Jude 1 NIV
14 Enoch, the seventh from Adam, prophesied about them: “See, the Lord is coming with thousands upon thousands of his holy ones 15 to judge everyone, and to convict all of them of all the ungodly acts they have committed in their ungodliness, and of all the defiant words ungodly sinners have spoken against him.

Gen 5:22-29
Enoch "walked with God: and he was no more; for God took him"

That book is mentioned in the Bible and Enoch was definitely a prophet. Don't confuse the angels with the giants, 2 different things and yes, aliens=demons. Do not be deceived by the Great Deceiver.