Atacama Desert to the wilds of the Arctic, viewers will discover a whole world of cutting edge research. This programme shows that Professor Hawking’s ambition isn’t as fantastical as it sounds - and that science fiction is closer to science fact than we ever thought.

Take a look back at many of the most fascinating science stories of 2017, a year full of stunning advancements in individual fields of study, from astronomy to biology, geology to history – when we piece these discoveries together we see the year in a new light.

The hunt for aliens is on! After a distinguished career in cosmology Professor Martin Rees, the astronomer royal, has taken up the search for extra-terrestrials. Looking for aliens is no longer science fiction - it is a question that's engaging some of the greatest minds in science." As our knowledge of the universe has increased, we're getting closer to answers. Many scientists now think we live in galaxy with a billion Earth-like planets, many of which may be teeming with life. But what kind of life? Has anything evolved into beings we could communicate with? This film gets inside the minds of the scientists considering one of the most exciting and profound questions we can ask - are we alone in the universe? Professor Rees thinks we may have our idea of what an alien is like all wrong. If he's right, it's not organic extra-terrestrials we should look for, it's machines.

Genius lies somewhere in the human mind, bringing mathematical insight, sparking artistic inspiration and enabling some to see what most cannot. Might we augment our biology with technology to unlock the genius inside us all?

Horizon investigates the idea that the best way to lose weight successfully is a personalised approach, diets tailored to our individual biology and psychology. In a groundbreaking experiment, Dr Chris van Tulleken and Tanya Byron join a team of experts to put 75 overweight volunteers on diets designed to tackle the specific reasons why they eat too much. The volunteers are put through a series of tests at a residential clinic to understand how their genes, hormones and psychology influence their eating behaviour. They are then put on the diets the experts believe are best suited to them. Can science succeed where other diets have failed?

Odds are excellent that extraterrestrial life exists. So why haven’t we found aliens out in the galaxy? Are we looking in the wrong places? New research shows we should look closer to home, even inside our bodies. It turns out that a lot of our DNA is from a mysterious, nonhuman source. Theoretically, alien microbial life can make the journey to Earth from distant worlds, and scientists are finding some unearthly microbes in our upper atmosphere. Could it be from outer space? Could we be part alien? It’s even possible alien life is already here as digital life forms, hiding inside our technology.