Alright, so for this case... seems like there's another world which can interact with out world through the sky of this specific area. And the other world is kinda like the afterlife or something similar, where the head researcher dude was actually someone who died years ago, and came back to this world to "observe" or something. When he met his daughter who was the one actually still alive, he vanished. But apparently that was enough to let the "other side" know that it's possible for them to interact and stay in our world, which causes the invasion of falling people at the end.
So I guess the questions are, is the other world the actual afterlife? Why did the father's corpse only appear at the end, when he was apparently fine until he met his still living daughter? What did the initial fallen body at the beginning of the chapter have to do with anything, especially the note that he died 60 years ago? What about the researcher who looked at the sky and then apparently walked up into it, what happened with him?