Galaxy clusters are formed by a dense packing of many galaxies, making them the most massive structures in the universe.

Light takes time to travel through space. Because of this, the light we see from distant objects in the night sky represents ...

The galaxy cluster appears hotter and more mature than it should for its young age, challenging what we think we know about ...

An inexplicably hot, fast-growing cluster of galaxies in the early universe has scientists questioning theories of galactic ...

Scientists have detected a surprisingly hot galaxy cluster dating back to the universe’s infancy. The cluster formed far earlier and burned far hotter than current models predict. Researchers believe ...

You'll find this terrific open cluster midway between 5th-magnitude Sigma Cassiopeiae and 6th-magnitude Rho Cas. This group ...

The “Seven Sisters” of the Pleiades are part of a much larger complex that can help reveal our galaxy’s deep history ...

Astronomers found a young galaxy cluster with unexpectedly hot gas, suggesting cosmic structures formed faster than once ...

An international team of astronomers led by Canadian researchers has found something the universe wasn't supposed to have: a ...

Raise a toast to another orbit around the sun with a new NASA image of sparkling galaxy clusters fittingly dubbed the ...

The Champagne Cluster is a rare and beautiful example of two galaxy clusters smashing together. Its festive name comes from ...

A new composite image reveals the “Champagne Cluster” as two massive galaxy clusters caught in a rare, violent collision.