- For information on the Earth of the Re-imagined Series, see Earth (RDM).
- For information on the Earth of Galactica 1980, see Earth (1980).
The lost Thirteenth Tribe settles on the planet Earth, its settlers having departed long ago from Kobol after the same environmental cataclysm which caused the Exodus of the Twelve Tribes and made Kobol uninhabitable. As stated in the Book of the Word, the Thirteenth Tribe left opposite the other Twelve Tribes, the information of their destination residing in the tomb of the Ninth Lord of Kobol (Lost Planet of the Gods).
Transmissions from Earth -- the Apollo Moon Landing -- are picked up by Apollo in the Celestial chamber on an obsolete gamma frequency, although the copy of the transmission is destroyed in an attack on a Cylon basestar (The Hand of God).
- Due to the discovery of several planets inhabited by humans of the Thirteenth Tribe, especially Terra and the Eastern Alliance, it may be assumed that Earth is very advanced in terms of technology, and could be more than a match for the Cylons.
- These planets may be inhabited by humans left behind by the Thirteenth Tribe on the trek to Earth (if not migrated and forgotten members of other Colonial habitations), and as such give no real clue as to Earth's status. The transmission of the Apollo 11 landing (which, barring other non-Einsteinian means, would travel at light-speed) could be used to define the distance between the Fleet and Earth. However, the events of Galactica 1980 (set 30 years after the events in the Original Series) contradict this.