Think of it as conditions in the subsurface of a planet where you are very far away from a sun, but you still have water, energy, nutrients, which for some of them means food, and a protection.
Uvažujme o tom, jako o podmínkách v podzemí/podloží planety,  kde jste velmi daleko od slunce, ale na které je i tak dostupná voda,  energie, živiny, což pro některé znamená potravu a ochranu.