Astronomers using the James Webb Space Telescope (JWST) have uncovered compelling evidence that the Universe’s earliest galaxies were far more chaotic and unstable than previously believed. The findings, published in the Monthly Notices of the Royal Astronomical Society, challenge long-standing theories about galactic formation and offer new insights into the turbulent infancy of the cosmos.
Led by researchers from the University of Cambridge’s Kavli Institute for Cosmology, the study analyzed over 250 galaxies that formed between 800 million and 1.5 billion years after the Big Bang. Contrary to earlier models that suggested early galaxies quickly settled into smooth, rotating disks, the Webb data reveals that most were clumpy, gas-rich systems undergoing rapid star formation and frequent mergers.
Using JWST’s advanced infrared instruments, the team was able to chart the movement of gas within these galaxies with unprecedented precision. The results showed widespread turbulence, irregular structures, and signs of intense gravitational interactions. These chaotic conditions suggest that early galaxies were still in the throes of assembly, with their shapes and dynamics constantly reshaped by collisions and inflows of material.
Lead author Lola Danhaive noted that the findings bridge a critical gap in our understanding of galactic evolution. “We’re seeing galaxies in their formative years, still struggling to settle into the orderly structures we observe in the modern Universe,” she said. The study also helps explain the transition from this early chaos to the so-called “cosmic noon” period, roughly 2–3 billion years after the Big Bang, when star formation peaked and galaxies began to stabilize.
The Webb Telescope’s ability to peer deep into cosmic history has proven instrumental in reshaping our view of the Universe’s origins. These latest observations underscore the dynamic and violent processes that governed the birth of galaxies, offering a more nuanced picture of how the cosmos evolved from primordial disorder into the structured beauty we see today.
