A deep sea diver is stranded on the seabed with 5 minutes of oxygen and no hope of rescue. With access to amazing archive this is the story of one man's impossible fight for survival.
Chris Lemons were carrying out repairs 100m below the surface of the North Sea, supported by the vessel Bibby Topaz. The vessel's dynamic positioning system failed, causing it to snap the umbilical tether that provided Lemons oxygen, as well as hot water to heat his suit, power for his light, and a radio link to the surface. He was left with only the few minutes of breathable gas contained in the cylinders he wore on his back.
For reasons that are unclear, Lemons survived for around 30 minutes while he was located by a remote underwater vehicle and then by Yuasa, who was able to pull him back onboard the diving bell. The documentary uses genuine footage and audio recorded at the time of the accident on the divers' radios and body cameras, supplemented with interviews of several of the individuals involved, as well as some reconstructed footage, to tell the story of the accident.

Recently, the Event Horizon Telescope project captured the first image ever of a black hole. Now, new discoveries might finally reveal how supermassive black holes are made, and using the latest technology, experts are on the verge of understanding how these monsters grow and how they affect life on our planet.
Supermassive black holes: Gargantuan monsters that lurk at the center of galaxies. Right now you are travelling at half a million miles an hour around a giant black hole four million times the mass of the sun. But there's a mystery about these colossal beasts. We have no idea where they came from. How did they get so big so quickly?

Deep in the mountains of West Virginia, the Green Bank Observatory has been receiving a mysterious signal from deep space. A team of astronomers has been detecting high-energy bursts erupting from unknown sources far off in space since years ago. But one of them is different from the rest. They call it FRB 121102.
What is actually giving rise to this very powerful flash? Could this be a message from an advanced civilization, or is it a much stranger and violent occurrence? Visit the largest steerable radio telescope on the planet for answers.

Ant colonies are one of the wonders of nature - complex, organised and mysterious. This programme reveals the secret, underground world of the ant colony in a way that's never been seen before. At its heart is a massive, full-scale ant nest, specially designed and built to allow cameras to see its inner workings. The nest is a new home for a million-strong colony of leafcutter ants from Trinidad. For a month, entomologist Dr George McGavin and leafcutter expert Professor Adam Hart capture every aspect of the life of the colony, using time-lapse cameras, microscopes, microphones and radio tracking technology.

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.

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.