The series, depicted by state of the art CGI techniques, and applying the laws of life on Earth to the rest of the galaxy, blends fact with science fiction and conceptualizes what alien life might be like on other planets.
In the prologue, astronomer Didier Queloz makes an appearance to discuss the discoveries of exoplanets and how they are analyzed in the real world. In Episode 1, the fictional world imagined is Atlas, a world with higher gravity than Earth and a thicker atmosphere leading to airborne creatures. In explaining the aliens of Atlas, the episode also explores the handicap principle in insects, and shows a rehabilitative form of falconry as captive falcons are trained to live in the wild.

NASA's brand-new Mars rover is on the hunt for alien life, and with the help of cutting-edge engineering, scientists embark on a search for fossilized remains, which might prove the Red Planet was once home to a vast ocean and extraterrestrial life. Perseverance carries seven scientific instruments to study the Martian surface at Jezero crater. It carries several cameras and two microphones. The rover is accompanied by the helicopter Ingenuity, which will help Perseverance to scout for locations to study.

James Cameron journeys to some of the Earth's deepest, most extreme and unknown environments in search of the strange and alien creatures that live there. Joining him is a team of young NASA scientists and marine biologists who consider how these life forms represent life we may one day find in outer space not only on distant planets orbiting distant stars, but also within our own solar system.
Aliens of the Deep is the result of expeditions to several hydrothermal vent sites in the Atlantic and the Pacific. These are violent volcanic regions where new planet is literally being born and where the interaction between ocean and molten rock creates plumes of super-heated, chemically-charged water that serve as oases for animals unlike anything ever discovered. Six-foot tall worms with blood-red plumes and no stomach, blind white crabs, and a biomass of shrimp capable of 'seeing' heat all compete to find just the right location in the flow of the super-heated, life-giving water or to fry.

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.

The hunt for aliens is on! After a distinguished career in cosmology Professor Martin Rees, the astronomer royal, has taken up the search for extra-terrestrials. Looking for aliens is no longer science fiction - it is a question that's engaging some of the greatest minds in science." As our knowledge of the universe has increased, we're getting closer to answers. Many scientists now think we live in galaxy with a billion Earth-like planets, many of which may be teeming with life. But what kind of life? Has anything evolved into beings we could communicate with? This film gets inside the minds of the scientists considering one of the most exciting and profound questions we can ask - are we alone in the universe? Professor Rees thinks we may have our idea of what an alien is like all wrong. If he's right, it's not organic extra-terrestrials we should look for, it's machines.