It has been nearly a century since astronomers first hypothesized the existence of an invisible material weaving a cosmic web between galaxies. While the reality and composition of this so-called "dark matter" remain unproven, this study claims to have potentially glimpsed the first direct evidence of the elusive substance.

Although further analysis is required to eliminate standard astronomical explanations, confirming this discovery would represent a historic turning point in the decades-long search for the material thought to comprise 27% of the universe.

“This could be a crucial breakthrough in unraveling the nature of dark matter,” said Prof Tomonori Totani, an astrophysicist at the University of Tokyo. He suggests that gamma rays radiating from the center of the Milky Way may carry the specific signature of the particle.

The concept of dark matter was originally formulated in the 1930s by Swiss astronomer Fritz Zwicky. He observed that distant galaxies were rotating far faster than their visible mass should allow, leading to the theory that an unseen material was exerting the necessary gravitational pull to hold them together.

Scientists have been hunting for these particles ever since, yet ground-based detectors, space telescopes, and massive particle accelerators like the Large Hadron Collider have all failed to produce a confirmed signal.

One leading theory posits that dark matter consists of "weakly interacting massive particles," or Wimps. These theoretical particles are heavier than atomic protons but rarely interact with visible matter. However, when two Wimps collide, they are expected to annihilate each other, releasing a burst of secondary particles and gamma rays.

Utilizing data from Nasa’s Fermi Gamma-ray Space Telescope—which scans the cosmos for the highest-energy photons—Totani identified a specific pattern of gamma rays. This pattern appears to align with the theoretical shape of the dark matter "halo," a sphere of density spreading outward from the galactic core.

Totani told the Guardian that the signal “closely matches the properties of gamma-ray radiation predicted to be emitted by dark matter.” The findings have been published in the Journal of Cosmology and Astroparticle Physics.

If Totani’s observations are correct, they imply that dark matter consists of elementary particles roughly 500 times more massive than a proton. However, significant work remains to ensure these signals are not merely the result of background astrophysical noise.

Totani noted that the "decisive factor" would be locating gamma rays with an identical spectrum in other areas, such as dwarf galaxies. However, other experts remain skeptical. Prof Justin Read, an astrophysicist at the University of Surrey, argues that the absence of similar signals from dwarf galaxies strongly suggests Totani has not observed dark matter annihilation.

Prof Kinwah Wu, a theoretical astrophysicist at UCL, also advised caution regarding the findings. “I appreciate the author’s hard work and dedication, but we need extraordinary evidence for an extraordinary claim,” Wu said. “This analysis has not reached this status yet. It is a piece of work which serves as an encouragement for the workers in the field to keep on pressing.”