NASA's research has found that the our Galaxy the Milky Way is going to crash into the Andromeda Galaxy 3.75 Billion + years in the future. Yeah, it's a long way off, but its still kind of creepy to watch their video of what will happen over time when this occurs. You can read their full article here. Though for some reason the video doesn't work on their site, but you can see that below.
|This is what the night sky will look like just before we hit Andromeda . (Credit: NASA; ESA; Z. Levay and R. van der Marel, STScI; T. Hallas; and A. Mellinger)|
"In the worst-case-scenario simulation, M31 slams into the Milky Way head-on and the stars are all scattered into different orbits," said Gurtina Besla of Columbia University in New York, N.Y. "The stellar populations of both galaxies are jostled, and the Milky Way loses its flattened pancake shape with most of the stars on nearly circular orbits. The galaxies' cores merge, and the stars settle into randomized orbits to create an elliptical-shaped galaxy."
This would lead to quite a bit of chaos, imagine a sci-fi future where stars jostle about, they move, and are destroyed, and everyone must move to spaceships to avoid being destroyed along with them. Would we leave planets which couldn't get into ships to their fate or would we save them? Or are we dumb enough to give up technology and so we're the ones who need rescuing?
Or of course you could also imagine the tale of a galaxy similar to ours that is far far away and going through this same thing.