Astronomers have long thought that the Milky Way is headed for an inevitable crash with its neighbor, Andromeda. But a new study complicates the story.

Astronomers have believed for decades that the Milky Way is on a collision course with our nearest big neighbor, Andromeda. They seemed all but certain the two galaxies were destined to smash in about 4 to 5 billion years, combining into one colossal galaxy in space .