The search for extraterrestrial life is an age-old quest. But recent breakthroughs make today an era like no other in the history of astronomy. From the exhilarating probing of our own solar system and the Kepler mission’s astounding discovery of thousands of extrasolar planets, to the next-generation telescopes under development, the prospects for finding life beyond Earth have never been stronger.
Still, daunting hurdles remain. How can we study anything light years away, let alone a little planet? In the vast universe, where should we even start to look? Is our failure to hear any other voices in the galaxy a sign that we are special? Join leading explorers now searching the galaxy for life and intelligence on other planets—and asks, if we do find other life in the universe... what would that mean?

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.

Are we alone? SETI--the Search for Extraterrestrial Intelligence--is a privately funded project using radio telescopes and optical telescopes to scan the stars for signals.

20 years ago, two astronomers made a remarkable discovery, one which would change the way we view the universe for ever. A planet outside our solar system, orbiting a distant star - an exoplanet. Since then, we have found worlds where it rains diamonds, ones that boil at 3,000 degrees centigrade and even a world with four suns in its sky. But the big question is - will we ever find another Earth? As we close in on the discovery of the 2,000th planet outside our solar system, or exoplanet, we investigates the techniques that are revealing so much about these alien worlds. The documentary asks if we are really any closer to finding another world like our own - a second Earth.

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.

For decades some have suspected that there might be others out there, intelligent beings capable of communicating with us, even visiting our world. It might sound like science fiction, but today scientists from across the globe are scouring the universe for signals from extraterrestrials. Horizon obtained exclusive access to film researchers at the Green Bank Telescope searching for radio signals from Tabby's Star, a star so mysterious that some scientists believe it might be surrounded by a Dyson Sphere, a vast energy collector built by advanced aliens.