Earth has endured its fair share of extinctions over the past 4 billion years. They aren't freak accidents, and the culprit is somewhere in space. But do mass extinctions work like clockwork?In Turkey, archaeologists are uncovering evidence a Neolithic, egalitarian utopia. How did it all fall apart?
You'll also see how new technology is giving us fair warning for impending natural disasters, and how pioneering research is granting women diagnosed with cancer new opportunities to become mothers. Plus, we dive into a mustachioed medical mystery, primordial gravity waves and the science of taking risks.