Scientists may be a step closer to confirming the long-theorized existence of dark matter, the invisible substance believed to make up nearly 27% of the universe. A new study published in Physical Review Letters analyzed a mysterious gamma-ray glow near the Milky Way’s center that could be evidence of dark matter collisions.
Unlike ordinary matter, which makes up just 5% of the universe and can be observed through light or radiation, dark matter neither emits nor reflects light. Its existence has only been inferred from the gravitational pull it exerts on galaxies and cosmic structures, but it has never been directly observed.
The study examined data from NASA’s Fermi Gamma-ray Space Telescope, focusing on a region approximately 7,000 light-years wide and located 26,000 light-years from Earth. Researchers found that the detected gamma rays could have originated from two possible sources, colliding dark matter particles or millisecond pulsars, which are fast-spinning neutron stars that emit high-energy radiation.
Simulations showed that both explanations are plausible. “We’ve increased the odds that dark matter has been indirectly detected,” said co-author Joseph Silk, a cosmologist at Johns Hopkins University and the Sorbonne.
Scientists expect that future observations from the upcoming Cherenkov Telescope Array in Chile, set to begin operations by 2026, will help determine whether the glow indeed results from dark matter interactions. Until then, the unexplained radiation remains one of the most compelling clues in the ongoing search to solve one of physics’ greatest mysteries.