Decades-old Milky Way mystery may finally be solved after scientists discover new form of dark matter

 Scientists have discovered that a new form of dark matter could simultaneously solve two long-standing mysteries at the heart of our Milky Way.

For decades, astronomers have been puzzled by unusually high ionisation rates in the "central molecular zone" or CMZ near our galaxy's core - in layman's terms, the number of atoms or molecules which lose their electrons in a given timeframe.

The CMZ spans almost 700 light years and contains some of the densest molecular gas in our galaxy.

Scientists have found this region is unusually ionised, with hydrogen molecules splitting into charged particles at a much faster rate than expected.

Researchers have also long detected a strange gamma ray "glow" at an energy of 511 kiloelectronvolts (keV).

Such a glow, first observed in the 1970s, occurs when electrons and their antimatter counterparts, positrons, collide - but its root cause has long remained unclear.

Various explanations, including supernovas, massive stars and black holes, have been proposed, but none fully explain either phenomenon.

But now, both phenomena might have a common explanation, according to a new study published in the Physical Review Letters journal.

Researchers have proposed that a previously overlooked type of dark matter could explain both mysteries simultaneously.

This "light dark matter", with masses of just a few million electronvolts, is far lighter than the particles astronomers typically search for.

The study suggests these particles could interact with their antiparticles in the galactic centre, annihilating each other and producing electrons and positrons.