The largest known object in space that is not a galaxy is a structure called the Hercules-Corona Borealis Great Wall. It is a vast cosmic filament or supercluster of galaxies located about 10 billion light-years away from Earth. The Hercules-Corona Borealis Great Wall was discovered in 2013 through the analysis of data from the Sloan Digital Sky Survey. It stretches over a distance of about 10 billion light-years and contains an estimated 10,000 galaxies. This immense structure is considered one of the largest known coherent structures in the universe.