A team of international scientists has released the largest-ever map of the universe, revealing nearly 800,000 galaxies—many of them from the early days of the cosmos.
Built using data from NASA’s powerful James Webb Space Telescope (JWST), the project, called COSMOS-Web, gives us an incredibly detailed look at how the universe looked across almost all of its 13.8-billion-year history.
Led by physicists Caitlin Casey from UC Santa Barbara and Jeyhan Kartaltepe from the Rochester Institute of Technology, the team set out to create the deepest and widest map of the universe ever made.
The result is astonishing in scale. Casey explained that if the well-known Hubble Ultra Deep Field image was printed on a regular piece of paper, the COSMOS-Web image would be the size of a 13-foot by 13-foot mural—just as deep but covering a much wider view.
This massive image reaches back 13.5 billion years, covering 98% of all time since the Big Bang.
It shows galaxies from different eras, including some of the very first ones formed.
Scientists hoped not only to spot faraway galaxies but also to understand the environments they lived in—how they were clustered in dense areas or surrounded by empty space.
Before JWST began collecting data, astronomers expected only a few galaxies to exist within the first 500 million years after the Big Bang.
That’s because forming stars and galaxies takes time. But when the telescope looked deeper, it found around ten times more early galaxies than expected—including some with supermassive black holes.
These findings are shaking up existing theories. “It’s a big surprise,” said Casey. “We’re seeing galaxies and black holes we didn’t expect to find so early. It raises a lot of new questions about how the universe formed and evolved.”
Some scientists are even wondering if our basic understanding of the universe needs to be updated. One puzzle is how the early universe could produce so many stars and such bright galaxies in just a few hundred million years. The light from these objects seems to appear too early to fit current models.
To help solve these mysteries, the COSMOS team is making their data public. They’ve spent the last two years turning the telescope’s raw data into images and catalogs that other scientists—including students—can explore. The idea is that more eyes on the data can lead to new discoveries.
The team isn’t stopping here. They’re already planning more observations and will use a technique called spectroscopy to measure the distances to the oldest galaxies and learn more about the chemical elements inside them.
The COSMOS-Web image and data are now available online, and scientific papers about the project are being submitted to major astronomy journals. As Casey puts it, this is just the beginning: “There’s a lot left to learn, and we’ve only scratched the surface.”
