Not a ton is known about the origins of the universe; science makes new discoveries seemingly every day. Galaxies in particular present a quandary: With their massive gravitational forces, how do they form and interact with one another? Do they collide catastrophically (hopefully not often)? Do they swarm haphazardly, like giant cosmic bees? No, say scientists at the University of Sydney – smaller galaxies instead “dance” around larger ones in orderly, disc-shaped orbits.

“Early in 2013 we announced our startling discovery that half of the dwarf galaxies surrounding the Andromeda Galaxy are orbiting it in an immense plane” said Professor Geraint Lewis of the University of Sydney’s school of physics. “This plane is more than a million light years in diameter, but is very thin, with a width of only 300 000 light years.”

Previously, computer models suggested that smaller dwarf galaxies should orbit more massive ones (like our own Milky Way) in random patterns, similar to how electrons orbit an atom’s nucleus. That’s apparently not the case. Noting the orderly fashion in which dwarf galaxies (which are still large, containing billions of stars) orbit Andromeda, they used the Sloan Digital Sky Survey to dig deeper into the universe.

“Everywhere we looked we saw this strangely coherent coordinated motion of dwarf galaxies. From this we can extrapolate that these circular planes of dancing dwarfs are universal, seen in about 50 percent of galaxies,” said Professor Lewis.

They aren’t sure why this is, and it creates a problem in that it conflicts with our understanding of the universe and dark matter. They suspect that there may be as-yet unseen forces governing the flow of cosmic gasses, but that’s purely speculation at this point. Some experts have made the unsettling suggestion that the phenomena is the result of the bending of gravitational and physical laws, a notion Lewis calls “unpalatable.”

“but if our observations of nature are pointing us in this direction, we have to keep an open mind. That’s what science is all about,” he said.