Like cosmic toddlers, galaxies in the young universe were messy and struggled to settle down, a new study by James Webb shows.
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Using the powerful JWST Space Telescope, scientists examined more than 250 galaxies in the early universe. The research team mapped the motion of gas long ago, when the universe was growing — between 800 million and 1.5 billion years after the Big Bang. (The universe is about 13.8 billion years old.)
Their findings , published Tuesday (October 21) in the journal Monthly Notices of the Royal Astronomical Society, show that galaxies were restless in their youth.
Unlike previous studies, Lola Danhaive, the team targeted lower-mass galaxies and revealed what they called “messy kinematics,” meaning that the galaxies the researchers studied are not stable, rotating disks like the Milky Way and its neighbors.
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Turbulence during earlier phases of the universe's history was much higher than scientists previously thought, Danhaive added, because previous studies were biased toward larger and more ordered galaxies, which are easier to spot in telescopes than the smaller galaxies targeted by the new study.
In addition, the researchers documented how the galaxies changed from these chaotic structures to the more regular patterns observed in mature galaxies, providing an unprecedented insight into how galaxies grew from their youth to maturity.
Structures like the Milky Way formed more recently, over the past billions of years, as the available gas was absorbed by stars and reduced overall in the galaxy. Less freely floating gas allows mature galaxies to grow and change more smoothly than in younger times.
See also: James Webb "illuminates" star birth in the heart of the Milky Way
The study wouldn't be possible without the JWST, which is located in a distant, gravitationally stable spot in space, far from the scattered light of Earth and the Moon. The infrared telescope can probe deeper into space than any of its predecessors and is discovering galaxies that are believed to be the first in the known universe. Danhaive said the observatory, combined with simulations, is helping researchers better understand "explosive" star formation and how gas affects a galaxy's disk.
