Webb Telescope Reveals Dark Matter Distribution
Astronomers have created the most detailed map of dark matter in the universe using the James Webb Space Telescope. The map covers a sky area nearly three times the size of the full moon.
What Is Dark Matter?
Ordinary matter, like stars, planets, and people, makes up only about 15% of the universe. The rest is dark matter, invisible because it neither emits nor reflects light. Scientists detect it through its gravitational effects on galaxies and light from distant objects.
Mapping Dark Matter with Gravitational Lensing
The new map used light bending from about 250,000 distant galaxies. This phenomenon, called gravitational lensing, revealed how matter along the line of sight distorts light. Webb’s greater capabilities doubled the resolution of earlier Hubble maps, extended coverage, and looked further back in time, 8 to 10 billion years ago.
Insights into the Cosmic Web
The map shows galaxy clusters, dark matter filaments, and low-density regions, revealing the structure of the universe in unprecedented detail. Webb’s sharper images and more galaxies help create a denser, more accurate map of dark matter.
Implications for Galaxy Formation
Dark matter halos, which act as nurseries for galaxies, guide how galaxies grow and evolve. Knowing the location and density of dark matter allows scientists to improve models of cosmic evolution and understand how the universe formed its spectacular variety of galaxies.
