From Battlestar Wiki, the free, open content Battlestar Galactica encyclopedia and episode guide

地球は新・旧シリーズにおいてthe lost Thirteenth Tribeの故郷である。

In the Original Series

Boomer analyzing a Gamma frequency transmission (credit:Universal Studios/ABC)

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—i.e. the Apollo Moon Landing—were picked up by Captain Apollo in the Celestial chamber on an obsolete Gamma frequency, though the copy of the transmission was destroyed in the attack on the Cylon basestar (TOS: "The Hand of God").

In Galactica 1980

In Galactica 1980, Earth was discovered, but, much to the dismay of Adama and the survivors, the humans on Earth were underdeveloped and would not be able to defend themselves from the Cylons.[1] The short-lived series primarily depicts the central character's adventures on Earth's surface, including its past through a means of time-travel.

In the Re-imagined Series

Earth is the believed destination of the Thirteenth Tribe of Kobol, as attested in the Sacred Scrolls. The Thirteenth Tribe left for Earth nearly 4,000 years prior to the Fall of the Twelve Colonies. The remaining Twelve Tribes leave Kobol to form the Colonies approximately 2,000 years after the Thirteenth Tribe's departure.

A Cause for Hope

Earth is first mentioned by Commander Adama during a speech after the battlestar's funeral services after escaping from Ragnar Anchorage. Adama claims that Earth was a top military secret that can now be revealed (see Miniseries).

In a private conversation with new President Laura Roslin immediately afterward, Adama admits that he has not the slightest idea where Earth may be, if it exists. His true motivation was inspirational; he intended to bolster the morale of the population (especially his beleaguered crew) in the aftermath of the near-annihilation of humanity.

Tangible Faith

While she is initially skeptical, going so far as to rebuke Adama for his dishonesty, Laura Roslin's faith grows perceptibly throughout the events of the first season. This transition is at least partly due to her use of chamalla as an alternative treatment to her terminal breast cancer. These hallucinations are increasingly interpreted as prophetic vision by Roslin, which continue as the Fleet accidentally discovers the legendary homeworld of Kobol (TRS: "Kobol's Last Gleaming, Part I").

Eventually, a religious artifact is recovered which later aids in revealing the general location of Earth (TRS: "Home, Part II").

In the activated Tomb of Athena, the stars of the Twelve Colonies are represented in the twelve Zodiacal constellations, as viewed from Earth, recognized by Roslin as the shapes of the original flags of the Twelve Colonies. The chamber itself was intended by its builders to be a stylized replica of the night sky of the Earth, from which all twelve constellations could be seen. This is corroborated by Kara Thrace, who quotes scripture, saying that Earth was the place where the people of the Thirteenth Tribe could look up into the sky and see their twelve brothers.[2]

Morerover, Lee Adama recognizes the Lagoon Nebula, also represented in the night sky of the mystery chamber. This astronomical object is known to Fleet personnel, since Commander Adama remarks that this celestial body would take some time to reach.

More Clues to Earth

Over a year later, the Fleet discovers a derelict Cylon baseship near the Lion's Head Nebula, a celestial marker revealed by Felix Gaeta to Admiral Adama and President Roslin (TRS: "Torn"). The information is derived from Gaius Baltar's research on the path to Earth. The derelict basestar finds a ancient beacon left by the Thirteenth Tribe. While a Colonial boarding party finds the probe, it also learns that the Humanoid Cylons aboard the basestar are dead or dying, suggesting a deadly pathogen was released by the beacon. In their haste to leave and for the safety of the Fleet, the beacon is abandoned on the basestar, where it is destroyed when the basestar self-destructs (TRS: "A Measure of Salvation")

After the Fleet must gather needed foodstuffs from the algae planet, believed previously uninhabited by humans, Galen Tyrol senses and finds the Temple of Five, an ancient temple built by the Thirteenth Tribe during a stopover on this world, as told in the Sacred Scrolls. Hidden inside the Temple of Five is the Eye of Jupiter an artifact that may provide more clues to the location of Earth. However, a Cylon force arrives with the same intentions on the Eye, leading to a standoff between Adama and the basestar command (TRS: "The Eye of Jupiter")


  • In one of the extras included on the five-disc DVD release of the first season of Battlestar Galactica, Edward James Olmos (the actor portraying Commander Adama) remarks in a very jocular fashion that they will never reach Earth. Mary McDonnell (the actress who plays Laura Roslin) covers his mouth and tries to hush him while laughing. Although loyal fans may question the trustworthiness of this statement, it is known that the creators keep a "Bible" to the show, to which the actors presumably have access.


  1. Many fans of the Original Series feel that the events of "Galactica 1980" are apocryphal, despite the airing of this information, preferring to consider Earth as undiscovered as of the conclusion of the Original Series. Regardless of its popularity, Battlestar Wiki maintains its canonicity for purposes of this encyclopedia.
  2. Some viewers may question how information on Earth's location could be recorded in the Tomb before the Thirteenth Tribe left for Earth. Had the tribes already visited Earth? Did the tribes originate from Earth? For more information on the circular origins of humanity as it pertains to the Re-imagined Series, see the article on the Sacred Scrolls.