An astrophysicist from the University of Tokyo has published a study claiming to provide the first direct evidence of dark matter, the mysterious substance thought to make up 27% of the universe. Professor Tomonori Totani analysed data from NASA's Fermi Gamma-ray Space Telescope and detected gamma rays emanating from the centre of the Milky Way that he says bear the signature of dark matter.
Dark matter was first proposed in the 1930s by Swiss astronomer Fritz Zwicky, who observed that galaxies were spinning faster than their visible mass could explain. Since then, scientists have searched for dark matter particles using ground-based detectors, space telescopes, and the Large Hadron Collider, but without success.
Totani's research, published in the Journal of Cosmology and Astroparticle Physics, focuses on the theory that dark matter is composed of weakly interacting massive particles (WIMPs). When two WIMPs collide, they annihilate each other, releasing gamma rays. Totani found a pattern of gamma rays that matches the predicted shape of the dark matter halo surrounding the galaxy.
If confirmed, the discovery would be a major breakthrough. However, other astrophysicists have urged caution. Professor Justin Read of the University of Surrey noted that the lack of similar signals from dwarf galaxies argues against the dark matter interpretation. Professor Kinwah Wu of University College London added that extraordinary claims require extraordinary evidence, and this analysis has not yet reached that status.
