Liputan6.com, Jakarta A startling scientific claim came from Professor Tomonori Totani of the University of Tokyo's Department of Astronomy in November 2025.
As reported by Gazetta Express, he claimed to have detected the first direct evidence for the existence of dark matter, a hypothetical form of matter whose existence had previously only been speculated about.
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This discovery was made through analysis of data from NASA's Fermi Gamma-ray Space Telescope, focusing on a specific gamma-ray signal predicted to originate from the annihilation of theoretical dark matter particles.
If this claim proves correct, it would be a historic moment that would revolutionize our understanding of the composition and structure of the universe.
Professor Totani observed gamma rays with photon energies of 20 gigaelectronvolts (GeV) forming a halo-like structure around the center of the Milky Way galaxy.
First Direct Detection Claim: Gamma Ray Signal from WIMPs
Professor Tomonori Totani analyzed data from NASA's Fermi Gamma-ray Space Telescope, searching for a specific gamma-ray signal.
This signal is predicted to arise from the annihilation of dark matter particles, specifically WIMPs, which are a leading candidate for dark matter.
The detection revealed gamma rays with photon energies of 20 GeV extending in a halo-like structure toward the center of the Milky Way galaxy.
This component of the gamma-ray emission closely matches the expected shape of a dark matter halo, strongly indicating that it is a trace of this mysterious matter.
The measured gamma-ray energy spectrum also matches the predicted rate for the annihilation of WIMPs with masses approximately 500 times the mass of a proton.
Totani stated that this gamma-ray emission is not easily explained by other common astronomical phenomena, strengthening the suspicion of dark matter detection.
"While the GC radiation is concentrated at the center of the galaxy, my halo signal is thinly spread throughout the region. I think this strongly indicates radiation from dark matter," he said.
The study, published in the Journal of Cosmology and Astroparticle Physics, marks a potentially major discovery in astronomy and physics.
If proven correct, it would demonstrate that dark matter is a new particle not included in the current Standard Model of particle physics, paving the way for further research.
Although Professor Totani is confident in his findings, he emphasized the importance of verification through independent analysis by other researchers.
The Mystery of Dark Matter: Definition and Cosmic Role
Dark matter is a hypothetical form of matter that does not interact with light or other electromagnetic radiation, making it invisible and unobservable directly.
Its existence is inferred from its gravitational effect on visible matter in the universe, such as stars and galaxies.
This mysterious matter is estimated to constitute about 27% of the total mass-energy of the universe.
Together with dark energy, which accounts for about 68%, they constitute nearly 95% of our universe, while ordinary matter, as we know it, accounts for less than 5%.
Dark matter's role is crucial; it acts as the "invisible glue" that holds stars, dust, and gas together in galaxies.
The most common explanation for dark matter is that it consists of as-yet-undiscovered subatomic particles, such as Weakly Interacting Massive Particles (WIMPs), or axions.
WIMPs are prime candidates, predicted to annihilate each other and release other particles, including gamma-ray photons, when they collide.
History and Indirect Evidence of Dark Matter
The concept of dark matter was first proposed in the early 1930s by Swiss astronomer Fritz Zwicky.
He observed that galaxies in the Coma cluster were moving faster than expected based on their apparent mass, implying the presence of invisible matter holding the cluster together.
In the 1970s, Vera Rubin also found strong evidence for the existence of dark matter through her study of galaxy rotation curves.
Her observations showed that stars at the edges of galaxies rotated as fast as those at the center, which could only be explained by the presence of an invisible mass that distributed gravity evenly.
Other indirect evidence includes the gravitational lensing of background objects by galaxy clusters, the temperature distribution of hot gas in galaxies and clusters, and the anisotropic pattern in the cosmic microwave background.