An arc of galaxies 3 billion light-years long may challenge cosmology

The discovery is a “big deal” if true, but still needs to be confirmed

Sloan Digital Sky Survey telescope

Observations of thousands of galaxies taken by the Sloan Digital Sky Survey (pictured) helped reveal a purported giant arc of galaxies, more than 3 billion light-years long.

Patrick Gaulme/Sloan Digital Sky Survey (CC BY 4.0)

A giant arc of galaxies appears to stretch across more than 3 billion light-years in the distant universe.