What will the Apocalypse look like?

Scientists continue to tell us that the Sun will eventually run out of hydrogen, which feeds it. Once this point is reached, the Sun will die. However, before that happens, it will begin to expand until, eventually, it destroys everything left on Earth. It's really interesting to think about how the Apocalypse will happen. Will it be 5 billion years from now, or will people have settled in other galaxies by then? Perhaps the Apocalypse is much closer than many might think. Perhaps people will cause any apocalyptic events or asteroids will contribute to this?