On a clear night, the Milky Way and the Andromeda galaxy look like close neighbors. In space, they really are.

For nearly a century, astronomers have known that the universe is expanding. Most galaxies are carried outward with the flow ...

Will the Milky Way and Andromeda galaxies collide in several billion years? The odds have changed with a new study using 100,000 supercomputer simulations. Credit: NASA's Goddard Space Flight Center ...

For more than a century, astronomers have watched in astonishment as the Andromeda galaxy ignored the grand flow of cosmic ...

The trajectories of the Milky Way and Andromeda, as well as those of the LMC and M33, in 50 simulations. Circles indicate the final positions of the Milky Way and Andromeda after 10 billion years, or ...

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

The distance between the Milky Way and Andromeda in 50 simulations. Just slightly more than half of orbits result in a Milky Way - Andromeda collision within 10 billion years. Sharp features in ...