Latest / What If: Science, Theory, and Possibilities
Aliens Living Inside Earth?
Billions of years ago, a planet collided with Earth, possibly creating the Moon and introducing alien life. What remnants of this planet exist today? Could there be advanced humanoid aliens living within Earth's surface in subterranean cities?
Transcript and sources: What If Aliens are Living Inside Earth?
Questions or concerns? Contact us at Underknown
Get our 100 best episodes in one mind-blowing book: The What If 100
Join this channel to get access to perks: Join
Check out our other shows:
How to Survive: Show Link
Your Body on: Show Link
Crazy Creatures: Show Link
Watch more what-if…
The skinny
The skinny isn't ready yet — notes appear once the transcript is processed.