Astronomers using the Keck I telescope on Mauna Kea have reached back a long time ago to find a gal­axy far, far away.

In fact, it’s the farthest and oldest discovered so far, the scientists said Monday.

And it is surprisingly large and bright, given its youthfulness, they added.

"While we saw the galaxy as it was 13 billion years ago, it had already built more than 15 percent of the mass of our own Milky Way today," said Pascal Oesch of Yale University, lead author of the study, in a release. "But it had only 670 million years to do so. The universe was still very young then."

The galaxy, EGS-zs8-1, is one of the brightest and most massive objects in the early universe and was originally identified in images from NASA’s Hubble and Spitzer space telescopes.

Its precise distance from Earth, 13.1 billion light-years, was determined by a team of astronomers using an infrared spectrograph called MOSFIRE on the Keck. The findings were published Monday in Astrophysical Journal Letters.

The new distance measurement also enabled the astronomers to determine that EGS-zs8-1 was still forming stars very rapidly, about 80 times faster than the Milky Way today.

"Every confirmation adds another piece to the puzzle of how the first generations of galaxies formed in the early universe," said Pieter van Dokkum of Yale, second author of the study. "Only the largest telescopes are powerful enough to reach to these large distances."

Astronomers from the University of Cali­for­nia, Santa Cruz, also took part in the research.