Free Astronomy Magazine January-February 2026

13 ASTRO PUBLISHING tectable in infrared or radio wave- lengths and was found nearly 10 billion light-years from Earth, about 6.5 billion years after the Big Bang. Its detection was made possible by the gravitational imaging method, which sensitively maps how light from background sources is bent by otherwise invisible mass. The mass concentration, labeled “V” in the study, has a cylindrical mass of 1.13 billion solar masses within an 80-parsec radius. This is a level of precision and distance never achieved before for objects this small and dim. “Finding dark mat- ter clumps like this is a critical test of our understanding of how galax- ies form,” said Dr. Devon Powell (Max Planck Institute for Astro- physics), lead author of the com- panion paper in Nature Astronomy . “The discovery fits beautifully with the number of dark objects we ex- pected to find, but every new de- tection helps refine or challenge our theories.” To achieve this, the team developed advanced compu- tational algorithms and harnessed supercomputers to process and model vast datasets. “We expect every galaxy, including our own Milky Way, to be filled with dark matter clumps, but finding them and convincing the community that they exist requires a great deal of number crunching,” said Dr. Simona Vegetti (Max Planck Institute for Astrophysics). Their approach will allow astronomers to probe the structure of dark matter across cos- mic time, opening the door to dis- covering more such objects and examining whether current theo- ries about galaxy formation stand up to scrutiny. The observations fur- ther highlight the power of assem- bling radio telescopes worldwide to push the limits of sensitivity and an- gular resolution. The NSF GBT and NSF VLBA, both operated by the NSF NRAO under cooperative agreement by Associ- ated Universities, Inc., played cru- cial roles in this historic discovery. As the team continues to survey additional lensing systems, any fu- ture findings will help determine whether the abundance and nature of these dark objects are consistent with the fundamental theories gov- erning our Universe. JANUARY-FEBRUARY 2026 T he black ring and central dot show infrared image of a distant galaxy distorted by a gravitation lens. Orange/red shows radio waves from the same object. The inset shows a pinch caused by another, much smaller, dark gravitational lens (white blob). [D. M. Powell, J. P. McKean et al.] images. “We immediately saw a tell-tale pinch in the gravitational arc,” said Professor John McKean, lead author of the paper presenting the beautiful gravitational lensing image. “Only a small clump of mass—an otherwise invisible dark object—could account for this anomaly in the lensing arc.” The newly characterized object is unde- !