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- Coma Cluster on Wikipedia
Coma Cluster
Details
The Coma Cluster is one of the richest and most famous galaxy clusters in the nearby universe. Its galaxies move as if embedded in far more mass than we can see directly, making Coma one of the classic systems that helped reveal the existence of dark matter.
The Coma Cluster is one of the classic great gatherings of galaxies in the nearby universe, but its real importance comes from more than crowded abundance. Coma became famous because its galaxies move as though they are embedded in far more mass than the visible stars alone can account for. That made it one of the earliest and clearest places where the universe hinted that much of its mass is hidden.
What makes Coma so enduring is that it joined observation and theory in a very direct way. A rich cluster full of galaxies, hot gas, and enormous gravitational binding could not be explained by what astronomers could simply count in starlight. Coma forced the question of missing mass into the open, long before dark matter became a standard part of cosmology.
That is why the Coma Cluster matters as more than a giant city of galaxies. It is one of the historic reference cases that changed how astronomers think about mass on cosmic scales. Coma reminds us that some of the most important discoveries begin not with a spectacular new object, but with an old object behaving too strangely to fit the visible evidence.
7.43million ly
Key facts
- Category
- Galaxy clusters
- Object class
- Galaxy cluster
- Host
- Coma Supercluster
- Scale fact
- 20 million lydiameter
- Composition
- ~1,000 galaxies, hot intracluster gas, dark matter
Scale context
Where Coma Cluster sits on the full axis
By size on the journey, Coma Cluster sits between Virgo Cluster and Virgo Supercluster. The band below compares Coma Cluster with nearby Galaxy cluster objects so the size jump stays easy to read.
Shared physical scale
13.0million ly
Together, these objects make the size change around Coma Cluster easy to compare at a glance.
Between the smallest and the largest, perspective is everything.
About
Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.
Guides turn parts of that scale into curated essays, while focused views let you explore the same range through specific groups of objects.