A family portrait of the Andromeda galaxy and its orbiting dwarf satellites raises questions about how galaxies evolve.

In roughly 4 billion years, our home Milky Way galaxy may collide with the neighboring Andromeda galaxy.

The Andromeda galaxy is also known as Messier 31. It is a spiral galaxy located about 2.5 million light-years from Earth. On a clear night, some stars of the galaxy can be seen from Earth.

A new composite image of the Andromeda Galaxy is offering an unprecedented view of our closest spiral galactic neighbor.

Located at a distance of 2.5 million light-years, the Andromeda Galaxy is readily visible to the unaided eye on dark, clear nights. Here's where you should look this week.

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.

The Andromeda galaxy grew by merging with another galaxy in a stellar immigration event reflecting a violent event in our galaxy's past, new research suggests.

Though tiny, this newfound satellite galaxy around M31 offers big lessons — and questions — about how galaxies evolve.

The long-proposed Milky Way and Andromeda galactic merger might not be as certain as astronomers previously believed.

The remarkable thing is that the central bright region of the Andromeda Galaxy can—when it's really dark, and you know just where to look—be glimpsed with the naked eye.

New data show a 50% chance the Milky Way won't collide with Andromeda. A merger with the Large Magellanic Cloud is far more likely.

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.