“There is the sky, which is all men’s together.” Euripides
Four Billion years from now our once lone galaxy will have a major collision with the oncoming Andromeda Galaxy. The collision will result in a merger of the two galaxies remaking the two into a larger galactic body. The remake of our two revolving nests of stars will not damage our own fragile arrangement of planetary bodies but will fling our star into a new region of this now larger galaxy.
As NASA notes: “Computer simulations derived from Hubble’s data show that it will take an additional two billion years after the encounter for the interacting galaxies to completely merge under the tug of gravity and reshape into a single elliptical galaxy similar to the kind commonly seen in the local universe. Although the galaxies will plough into each other, stars inside each galaxy are so far apart that they will not collide with other stars during the encounter. However, the stars will be thrown into different orbits around the new galactic center. Simulations show that our solar system will probably be tossed much farther from the galactic core than it is today.”
The insight to the collision “came through painstaking NASA Hubble Space Telescope measurements of the motion of Andromeda, which also is known as M31. The galaxy is now 2.5 million light-years away, but it is inexorably falling toward the Milky Way under the mutual pull of gravity between the two galaxies and the invisible dark matter that surrounds them both.”
The conclusion of the intersection and merger after the initial collision will take an additional two billion years to complete and will happen under a massive pull of gravity between the two systems. The resultant reshaped form will be a single elliptical galaxy similar to a type commonly seen in our proximate local universe. Though the Milky Way (our place of residence) and Andromeda will crash into one another, stars which compose each galaxy are placed so far from one another that the probability of collisions are minimal. “After the merger most of the stars will be thrown into entirely new places around the new galactic center. Simulations show that our solar system will probably be tossed much farther from the galactic core than it is today.”
See the Hubble/NASA site.