# Discovery and mapping of COSMOS-z3.1-A proto-supercluster

> Live situation record from CLSTR: https://clstr.news/situations/discovery-and-mapping-of-cosmos-z31-a-proto-supercluster
> Updated: 2026-09-12T11:51:00.000Z. Sources: 4. Developments: 2.

Astronomers have identified and mapped COSMOS-z3.1-A, the earliest and most distant proto-supercluster ever detected. Located approximately 12 billion light-years away, the structure existed when the universe was roughly 2.1 billion years old and possesses a mass estimated at 5,000 times that of the Milky Way.

Research utilizing data from the Dark Energy Camera and the ODIN survey has allowed for the reconstruction of three-dimensional maps of two enormous protoclusters, COSMOS-z3.1-A and COSMOS-z3.1-C. COSMOS-z3.1-A specifically contains 10 distinct density peaks connected by filaments of galaxies and matter. These findings support the “bottom-up” model of cosmic evolution, suggesting that smaller concentrations of matter merge along filaments to form the massive galaxy clusters observed in the modern universe.

## Timeline

### 2026-09-12: Astronomers map massive COSMOS-z3. 1-A protosupercluster

Astronomers have discovered and mapped COSMOS-z3. 1-A, a massive protosupercluster 12 billion light-years away that existed when the universe was only 2.1 billion years old.

2 sources. https://clstr.news/cluster/astronomers-map-massive-cosmos-z3-1-a-protosupercluster

### 2026-09-09: Astronomers discover earliest proto-supercluster and study primordial helium

Astronomers have discovered the earliest known proto-supercluster, COSMOS-z3.1-A, and used helium measurements in distant galaxies to confirm theories regarding the Big Bang and early elemental dispersal.

2 sources. https://clstr.news/cluster/astronomers-discover-earliest-proto-supercluster-and-study-primordial-helium

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Cite as: Discovery and mapping of COSMOS-z3.1-A proto-supercluster. CLSTR, https://clstr.news/situations/discovery-and-mapping-of-cosmos-z31-a-proto-supercluster