Forget E.T. It’s time to meet the intraterrestrials.
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They too are alien, appearing in bizarre forms and eluding scientists’ search efforts. But instead of residing out in space, these aliens inhabit a dark subterranean realm, munching and cycling energy deep inside the Earth.
Most intraterrestrials live beneath the bottom of the ocean, in an unseen biosphere that is a melting pot of odd organisms, a sort of Deep Space Nine for microbes. Many make their homes in the tens of meters of mud just beneath the seafloor. Others slither deeper, along fractures into solid rock hundreds of meters down.