Milky Way’s Twin Causes Rethink of Galactic Evolution

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J.Just like us, galaxies usually go through a difficult time during their adolescence. Recent research has revealed that young galaxies collide and merge with other galaxies, developing clumped, asymmetrical “battle scars” and bursts of stellar activity. It takes billions and billions of years for a galaxy to settle and mature into the majestic spiral arm formations we are familiar with.

At least that’s what we thought.

Astronomers Rashi Jain and Yogesh Wadadekar were recently surprised to discover a relatively young galaxy, in pristine condition, spiral arms and all. Using deep imaging from the James Webb Space Telescope, they observed a galaxy strikingly resembling our 13.6 billion-year-old Milky Way, but which formed only 1.5 billion years after the Big Bang, when the universe was only a tenth of its current age. They named the galaxy “Alaknanda” after one of the two headwaters of the Ganges in India (the other, Mandakini, is the Hindi word for Milky Way). They published their findings in Astronomy and astrophysics.

A mature galaxy like ours has what’s called a “grand design” spiral, or two massive arms swirling outward from the center that astronomers have long believed required billions of years to accumulate enough material. Alaknanda seems to have achieved this feat in record time.

Read more: “Star siblings tell tales of galactic chaos”

“Alaknanda has the structural maturity that we associate with galaxies that are billions of years old,” Jain explained in a statement. “The discovery of such a well-organized spiral disk at this time tells us that the physical processes behind galaxy formation – gas accretion, disk sedimentation and possibly the development of spiral density waves – may operate much more efficiently than current models predict. This forces us to rethink our theoretical framework.”

It’s not just Alaknanda’s form that has raised eyebrows, but also his productivity. The early galaxy produces stars 20 times faster than the Milky Way, adding the equivalent of 60 suns each year. This discovery changes what we know about how galaxies evolve and sheds light on what the early universe was like.

“Alaknanda reveals that the early universe was capable of assembling galaxies much faster than previously thought,” Wadadekar said. “Somehow, this galaxy managed to gather 10 billion solar masses of stars and organize them into a magnificent spiral disk in just a few hundred million years. That’s extraordinarily fast by cosmic standards, and it’s forcing astronomers to rethink how galaxies form.”

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Main image: NASA/ESA/CSA, I. Labbe/R. Bezanson/Alyssa Pagan (STScI), Rashi Jain/Yogesh Wadadekar (NCRA-TIFR)

• Jake Currie

  Published on January 5, 2026

  Jake Currie is a writer based in Brooklyn, New York.