When galaxies collide

If Homo sapiens can stick it out on Earth for another two billion years, our descendants may witness quite a show in the night sky. Researchers estimate that the Milky Way will collide with its nearest neighbor, the Andromeda galaxy, at around that time—well before the sun collapses into a white dwarf, perhaps destroying the Earth in the process.

That'll be fun, I hope I live long enough to see that.