Season 1
Episode: 1x01 | Airdate: Sep 4, 1975
On Moonbase Alpha, the strange deaths of workers is being investigated which leads to the discovery of energy leaks at 2 different sites where Earths atomic waste is being stored. A race ensues to move waste at the second site before a catastrophic event occurs.
Episode: 1x02 | Airdate: Sep 11, 1975
An alien life force invades crewman Anton Zoref, transforming him into a mutated beast that seeks heat at all costs... and his next target is Alpha's nuclear reactor.
Episode: 1x03 | Airdate: Sep 18, 1975
When the Moon heads directly for an alien planet, its queen convinces John to let the collision occur for the sake of her people's evolution and the Moon will be unharmed. Now John needs to convince his own people of the same.
Episode: 1x04 | Airdate: Sep 25, 1975
An alien war fleet declares the Moon an invading virus and launches unrelenting attacks.
Episode: 1x05 | Airdate: Oct 2, 1975
The Moon comes to a frozen planet inhabited by seeming immortals who invites the Alphans to join them.
Episode: 1x06 | Airdate: Oct 9, 1975
Voyager One crosses paths with the Moon, and its creator helps to stop it before its lethal nuclear wake wipes out Alpha. However, an alien fleet from a planet destroyed by the waste comes looking for the probe and its creator seeking revenge.
Episode: 1x07 | Airdate: Oct 16, 1975
The first child born on Alpha ages five years in a matter of days, and then an alien fleet arrives to make the Moon its own.
Episode: 1x08 | Airdate: Oct 23, 1975
Tony Cellini, the only survivor of a deep-space probe, claims that an alien creature consumed his other three crewmen… and now Moonbase Alpha is approaching the same graveyard of alien spaceships.
Episode: 1x09 | Airdate: Oct 30, 1975
The Moon crosses paths with a Darian generational ship. One half of the population lives in savagery, and the other half are sworn to preserve their race no matter what.
Episode: 1x10 | Airdate: Nov 6, 1975
The Moon is attracted by the gravitational force of a black sun, and there appears to be no escape for all but six crew.
Episode: 1x11 | Airdate: Nov 13, 1975
The Moon approaches Piri, where the Guardian offers them an idyllic life if they abandon their home and join it. Only John realizes that Piri is a trap from which they may neve escape.
Episode: 1x12 | Airdate: Nov 20, 1975
The aliens find a psychopathic immortal alien banished by his own people, who plans to begin his "experiments" anew on his rescuers.
Episode: 1x13 | Airdate: Nov 27, 1975
An Eagle returns from a promising new planet with a strange passenger: Leo Russell, Helen's husband who died five years ago and warns the Alphans not to land on the planet.
Episode: 1x14 | Airdate: Dec 4, 1975
An alien spaceship heading to Earth crashes on the Moon, and as the inhabitants make repairs they offer to take one Alphan with them. But at what cost?
Episode: 1x15 | Airdate: Dec 11, 1975
John, Helen, and a landing party explore a primitive planet and going missing. Another landing party find them... living among the savages on the planet, and evolutionary regressed to similar state.
Episode: 1x16 | Airdate: Dec 18, 1975
The Alphas travel to their own future when they return to Earth.. and discover that it's a wasteland with a duplicate Moon orbiting it.
Episode: 1x17 | Airdate: Jan 1, 1976
The Moon gains a breathable atmosphere and the Alphans prepare to settle their home's surface. However, John suspects the aliens who provided the atmosphere.
Episode: 1x18 | Airdate: Jan 8, 1976
Moonbase Alpha is attacked by a sentient war machine, Gwent, that demands that they keep its elderly creator contained within it alive.
Episode: 1x19 | Airdate: Jan 15, 1976
An alien spacecraft attempts to procure Alpha's computer data by "possessing" a crewman. When he dies, the aliens possess Helen to do the same thing.
Episode: 1x20 | Airdate: Jan 22, 1976
An alien scientist and his daughter capture the "primitive" John, believing him to be the missing link in their evolution.
Episode: 1x21 | Airdate: Jan 29, 1976
The Moon plummets into an energy field that is evolving into a vast living brain... and sends antibodies to destroy the "invader" before it is wiped out.
Episode: 1x22 | Airdate: Feb 5, 1976
Biologist Dan Mateo manifests a bizarre murderous spirit while trying to communicate with with his plants: a spirit that kills anyone in its path.
Episode: 1x23 | Airdate: Feb 12, 1976
The Moon is brought to a halt near a planet wiped out by nuclear war.
Episode: 1x24 | Airdate: Feb 19, 1976
Moonbase Alpha finds itself caught up in a war between two planets.
Season 2
Episode: 2x01 | Airdate: Sep 4, 1976
Episode: 2x02 | Airdate: Sep 11, 1976
Episode: 2x03 | Airdate: Sep 18, 1976
Episode: 2x04 | Airdate: Sep 25, 1976
Episode: 2x05 | Airdate: Oct 2, 1976
Episode: 2x06 | Airdate: Oct 9, 1976
Episode: 2x07 | Airdate: Oct 16, 1976
Episode: 2x08 | Airdate: Oct 23, 1976
Episode: 2x09 | Airdate: Oct 28, 1976
Episode: 2x10 | Airdate: Nov 4, 1976
Episode: 2x11 | Airdate: Nov 11, 1976
Episode: 2x12 | Airdate: Nov 20, 1976
Episode: 2x13 | Airdate: Nov 25, 1976
Episode: 2x14 | Airdate: Dec 2, 1976
Episode: 2x15 | Airdate: Dec 9, 1976
Episode: 2x16 | Airdate: Dec 16, 1976
Episode: 2x17 | Airdate: Dec 23, 1976
Episode: 2x18 | Airdate: Aug 4, 1977
Episode: 2x19 | Airdate: Aug 11, 1977
Episode: 2x20 | Airdate: Aug 18, 1977
Episode: 2x21 | Airdate: Aug 25, 1977
Episode: 2x22 | Airdate: Sep 1, 1977
Episode: 2x23 | Airdate: Oct 29, 1977
Episode: 2x24 | Airdate: Nov 12, 1977