im just wondering if there is any clue on how long a Xeno can actually live being active. To my knowlege(which is mostly restricted to the movies) it hasn't been said. We've seen them live for very long periods of time, but only though cryogenics. Though, i dont exactly know if you could count the eggs in the Space Jocky ship or not, since it seemed pretty icy, though the egg opened up without to much trouble. and on there it had to have been a long while because the Jocky with the hole in his chest seemed to have been decomposing for quite a while.