In case you do not know, Book of Enoch is a very controversial book of the Bible, back in the day it was a worshiped and sacred book, but later on was removed from the Bible by the church and deemed a bad omen.
The book talks about the story of Enoch, in first person, and the time he died and went to heaven. Well its portrayed kind of different, for example when he goes to heaven, heaven is much portrayed like outer space, where in the book it says Enoch could even see the stars and other planets, and its mentioned he went there with a flaming chariot, where in reality that chariot could resemble some kind of spaceship.
Once Enoch is in ”heaven” or space, he interacts with being, extra-terrestrials, which could mean he was in contact with aliens.
These beings tell Enoch about Genesis of the Giants, and how the ”sky watcher” or the fallen angels, were sent to Earth by God himself fornicated with the human women.