The Andromeda Collision: Our Galaxys Ultimate Fate
TL;DR Summary
In 4.5 billion years, the Milky Way will collide with the Andromeda Galaxy. What will happen to Earth?
The Inevitable Crash
The Andromeda Galaxy is currently 2.5 million light-years away, but it is hurtling toward the Milky Way at 110 kilometers per second. In about 4.5 billion years, the two massive spiral galaxies will collide.
A Ghostly Collision
While "collision" sounds violent, the distance between individual stars is so vast that very few, if any, stars will actually hit each other. Instead, the galaxies will pass through one another like ghosts. However, their immense gravitational fields will interact violently, pulling both galaxies out of shape and scattering stars into long, sweeping "tidal tails."
Milkomeda
The two galaxies will eventually swing back together and merge, forming a single, giant elliptical galaxy that astronomers have nicknamed "Milkomeda." During the merger, clouds of gas will compress, triggering a massive burst of new star formation.