Death is life's greatest certainty. But that may be about to change. Scientists have discovered an immortal animal that may hold the secret of endless regeneration. They're on the brink of editing our DNA so that we can cure ageing like a disease. Or is dying necessary for the survival of our species?

Humanity is under threat - from storms that seem to get ever fiercer, earthquakes that seem ever more deadly, and killer viruses that are engulfing the globe. Some scientists think it's time for us to fight back. Can we - should we -hack the planet?

Every 17 minutes in America, someone is killed with a gun. Politicians can't seem to stop the violence. But epidemiologists, psychologists and big data crunchers are discovering that gun crime spreads like a virus -and science may be able to stop its spread.

NASA may have just gotten one step closer to the answering the question: are we alone? The Spitzer Telescope has made a groundbreaking discovery of exoplanets that could be similar to our own. And as Kepler also continues its search, our understanding of the universe continues to be redefined.

Is there anyone out there? Astronomers have been pointing their radio telescopes at the skies for decades trying to pick up alien signals, so far without success. But now there's a new way of looking for aliens. Hitch a ride with Dr Graham Philips as he joins astronomers trawling through the galaxy looking for signs of extra-terrestrial intelligence.

Located beneath Russia's Ural Mountains, Orda Cave is legendary among divers for its unique beauty. The cave's waters are clearest in winter, when the land above lies frozen. With temperatures approaching minus 40 degrees, NHK attempts to film the cave for the first time ever using 4K cameras. Scientists give them insight into the cave's origins, enabling the crew to uncover the miraculous story of how the cave was naturally formed 300 million years ago by climate change and a shifting landscape.