For years, astronomers have observed the strange motion of Andromeda, the Milky Way’s closest large galactic neighbor. While ...

For more than a century, astronomers have watched in astonishment as the Andromeda galaxy ignored the grand flow of cosmic expansion and hurtled straight toward the Milky Way. While almost every other ...

For years, astronomers have predicted a dramatic fate for our galaxy: a head-on collision with Andromeda, our nearest large galactic neighbor. This merger—expected in about 5 billion years—has become ...