The fact that our galaxy will collide with M31, also known as the Andromeda Galaxy, is no longer a secret to astronomers. What remained a topic for debate was how this collision will occur, and data recently released by the Hubble Space Telescope provide an answer to this riddle.
Scientists established that the two galaxies will collide head-on at first – around 4 billion years from now – and then recoil away from each other, before drawing closer again. The process will repeat itself several times, before the structures merge with each other, 2 billion years later.
After this process is completed, a giant elliptical galaxy will form, which will either be orbited by the Triangulum Galaxy – currently a companion to Andromeda – or will include it. There is currently no way of knowing for certain what will happen to this smaller galaxy.
The elliptical galaxy that will develop following the merger will be quite massive, since the Milky Way is around 100,000 light-years across, and Andromeda around 170,000 light-years in diameter.
Check out the video above to see their titanic collision.