Space: 1999

Devil's Planet (2x22)

: 01, 1977

Koenig explores a planet that was devastated by some sort of weapon that killed all the inhabitants but did not affect the plants or destroy any buildings. He discovers that there is life on one of the moons and when he goes to investigate, he crash lands, and realizes that the moon is a prison and the inmates don't know they have no one to go home to.