OK two things:
Firstly, that first recording is clearly the Earth breathing. I guess Mother Nature really is a Thing! :P
Second, how frigging awesome is it, that all of those sci-fi shows from our youth, somehow managed to produce sound effects which ACTUALLY sound exactly like these recordings. Art imitating Life? Huh! more like Life imitating Art!
Nice work to all those boffins and Sound Effects Folks. Enjoy one of These ->