This scientific visualization of a computer simulation depicts the inevitable collision between our Milky Way galaxy and the Andromeda galaxy (also known as Messier 31). NASA Hubble Space Telescope observations indicate that the two galaxies, pulled together by their mutual gravity, will crash together in a near-head-on collision about 4 billion years from now. The thin disk shapes of these spiral galaxies are strongly distorted and irrevocably transformed by the encounter. Around 6 billion years from now, the two galaxies will merge to form a single elliptical galaxy.
The visualization covers 8.2 billion years into the future at 105 million years per second. Colors are representative: light blue for spiral galaxies (considered "blue" in astronomy parlance because of their active star formation) and orange-yellow for elliptical galaxies (called "red" by astronomers for their old stellar populations). A random background field of galaxies has been added to the simulation in order to indicate the camera motion through the simulation volume.