Read Vallee—there is a long long history of this stuff—everywhere in the world:
https://www.amazon.com/Passport-Magonia-Folklore-Flying-Saucers/dp/0987422480
Tell me why there weren’t a lot MORE stories before 1947. Now they’re a dime a dozen, but scanty “long” before that. Same goes for Loch Ness Monster, exactly.