Mapping Dark Matter

By: Monika Luabeya

14 November 2025 at 12:44

Webb near-infrared data combined with Chandra X-ray data of the Bullet Cluster show many overlapping objects, including foreground stars, galaxies in galaxy clusters, and distorted background galaxies behind the galaxy clusters. The objects are all at various distances set against the black background of space. Most galaxies appear as tiny fuzzy ovals in white, orange, or red. A slightly larger, very bright, light blue spiral galaxy is at center. To its immediate left and right are two large bright pink splotches representing X-rays. The right pink area has a rounded nose facing right, where it is darker pink, and fades to the left as a triangular shape. This is referred to as the Bullet. To the far left and far right, next to the pink regions, are two blue regions representing dark matter mass. The left blue region is a large, long oval at an angle. The blue region at right is a far smaller oval.

NASA, ESA, CSA, STScI, CXC

This image released on June 30, 2025, combines data from NASA’s James Webb Space Telescope and NASA’s Chandra X-ray Observatory to visualize dark matter. Researchers used Webb’s observations to carefully measure the mass of the galaxy clusters shown here as well as the collective light emitted by stars that are no longer bound to individual galaxies.

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Image credit: NASA, ESA, CSA, STScI, CXC