Four billion years from now, our own Milky Way galaxy is destined for a collision with the neighboring spiral Andromeda galaxy. The Sun will likely be flung into a new region of our galaxy, but our Earth and solar system are in no danger. Andromeda, also known as M31, is now 2.5 million light-years away, but it is inexorably falling toward the Milky Way.

Computer simulations derived from Hubble data show that it will take an additional two billion years or more after the encounter for the interacting galaxies to completely merge under the tug of gravity.They will reshape into elliptical galaxy.