In a groundbreaking study, scientists leveraged subtle distortions in the shapes of over 250,000 galaxies to construct the most detailed dark matter map to date, paving the way for insights into some of the universe’s greatest enigmas.

Dark matter, elusive by nature, does not emit any detectable light. Its existence can only be inferred through its gravitational interactions with normal matter. Researchers, including Jacqueline McCreary from Northeastern University, utilized the James Webb Space Telescope (JWST) to map a region of the sky larger than the full moon.

“This high-resolution image depicts the scaffold of a small segment of the universe,” noted McCreary. The new map boasts double the resolution of previous ones created by the Hubble Space Telescope, encompassing structures much farther away.

The researchers studied approximately 250,000 galaxies, noting that their shapes, while interesting, serve primarily as a backdrop for understanding gravitational distortions. As Liliya Williams from the University of Minnesota explained, “These galaxies merely act as the universe’s wallpaper.” The critical component is the way dark matter’s gravitational pull warps the light from these distant galaxies—a phenomenon known as gravitational lensing. The more distorted the shape of these galaxies is from a perfect circle, the greater the amount of dark matter situated between us and them.

By analyzing these optical distortions, the team was able to derive a map illustrating massive galaxy clusters and the cosmic web filaments linking them. Many of these newly identified structures deviate from prior observations of luminous matter, suggesting they are predominantly composed of dark matter. “Gravitational lensing is one of the few and most effective techniques for detecting these structures across vast regions,” Williams stated.

This research is significant, considering that dark matter constitutes about 85% of the universe’s total matter, crucial for the formation and evolution of galaxies and clusters. Understanding its distribution could shed light on its behavior and composition, according to Williams.

“This achievement is not just observational but also paves the way for various analyses, including constraints on cosmological parameters, the relationship between galaxies and their dark matter halos, and their growth and evolution over time,” McCreary highlighted. These parameters include the strength of dark energy, the enigmatic force driving the universe’s accelerating expansion.

While initial findings from the JWST map align with the Lambda CDM model of the universe, McCreary emphasizes that a thorough analysis of the data is still required to unearth new insights. “At first glance, it appears consistent with Lambda CDM, but I remain cautious. A final assessment will depend on complete results.”