circumgalactic medium

Galaxies Breathe Gas, and When They Stop, No More Stars Form

For most of the history of astronomy, all we could see were stars. We could see them individually, in clusters,…

7 months ago

Hubble Shows the True Size of Andromeda

It's possible that you've seen the Andromeda galaxy (M31) without even realizing it. The massive spiral galaxy appears as a…

4 years ago