A mysterious glow is coming from the middle of our galaxy – and scientists say it could help explain the universe

There is a mysterious glow coming from the middle of our galaxy – and scientists say it could help solve one of the universe’s deepest mysteries.

The diffuse glow of gamma rays towards the heart of the Milky Way has been unexplained for decades. But researchers believe that it could be the result of colliding pieces of dark matter, or the spinning of neutron stars.

If the explanation is the former, and the glow comes from dark matter, it might be the first ever proof that it actually exists.

“Dark matter dominates the universe and holds galaxies together. It’s extremely consequential and we’re desperately thinking all the time of ideas as to how we could detect it,” said co-author Joseph Silk, a professor of physics and astronomy at Johns Hopkins, in a statement.

“Gamma rays, and specifically the excess light we’re observing at the centre of our galaxy, could be our first clue.”

In a new study, scientists made a map of where they expected dark matter to be found in the Milky Way. In its early years, smaller systems of dark matter and other material came into the galaxy towards its centred and clustered together, increasing the number of collisions between dark matter.

Those maps are part of a set of evidence that suggests that the glow of gamma rays at the middle of the Milky Way are coming from dark matter. The simulations show the same signal and characteristics as those found in the real world, they say.

But they note that old neutron stars that are woken back up could also be emitting light that would also explain many of the same pieces of evidence. But, for that theory to work, scientists have to change the maths slightly to suggest there are more of those pulsars in existence than they actually see.

Researchers hope that another experiment will finally provide more certainty – and could give the first proof of dark matter. If the gamma rays have higher energy, they are probably those stars, while lower energy rays probably come from collisions between dark matter.

“A clean signal would be a smoking gun, in my opinion,” Silk said.

Until then, they hope to do similar simulations of other galaxies around the Milky Way, and then compare that to the data.

“It’s possible we will see the new data and confirm one theory over the other,” Silk said. “Or maybe we’ll find nothing, in which case it’ll be an even greater mystery to resolve.”