Our home galaxy the Milky Way and Andromeda galaxy are on a collision course! The Andromeda is the most distant object one can see with naked eye. Code named M31 or Messier 31, Andromeda is a giant spiral galaxy of about 300 billion stars. This galaxy is about twice as big as the Milky Way and about 2.5 million light years away from us.
The galaxy is moving towards to our own Milky Way at a speed about 500,000 km/hour. Scientists believe, in 3 billion years the two galaxies could collide or merge into each other, generating a spectacle unmatched in our corner of the universe.
Astronomers can simulate the event on supercomputers and compare the results to observations of actual merging galaxies. View a super computer simuation here. Colliding Galaxies Create Active Galactic Nuclei!