I doubt that. Any advanced civilization that is capable of interstellar travel would use highly efficient techniques to do their thing. You may say it's the gol

I doubt that. Any advanced civilization that is capable of interstellar travel would use highly efficient techniques to do their thing. You may say it's the gold or platinum but we just heard of the neutron stars that collided creating a lot of those materials in the process. Why bother using humans to extract anything when there are other, more efficient, ways of harvesting? That's just "ancient aliens" conspiracy theories if you ask me.