Webb creates the most detailed map of the cosmic web ever made – Earth.com

The James Webb Space Telescope (JWST) has produced the most detailed map to date of the cosmic web, the largest structure in the known universe. This high-resolution mapping allows astronomers to trace the network of galaxies and the dark matter that guides their growth, reaching back to a period when the universe was only one billion years old.

The cosmic web serves as the universe’s underlying architecture, consisting of a vast, skeleton-like framework. This structure is composed of interwoven filaments and sheets of gas and dark matter that surround immense, nearly empty voids, linking galaxies and clusters into a single, intricate network.

The mapping effort was led by researchers at the University of California, Riverside, and the findings were published in The Astrophysical Journal. The study utilized data from the COSMOS-Web survey, which is the largest General Observer (GO) program selected for the JWST. The GO program is the primary mechanism through which astronomers secure access to the telescope for specific research objectives.

The COSMOS-Web survey covered a contiguous area of the sky approximately the size of three full moons. By leveraging the JWST’s infrared instruments, the international team was able to detect faint, distant galaxies that remained invisible to previous observatories. These instruments allow scientists to peer through cosmic dust and observe the universe’s history across 13.7 billion years.

A primary focus of the research was the visualization of dark matter, which does not emit, reflect, absorb, or block light. Because dark matter passes through regular matter and remains invisible to traditional photography, the team mapped it by observing its gravitational effects. The gravity exerted by dark matter subtly bends the path of light traveling from distant galaxies toward Earth, a process that allows researchers to pinpoint the location of invisible mass.

The resulting maps place invisible mass alongside normal matter, illustrating where the two overlap and how they both stretch into long, threadlike shapes across space. These formations are particularly evident in giant galaxy clusters that span millions of light-years.

The resolution of this new map represents a significant technical leap over previous astronomical efforts. According to Diana Scognamiglio, an astrophysicist at NASA’s Jet Propulsion Laboratory and lead author of the paper, the map is twice as sharp as any dark matter map produced by other observatories.

Previously, we were looking at a blurry picture of dark matter. Now we’re seeing the invisible scaffolding of the universe in stunning detail, thanks to Webb’s incredible resolution.

Diana Scognamiglio

This “invisible scaffolding” is critical to the evolution of the cosmos. Dark matter outmasses visible matter and has functioned as a guide for the universe since its beginning, influencing the formation of galaxies and planets, including Earth.

The map provides a visual history of the universe, with specific regions highlighting different densities of matter. In the COSMOS-Web data, bright yellow regions indicate the dense clusters and filaments of the cosmic web, while dark regions mark the near-empty voids that exist between these structures.

The capability of the JWST to perform this mapping is rooted in its extraordinary sensitivity. By capturing light from the earliest stages of cosmic history, the telescope has transformed the ability of astronomers to study every phase of the universe’s development.

The data gathered from the COSMOS-Web survey provides a comprehensive look at how galaxies form a network across billions of years. By tracing these connections back to the universe’s first billion years, researchers can better understand the mechanisms that drove the distribution of matter on the largest possible scale.