It's amazing what tricks that swamp gas, migrating geese, and the planet Venus can do. < /sarcasm>
An oldie but goodie: in the late 70s I remember reading
UFOs, the Eye and the Camera, by Adrian Vance. They are interdimensional beings. It is most likely out of print, but might be worth trying to find a copy.
Anything is possible. Sort of like the "religion of peace".