Nearly a century after scientists first proposed the existence of an invisible substance shaping the universe, new research claims that the first direct hint of dark matter may finally have been detected. The study examines a pattern of gamma rays near the centre of the Milky Way that appears to echo long-standing predictions about how dark matter should behave. The findings were reported by The Guardian, which highlighted both the excitement and the caution surrounding the claim.

Dark matter was first suggested in the 1930s when the Swiss astronomer Fritz Zwicky noticed that distant galaxies were rotating too quickly to remain intact based on their visible mass alone. This led to the idea of a hidden material that does not emit or absorb light but exerts a gravitational pull on the structures around it. Despite extensive experiments using detectors, space telescopes and particle accelerators, the true nature of dark matter has remained elusive.

Prof Tomonori Totani of the University of Tokyo analysed data from Nasa’s Fermi Gamma-ray Space Telescope, which tracks the most energetic photons known to science. He identified a distinct pattern of gamma rays that appears to follow the expected distribution of a dark matter halo surrounding the Milky Way. According to Totani, the signal closely resembles the type of radiation predicted when two hypothetical dark matter particles, known as wimps, collide and annihilate one another. These particles are thought to be far heavier than protons but almost imperceptible to normal matter. Details of the work have been published in the Journal of Cosmology and Astroparticle Physics.

If the interpretation is correct, the detected particles could be about 500 times more massive than a proton. However, scientists have warned that much more evidence is needed before any firm conclusions can be reached. Totani himself noted that a decisive test would be to detect gamma rays with matching characteristics in other parts of the universe, especially dwarf galaxies that are expected to contain large quantities of dark matter.

Prof Justin Read of the University of Surrey said that the lack of strong signals from dwarf galaxies works against the dark matter explanation. Prof Kinwah Wu of UCL also urged caution, stating that an extraordinary claim needs extraordinary evidence and that the current analysis does not yet meet that standard. He added that the study should be viewed as encouragement for researchers rather than proof of a breakthrough.

The result is intriguing, but many alternative explanations remain possible, including emissions from other astrophysical processes near the galactic centre. Even so, the study has injected fresh energy into a field that has seen many promising signals fade away under scrutiny. If further research supports Totani’s findings, it could mark one of the most significant steps forward in the long search for the nature of dark matter.