This is the full study of this guy:
www.youtube.com/watch?v=skSTzkmOeQw
I have some doubts regarding things he says in there, but there are other facts that he uncovers and explanations that are thought provoking.
I hope those things going on are just advanced military stuff that are tremendously hidden and advanced to current technology that some scientist were able to come up with 30 years go. Otherwise, if they are actually Nephilims pretending to be ETs I can see many Christians faith being shaken. I don't think many Christians are prepared for the latter.