To follow up on this quote, this whole story is fascinating.
New data collected by the Hubble Space Telescope proves, NASA says, that in 4 billion years the Milky Way and Andromeda will collide or pass each other by so closely that the gravitational force each exerts on the other will cause them to slow down to the point of merging. The merger will be completed 6 billion years from now.
“The clear finding is, we are going to merge with Andromeda,” van der Marel said. “In the past, it was just a possibility, but now it is a known fact that this will happen.”
There is a 9% chance that M-33, a satellite galaxy of Andromeda, will hit the Milky Way first in what van der Marel called a “one-two punch,” causing it to become a satellite of the new galaxy that is formed.
When Andromeda gets here, the sun will likely be pushed out much farther into the universe. By that time though, Earth will have become too hot to be inhabited by humans anyway.
Our sun will not be directly hit when the initial collision happens in 4 billion years. But in 6 billion years, when the merger is complete, our sun will die.