Milky Way Heading for Catastrophic Collision

The Whirlpool Galaxy (M51a) and companion galaxy (M51b). This Hubble Space Telescope image represents a merger between two galaxies similar in mass to the Milky Way and the Large Magellanic Cloud. (Image: NASA, ESA, S. Beckwith (STScI), and The Hubble Heritage Team (STScI/AURA))