Astronomers have peered into the early universe and spotted a trove of baby galaxies huddled together, in what may be the oldest galactic clusters yet discovered.

Galaxies like our Milky Way cluster together today, but how they formed these cosmic clubs has remained a mystery until now.

Light from these newborn galaxies traveled vast distances—10 billion to 11 billion light-years—to reach the two space telescopes that detected them. So the light we see now shows the galaxies as they were some 10 billion to 11 billion years ago. The universe itself is thought to be 13.8 billion years old.

That places the newly discovered clusters very early in the universe's history, Brenda L. Frye of the University of Arizona's Steward Observatory