The Hubble Space Telescope has once again taken science fiction and turned it into reality. Considerably more extreme than images of a fading star, new findings have allowed NASA astronomers to predict that the Andromeda Galaxy (otherwise known as M31) is on a collision course with our very own Milky Way Galaxy. Drawn together by their respective gravitational pulls, in addition to surrounding dark matter, the two galaxies are expected to crash into one another in about 4 billion years.
So what could possibly happen when the universe-altering event takes place? According to Gurtina Besla, a Hubble Postdoctoral Fellow at Columbia University, quite a lot:
In the worst-case-scenario simulation, M31 slams into the Milky Way head-on and the stars are all scattered into different orbits. The stellar populations of both galaxies are jostled, and the Milky Way loses its flattened pancake shape with most of the stars on nearly circular orbits. The galaxies' cores merge, and the stars settle into randomized orbits to create an elliptical-shaped galaxy.
With Andromeda still 2.5 million light-years away, a number of other outcomes may result from the crash, but NASA put together the following video which depicts a simulation of one possible collision.