The galaxies are seen as they existed just 500 million years after the birth of the universe. Their light, traversing the cosmos for more than 13 billion years, was seen only because it was distorted in a natural "gravitational lens" created by the gravity-bending mass of a nearer cluster of galaxies.

The universe is estimated to be 13.7 billion years old, so that puts the newfound galaxies at 13.2 billion light-years away. A light-year is the distance light travels in a year, about 6 trillion miles (10 trillion kilometers).

The galaxies offer a glimpse of an era shortly after the first stars formed.

"That we should find so many distant galaxies in our small survey area suggests they are very numerous indeed," Stark said. "We estimate the combined radiation output of this population could be sufficient to break apart (ionize) the hydrogen atoms in space at that time, thereby ending the Dark Ages."