Nah, they're meta physical beings from another dimension,
as old as time itself, and mention in a lot of ancient scriptures and religion today

Angels, devil, jinn, whatever you wanna call it.

How I'm sure? because there's thousands of "proof" they exists on Earth
but ZERO proof that they came from the 7th outer layer of our atmosphere
we can detect the smallest object heading towards earth but until now, ZERO.