Judgement day its talking about here. Surely you can believe the stars can fall if God himself comes down to destroy what he made all himself.
considering that stars are millions of times bigger the earth, technically we'd fall into one of them. this statement cannot be literally true. i mean, unless you think they're all little lights on a big sphere orbiting the earth.
john probably means something like a meteor shower literally (how they would have described it at the time), and something else entirely symbolically.
™ Version 4.2
