The Virgo cluster’s heart is about 70 million light years away from us. The whole cluster contains more than 2,000 galaxies, and has a noticeable gravitational pull on the galaxies surrounding the Milky Way.
The cluster contains not only galaxies filled with stars but also gas so hot it glows in X-rays.
Motions of galaxies in and around clusters indicate that they contain more dark matter than any visible matter we can see.
