The expansion of the Universe, discovered nearly a century ago by Edwin Hubble, shows that galaxies are moving away from us faster the more distant they are. Yet, our nearest neighbor, the ...

Hubble observations reveal a giant, turbulent planet-forming disk that may reshape theories of how planetary systems develop.

Andromeda is also a flattened spiral like the Milky Way, but it's twice as large — 220,000 light-years across versus 105,000 for the Milky Way — and crammed with a trillion suns. Can you even begin to ...

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

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

A vast, flat sheet of dark matter may solve the long-standing mystery of why our neighboring galaxy Andromeda is speeding ...