This image shows the spread of galactic haze as seen by the ESA's Planck satellite in the microwave end of the spectrum superimposed over NASA's Fermi Gamma-ray Space Telescope.

This image shows the spread of galactic haze as seen by the ESA’s Planck satellite in the microwave end of the spectrum superimposed over NASA’s Fermi Gamma-ray Space Telescope.

It’s still proving elusive, but scientists have a new theory that may explain what makes up the bulk of the universe — dark matter.

Space.com reports that the European Space Agency, using its Planck satellite, have been studying radiation coming from the center of the Milky Way galaxy.

“The radiation cannot be explained by the structural mechanisms in the galaxy, and it cannot be radiation from supernova explosions,” study co-author Pavel Naselsky of the Niels Bohr Institute at the University of Copenhagen in Denmark said in a statement on Space.com. “We believe that this could be proof of dark matter … Otherwise, we have discovered (an) absolutely new mechanism of acceleration of particles in the galactic center.”

Fascinating stuff from a scientific perspective. A 2004 study from ESA Planck researchers and NASA’s Wilkinson Microwave Anisotropy Probe first reported on this “dark haze,” and it has driven scientists ever since.

In their latest attempt at an explanation, the Planck and WMAP researchers determined that the radiation comes from “Synchrotron emission,” which is created when atomic particles run across space at breakneck speed at the center of the galaxy, Space.com says. If that is the case, the haze could be the calling card for dark matter.

Dark matter is believed to make up 22 percent of the universe. “Normal” matter is just four percent, and the remaining 3/4 of the universe is the even more elusive “dark energy,” according to Space.com.