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. Composed by NASA and international space partners, the image combines data from ...

More The Andromeda galaxy's spiralling stars are played as musical notes in a new NASA observatory video, creating a cosmic crescendo that's out of this world. The sonification video, released by ...

When layered, they depict a vibrant and active galaxy reminiscent of our own—and the information is already helping experts expand on Andromeda’s ongoing life story.

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

A collision between our Milky Way galaxy and the neighboring Andromeda galaxy, long considered inevitable, may be in question, astronomers say.

Astronomers reported Monday that the probability of the Milky Way and Andromeda galaxies colliding is less than previously thought.

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.

The Milky Way and the neighboring Andromeda galaxy are currently hurtling through space toward each other at a speed of about 250,000 miles per hour (400,000 kph), setting up a possible future ...

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

Shockingly Tiny Galaxy Near Andromeda Is Just One-Millionth the Size of the Milky Way The fully formed galaxy is remarkably teeny, raising new questions about how galaxies emerge and evolve.