What used to look like a single structure now resolves into many
Across a patch of sky no wider than three full moons, humanity has now traced the invisible architecture that holds the universe together. Using the James Webb Space Telescope and a catalog of 164,000 galaxies, researchers at UC Riverside have mapped the cosmic web — the vast network of dark matter filaments and voids that structures all of existence — with a clarity and depth never before achieved. The map reaches back 13.7 billion years, to a universe barely one billion years old, offering the clearest view yet of how galaxies have grown and connected across the whole of cosmic time. In seeing this structure, we do not merely observe the universe; we begin, at last, to read it.
- The universe has a skeleton — dark matter filaments threading galaxies together across billions of light-years — and until now, our instruments were too blunt to see it clearly.
- Where Hubble saw blurred, indistinct formations, JWST's infrared sensitivity resolves them into sharp, distinct structures, collapsing what once looked like single features into many separate ones.
- A graduate student-led team spanning ten countries analyzed 164,000 galaxies to place each one into its precise slice of cosmic time, sharpening the map's resolution to an unprecedented degree.
- The cosmic web can now be traced to an era when the universe was barely a billion years old — a window of time that had been effectively unreachable before this survey.
- The full galaxy catalog, mapping pipeline, and an animated visualization of cosmic evolution have been released publicly, opening the research to scientists worldwide.
When astronomers turned the James Webb Space Telescope toward a patch of sky no larger than three full moons, they found not chaos but architecture. A team led by UC Riverside researchers has now mapped that architecture with greater precision than ever before — tracing the dark matter filaments and vast voids that form the universe's large-scale structure across more than thirteen billion years of cosmic history.
The cosmic web is the true shape of everything that exists: an enormous framework of filaments connecting galaxy clusters like threads in a tapestry, with near-empty voids stretching between them. To map it, the team analyzed 164,000 galaxies from the COSMOS-Web survey, the largest observing program yet conducted with JWST since its 2021 launch, with results published in The Astrophysical Journal.
What makes the achievement possible is JWST's infrared sensitivity. The telescope detects galaxies too faint for Hubble to see, peers through dust clouds that block visible light, and measures galactic distances with far greater precision. As lead researcher Hossein Hatamnia explains, each galaxy can now be placed into the correct slice of cosmic time — sharpening the map's resolution dramatically. When his advisor Bahram Mobasher compared the new data to earlier Hubble observations, structures that had appeared merged suddenly separated into distinct features, and an era when the universe was only a few hundred million years old became visible for the first time.
The collaboration spans ten countries, and the team has committed to open science — releasing the full galaxy catalog, the mapping pipeline, and a video of the cosmic web evolving across billions of years. What emerges is not merely a technical achievement but a new way of seeing: the universe is organized, connected, and structured, and now, at last, we can see that structure clearly.
When astronomers point the James Webb Space Telescope at a patch of sky no larger than three full moons, they see not chaos but architecture. A team led by researchers at UC Riverside has now mapped this architecture with the greatest precision yet—tracing the invisible skeleton that holds the universe together across more than thirteen billion years of cosmic history.
The cosmic web is the universe's true structure. Beneath the scattered light of individual galaxies lies an enormous framework of dark matter and gas, arranged in filaments and sheets that stretch across unimaginable distances. These filaments connect galaxy clusters like threads in a vast tapestry. Between them lie voids—regions of near-emptiness so large they dwarf anything in the observable universe. This is the large-scale shape of everything that exists.
To see it, the team analyzed 164,000 galaxies using data from the COSMOS-Web survey, the largest observing program yet conducted with the James Webb Space Telescope since its launch in 2021. The results, published in The Astrophysical Journal, reveal something that earlier telescopes could only hint at: the cosmic web in its full, intricate detail, reaching back to when the universe was barely a billion years old.
What makes this possible is JWST's infrared sensitivity. The telescope detects galaxies so faint that previous instruments, including the Hubble Space Telescope, simply could not see them. It peers through clouds of cosmic dust that would block visible light. And it measures the distances to these galaxies with far greater precision than before. Hossein Hatamnia, the graduate student who led the study, explains the compounding effect: "The telescope detects many more faint galaxies in the same patch of sky, and the distances to those galaxies are measured far more precisely. Each galaxy can therefore be placed into the correct slice of cosmic time, sharpening the map's resolution."
The improvement over previous observations is striking. When Bahram Mobasher, Hatamnia's advisor at UC Riverside, compared the new JWST data to earlier Hubble observations of the same region, structures that had appeared blurred together suddenly separated into distinct features. What looked like a single formation resolved into many. Details that had been smoothed away became sharp and visible. The team could now see the cosmic web at a time when the universe was only a few hundred million years old—an era that had been essentially unreachable before.
The research represents a collaboration spanning ten countries: the United States, Denmark, Chile, France, Finland, Switzerland, Japan, China, Germany, and Italy. But it also represents a commitment to open science. The team has released the mapping pipeline, the catalog of 164,000 galaxies, and even a video showing the cosmic web evolving across billions of years. Any researcher with the curiosity to look can now access the data and build on these findings.
What emerges from this work is a new understanding of how galaxies have evolved within the cosmic web over time. The universe is not a random scatter of light. It is organized, structured, connected—and now, for the first time, we can see that organization with genuine clarity.
Citas Notables
For the first time we can study the evolution of galaxies in cluster and filamentary structures across cosmic time, all the way from when the universe was a billion years old up to the nearby universe.— Hossein Hatamnia, lead author, UC Riverside and Carnegie Observatories
The jump in depth and resolution is truly significant, and we can now see the cosmic web at a time when the universe was only a few hundred million years old, an era that was essentially out of reach before JWST.— Bahram Mobasher, UC Riverside
La Conversación del Hearth Otra perspectiva de la historia
When you say the cosmic web, are you talking about something you can actually see, or is this more of a mathematical model?
It's both. The filaments are made of real dark matter and gas. You can't see dark matter directly, but you can see its gravitational effects on the galaxies it holds. JWST lets us map where those galaxies are, and from that distribution, we can infer the underlying structure.
So JWST didn't discover the cosmic web—it just made it visible in a new way?
Exactly. Astronomers have known about the cosmic web for decades. But this is the first time we've been able to see it with this kind of detail and reach back this far in time. It's like the difference between knowing a city exists and actually being able to see its streets.
Why does it matter that we can see it at a billion years old versus, say, five billion years old?
Because the universe was still very young then. If we can understand how the cosmic web was organized when it was barely a billion years old, we learn something fundamental about how structure formed in the first place. It tells us about the earliest stages of galaxy assembly.
And the fact that they released all this data publicly—is that unusual?
Not for this team. COSMOS has always been an open-science project. But the scale here is significant. 164,000 galaxies, the mapping tools, the video of evolution over time. It's all available. Other researchers can now ask their own questions of this data.
What's the next question?
How did galaxies in these filaments evolve differently from galaxies in the voids? How did the cosmic web itself change shape over time? There's a lot still to understand.