In summer 2013, the black hole at the centre of the Milky Way was getting ready to feast. A gas cloud three times the size of our planet strayed within the gravitational reach of our nearest supermassive black hole. Across the globe, telescopes were being trained on the heart of our galaxy, some 27,000 light years from Earth, in the expectation of observing this unique cosmic spectacle. For cosmic detectives across the Earth, it was a unique opportunity. For the first time in the history of science, they hoped to observe in action the awesome spectacle of a feeding supermassive black hole.
Mars One plans one-way missions to Mars; the goal is not simply to explore, but to colonize the red planet. A one-way trip saves billions and eliminates the risk of a return voyage. But can the crew survive in such utter isolation? Some candidates for the mission reflect on this challenge.
Dallas Campbell looks back through almost 50 years of the Horizon archives to chart the scientific breakthroughs that have transformed our understanding of the universe. From Einstein's concept of spacetime to alien planets and extra dimensions, science has revealed a cosmos that is more bizarre and more spectacular than could have ever been imagined. But with every breakthrough, even more intriguing mysteries that lie beyond are found. This great journey of discovery is only just beginning.