Scientists may have found a clue to one of the biggest mysteries in the universe—dark matter. This invisible form of matter is believed to make up 85% of all the mass in the universe, yet it has never been directly observed.
Now, researchers have discovered a strange energy source at the center of our galaxy that could be linked to a different type of dark matter than previously thought.
A team of scientists, including Dr. Shyam Balaji from King’s College London, studied a puzzling phenomenon in the Milky Way’s core.
Large clouds of hydrogen gas there are positively charged, which is unusual because hydrogen is usually neutral. This means something must be providing enough energy to knock away electrons from the hydrogen atoms—but what?
For years, scientists suspected that cosmic rays, fast-moving particles from space, were responsible.
However, the energy levels recorded in this region—known as the Central Molecular Zone (CMZ)—do not seem to match what cosmic rays would produce. This led the team to explore a different explanation: dark matter.
Most dark matter studies focus on a type of particle called Weakly Interacting Massive Particles (WIMPs).
These particles are thought to be heavy and difficult to detect because they barely interact with regular matter.
However, this new study, published in Physical Review Letters, suggests that dark matter could be much lighter than previously believed.
The researchers propose that these tiny dark matter particles may be colliding with each other and creating charged particles through a process called “annihilation.”
These new particles could then ionize the hydrogen gas, explaining the mystery at the heart of our galaxy.
“The search for dark matter is like a giant manhunt, but most experiments happen on Earth, waiting for dark matter to come to them,” said Dr. Balaji. “By looking at the center of our galaxy, we are going straight to the source. The data is telling us that dark matter might be lighter than we thought.”
This discovery could also help explain another long-standing mystery—the “511-keV emission line,” a type of X-ray signal found at the Milky Way’s center. Scientists have struggled to understand this signal, but it may also be caused by low-mass dark matter particles colliding and producing energy.
If this theory is correct, it could change how scientists search for dark matter. Instead of focusing only on WIMPs, researchers may need to consider lighter and more active dark matter particles. The findings offer new hope in solving one of the greatest scientific mysteries of our time—what dark matter really is and how it shapes our universe.
Source: King’s College London.
