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They seem to have a strict society focused on work and progress, with no apparent concern for hobbies or personal pursuits. In the Commonwealth, an alien is seen, able to survive in earth's atmosphere, in a cave near their ship's crashed remains. They breathe a similar atmosphere to humans, and (at least those on Mothership Zeta) subsist mainly on a diet of strange alien worms and squid. Aliens have no opposable thumbs, each hand having three long, tentacle-like fingers with large suction cups at each fingertip that allow them to manipulate objects. Their heads are disproportionately large, with round, heavy-lidded, solid black eyeballs with no discernible iris or pupil a thin, toothless mouth with green tongue, and two pairs of small holes where ears and nostrils would be. BiologyĪliens are diminutive, hairless, yellowish-green-skinned humanoids with short, wiry limbs and green blood. Some of the advanced human technologies were created by using the alien technology like the AI project number 59234: Skynet, created in the 2050s who manages the entire Sierra Army Depot, as well as the device blocking telepathic and psychic commands, the allegedly alien psychic nullifier. And the Enclave recovered an alien blaster and some alien power cells in the armory of the mobile base crawler at Adams Air Force Base. Also, before 2277, an alien body of unknown species was discovered in Fort Bannister. By extension, the Capital Wasteland Brotherhood of Steel have a moderate amount of alien power cells kept in the Citadel's armory and the Brotherhood Outcasts also have some alien power cells at Fort Independence.
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The Brotherhood of Steel around 2161 and the Shi around 2241 encountered the bodies of aliens or their spaceships. Even toy manufacturers such as Wilson Automatoys weren't immune to these accusations and the United States government, which was said to keep its alien specimens and technology mostly in Area 51 (like a flying saucer that was later recaptured by aliens but crashed in California, instantly killing the two pilots). Sources suggest that many of the Enclave's more advanced weapons and robotic systems were based on alien technology. But after the mysterious disappearance, or rather abduction, of the USSA space capsule Clarabella 7 and the pilot astronaut Colonel Hartigan during the 1960s Space Race, the existence of aliens became nationally recognized. For the majority of this time, aliens were unknown to humanity and the realm of science fiction. The zetans' interactions with Earth date back centuries before the Great War, but it is unknown if the other species also visited around this time or came later.
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The only known purpose of the zetans is implied to be experimentation and study on human subjects.
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