In a remarkable new study, two teams of astronomers have found the missing matter that connects all the galaxies in the universe, which could revolutionize the way we understand how galaxies formed after the Big Bang. One of the most vexing and important challenges in science is understanding the mysterious nature of dark matter and dark energy, and its role in the universe, and this discovery may be a giant step forward toward that end.

While dark matter and dark energy make up the vast majority of the known universe, we’re still trying to wrap our heads around ordinary, visible matter. But while we can observe a lot of ordinary matter, up until now we had been able to see about half of what we know must be out there that fills the gaps between the galaxies and stars and many other cosmic objects out there.

Two teams – one at the Institute of Space Astrophysics (IAS) in France and the other at the University of Edinburgh – were able to find the matter, which exists as hot, diffuse gas that links the galaxies. It’s been difficult to detect this matter with X-ray telescopes, but the teams were able to figure it out by observing the Sunyaev-Zel’dovich effect, when light that has been left over from the Big Bang passes through the gas.

“Everybody sort of knows that it has to be there, but this is the first time that somebody – two different groups, no less – has come up with a definitive detection,” said Harvard-Smithsonian Center for Astrophysics in Massachusetts professor Ralph Kraft, who wasn’t involved in either study, in an interview with New Scientist. “This goes a long way toward showing that many of our ideas of how galaxies form and how structures form over the history of the universe are pretty much correct.”