James Webb finds galaxy cluster XLSSC 122 with strong gravitational lensing

NASA's James Webb Space Telescope revealed that galaxy cluster XLSSC 122, about 10.4 billion light-years away, shows the most distant strong gravitational lensing ever seen. Its unusually concentrated central mass conflicts with standard cosmological model predictions. Three studies were presented at the 248th AAS meeting on June 17, 2026.

• XLSSC 122 lies roughly 10.4 billion light-years from Earth
• It is the most distant cluster with strong gravitational lensing
• Dark matter accounts for most of the lensing effect
• Its mass concentration disagrees with cosmological model predictions