Endless Facts, One Snippet at a Time
Galactic Clusters: Families of Galaxies Bound Together
- Galactic clusters are groups of dozens to thousands of galaxies held together by gravity.
- The Milky Way belongs to the Local Group, a small cluster of over 50 galaxies.
- Giant clusters like the Virgo Cluster contain thousands of galaxies spanning millions of light-years.
- Dark matter makes up most of a cluster’s mass, holding it all together.
- Hot gas between galaxies in clusters glows in X-rays, outshining the galaxies themselves.
- Galaxy clusters often form superclusters—the largest structures in the known universe.
- Collisions between galaxies in clusters can spark bursts of star formation.
- Gravitational lensing by clusters bends light, magnifying distant galaxies behind them.
- Studying clusters helps astronomers understand dark matter and cosmic structure.
- Clusters are the “cities” of the universe—where galaxies gather, grow, and evolve.