- For information on the Earth of the Re-imagined Series, see Earth (RDM).
- For information on the Earth of Galactica 1980, see Earth (1980).
As told in the Book of the Word, the lost Thirteenth Tribe settles the planet Earth, following its exodus from Kobol from an environmental cataclysm that also caused the Exodus of the Twelve Tribes. As the Thirteenth Tribe left opposite the other Twelve Tribes, the information of their destination resided in the tomb of the Ninth Lord of Kobol, but could not be recovered before Lucifer's attack (TOS: "Lost Planet of the Gods").
Transmissions on an obsolete gamma frequency believed to be from Earth—the Apollo Moon Landing—are intercepted and recorded by Apollo in the celestial chamber. Further analysis of the recording proved impossible as the only copy of the transmission is destroyed in an attack on a Cylon basestar (TOS: "The Hand of God").
- Due to the discovery of several planets possibly 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.