Milky Way sure to smash into Andromeda — in 4 billion years
It’ll not happen anytime soon, but the Milky way is set to crash into our neighboring galaxy, andromeda. On the large scale, everything is moving away from everything else as the universe expands. But sometimes gravity wins the battle against expansion. In about 4 billion years the milky way and andromeda will collide. Stars are far apart so there will not be any head on star collisions -imagine a few grains of sands moving past each other. But the pull of gravity will likely throw our Sun into a completely different part of the galaxy. These collisions play a big role in the probability do finding life elsewhere in the universe, as we know life takes a long time to develop and these sort of unstable events could kill off early life. No need to worry about this collision though. In 4 billion years our Sun will have used up all its fuel and will have started puffing up into a giant star destroying any remnant life on Earth anyway.