The Andromeda galaxy's family of satellite galaxies point towards the Milky Way, and nobody knows why.

Most of the universe is slipping away from the Milky Way, carried outward as space itself expands. Yet one giant neighbor is bucking the trend, racing straight at us while almost every other major ...

This image from WISE displays the Andromeda galaxy's older stellar population in blue. The disk of the galaxy shows the aftermath of a collision with another galaxy, clear from the warp in the spiral ...

While two teams have ideas about what happened to yellow supergiant M31-2014-DS1, ultimately, it remains a mystery.

A star in the Andromeda Galaxy has inexplicably vanished, leaving behind a puzzling red light source that is baffling astronomers.

The 2011 Brit Marling sci-fi film Another Earth posited the idea of a mirrored version of Earth entering the Milky Way. The idea seems preposterous, and it probably is–in the film, the “other Earth” ...

Dots show locations of stars in the spectroscopic survey superimposed on an image of the Andromeda galaxy (M31). Dots are color coded according to their velocity relative to the Milky Way, as measured ...

Go into your backyard about 20:30 p.m. EST or thereabouts this weekend and you can see the most incredible thing – the Andromeda Galaxy – one of the farthest objects visible to the naked eye. If you ...

The typical blue spiral galaxy (top) continues to form stars actively until it collides with another galaxy. At that point, an active galactic nucleus (AGN) is formed that depletes the galaxy of dust, ...