Debris. Debris everywhere. I’d guess that the main mental characteristic driving flat earthers and moon landing deniers is that they’re neat nuts. The idea that space is filled with random crapola of various sizes and compositions must be worse that trying to fall asleep without checking to see if their shoes are touching.
Aristotle proclaimed that stones don’t fall from the sky, and that ridiculous bias held up until a meteorite came down and struck in the presence of some king or something, just a few centuries ago.