Meet the BOSS, the Largest Structure in the Universe (So Far)

Astronomers recently discovered a wall of galaxies 1 billion light years across, larger than anything else yet identified in the cosmos

Superclusters
An illustration of galaxy superclusters and cosmic voids, similar to the structure of the BOSS Great Wall Science Photo Library/Corbis

The English language has a few limitations. One such problem is describing size—words like big, humongous and immense don’t come close to describing the objects astronomers are discovering in deep space. There are definitely no words to describe their latest find, dubbed the BOSS Great Wall, which is a supercluster of galaxies over 1 billion light years across, making it the largest structure observed in the universe so far.

The BOSS is named after the Baryon Oscillation Spectroscopic Survey—an international effort to map galaxies and quasars in the early universe—and is like cosmic webbing. This wall is made up of 830 separate galaxies that gravity has corralled into four superclusters, connected by massive filaments of hot gas, Joshua Sokol reports for New Scientist. This creates a twisting structure that resembles a cosmic honeycomb.

"On the grandest scales, the universe resembles a cosmic web of matter surrounding empty voids – and these walls are the thickest threads," he writes.

Lurking 4.5 to 6.5 billion lightyears away, the BOSS has an estimated mass 10,000 times greater than our own Milky Way and recently described the find in the journal Astronomy & Astrophysics. 

Sky News explains that the BOSS is two thirds bigger than the previous record holder, the Sloan Great Wall, which was discovered in 2003. It also dwarfs both the CfA2 Wall discovered in 1989 and the Laniakea supercluster—the neighborhood where our own Milky Way resides.  

Not everyone is convinced that the BOSS is truly the biggest, though. “I don’t entirely understand why they are connecting all of these features together to call them a single structure,” Allison Coil of the University of California in San Diego tells New Scientist. “There are clearly kinks and bends in this structure that don’t exist, for example, in the Sloan Great Wall.”

But it’s not really the size of the wall that counts. Superclusters and cosmic walls like the BOSS and Sloan are helping researchers model the physics of the big bang and map the shape of the universe. And, if the pace of research keeps up, it’s unlikely the BOSS will keep the corner office for very long.

Get the latest stories in your inbox every weekday.