Astronomers Find Galaxy Similar to Milky Way More Than 12 Billion Light-Years Away

Courtesy of Rizzo et al./ALMA/European Southern Observatory

Our Milky Way galaxy has a bit of a look-alike in an unlikely place: the early universe.

Astronomers used ALMA, or the Atacama Large Millimeter/submillimeter Array of telescopes, based in Chile, to find the galaxy, located more than 12 billion light-years away from our own.

That means the light from this galaxy has traveled for more than 12 billion years to reach us, so we’re seeing the galaxy as it appeared when the universe was only 1.4 billion years old.

The telescope’s image of the galaxy and accompanying study was published Wednesday in the journal Nature.

During the tumultuous early years of the universe, galaxies were likely just as unstable as they formed, lacking the structure associated with older galaxies like the Milky Way.

Astronomers using ALMA, in which the ESO is a partner, have revealed an extremely distant galaxy that looks surprisingly like our Milky Way. The galaxy, SPT0418-47, is gravitationally lensed by a nearby galaxy, appearing in the sky as a near-perfect ring of light. Courtesy of Rizzo et al./ALMA/European Southern Observatory

But the image of this galaxy challenges that theory, and it could change how astronomers understand galaxy formation as well as the early days of the universe.

“This result represents a breakthrough in the field of galaxy formation, showing that the structures that we observe in nearby spiral galaxies and in our Milky Way were already in place 12 billion years ago,” said Francesca Rizzo, study author and postdoctoral student at the Max Planck Institute for Astrophysics in Germany, in a statement.

The galaxy, named SPT0418-47, has two hallmarks of our galaxy, including its rotating disk-like structure as well as the bulge, or large group of stars corralled around the galaxy’s center. This bulge of stars has never been seen this far back in the history of the universe.

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“The big surprise was to find that this galaxy is actually quite similar to nearby galaxies, contrary to all expectations from the models and previous, less detailed, observations,” said Filippo Fraternali in a statement, study co-author and professor of gas dynamics and evolution of galaxies at the Kapteyn Astronomical Institute of the University of Groningen in the Netherlands.

Studying this galaxy allows astronomers to essentially peer back in time to when the universe was 10 percent of its current age.

Given the distance of this galaxy, the researchers used a technique called gravitational lensing while observing with ALMA. This uses the gravity of nearby galaxies to magnify distant galaxies by bending their light.

Due to gravitational lensing, the image shows SPT0418-47 as a ring of light around another galaxy. Computer modeling helped the researchers to reconstruct the actual shape of the galaxy.

“When I first saw the reconstructed image of SPT0418-47 I could not believe it: a treasure chest was opening,” Rizzo said.

Instead of the young, chaotic galaxy they expected, the researchers found unexpected structure and order in the galaxy—as though it belonged to one that was much older.

“What we found was quite puzzling; despite forming stars at a high rate, and therefore being the site of highly energetic processes, SPT0418-47 is the most well-ordered galaxy disc ever observed in the early Universe,” said Simona Vegetti, study co-author and Max Planck Research Group Leader at the Max Planck Institute for Astrophysics, in a statement.

“This result is quite unexpected and has important implications for how we think galaxies evolve.”

Over time, the galaxy likely evolved differently than our own, the researchers said. The Milky Way is a spiral galaxy, but the researchers believed this one became an elliptical galaxy.

Future observations with more powerful telescopes may help astronomers uncover how common these well-ordered galaxies were after the Big Bang.

CNN Wire contributed to this report.