Unidentified objects, witnessed by military pilots... Extraterrestrial probes, flying through our solar system... And a potential alien home world that may be hidden - in the darkness of space. Does the recent string of strange encounters and phenomena get us closer to answering the age old questions, are we alone in the universe? What tools are we using to hunt for signs of life in outer space? And is it possible that evidence of alien intelligence has actually reached planet Earth

The blue marble we call Earth remains in large part a mystery to the 8 billion people who live on it. How did Earth come to exist, and what are the secrets of its survival? How long will humans be able to call it "home"?