Alien Engineering (Part 1 of 2): What would happen if a UFO actually did land on Earth and humans found it? Engineers create a 'spaceship' to see how alien technology could work. (S1, ep 1)
Some experts claim that UFO wreckage is stored in a top-secret facility in Dayton, Ohio. Former employees spin a tale of alien bodies and flying saucer debris. (S1, ep 10)
Beyond The War Of The Worlds: HG Wells' classic tale of a Martian invasion has terrified audiences for more than 100 years. The history of its many retellings is revealed. (S1, ep 11)
Brazil's Roswell: In 1977, a remote Brazilian island was visited nightly by strange flying objects, leaving people with bizarre puncture marks and blood loss. What happened? (S1, ep 12)
Britain's Roswell: In December 1980, Air Force personnel witnessed strange lights hovering above the English countryside. Did they have a close encounter with alien spacecraft? (S1, ep 13)
Mexico's Roswell: In 1974, the US government was tracking a UFO when it disappeared over Coyame, Mexico. At the same time, a civilian plane crashed. Why was it all covered up? (S1, ep 14)
Real UFOs: A look at the secret flying saucers designed by the military around the world. Sightings in the US, South Africa, Russia, Australia and Canada have all given the locals a fright.
Russian Roswell: An exploration of the facts and myths surrounding the Soviet-era UFO research programmes at Kapustin Yar. (S1, ep 16)
Alien Engineering (Part 2 of 2): Laser weapons and tele-transporters would probably all be fitted to an alien spaceship, but what if they could be used by humans too? (S1, ep 2)
Canada's Roswell: On 4 October 1967, dozens of eyewitnesses reported seeing what appeared to be a UFO hovering above the water's surface in Nova Scotia. Was it an alien ship? (S1, ep 3)
Sightings of the 70s: Accounts from a number of UFO sightings that took place in the 1970s, including the most famous of all intergalactic crashes: Roswell.
China's Roswell: In 1938, hundreds of mysterious stone disks were found in a cave in China. Some believe the stones are proof of contact with an alien race. Fact or fiction? (S1, ep 5)
The Grey's Agenda: Alien abductees undergo hypnotic regression to see if there is any truth in their stories. (S1, ep 6)
Alien Encounters: An examination of what ufology calls "trace cases", where physical material from an encounter is analysed to determine if it is evidence of an alien contact. (S1, ep 7)
Cattle Mutilations: The bloodless murder of livestock has plagued farmlands worldwide for generations. Are extraterrestrial beings responsible? (S1, ep 8)
Texas' Roswell: In April 1897, an unidentified craft crashed in Aurora, Texas. Locals claimed they buried the spaceship and its alien pilot. Can a new search uncover the remains? (S1, ep 9)