# New Study Challenges Origins of the Universe's Epoch of Reionization Supernova-driven winds may have hindered rather than enabled the clearing of cosmic fog. - **Source:** [Latest from Live Science](https://www.livescience.com/feeds.xml) - **Published:** 2026-10-31 - **Topic:** [Business](https://brifing.si/c/business) - **Original article:** - **On Brifing:** https://brifing.si/s/42661500-9968-4937-9cc7-4aeea246638b ## Revisiting Cosmic History A recent study published in Nature Astronomy challenges long-held assumptions regarding the Epoch of Reionization. Researchers suggest that the mechanism clearing the universe's primordial hydrogen fog was not driven by supernovas as previously theorized. This finding necessitates a significant rethink of how the early universe transitioned into the transparent state observed today. ## The Role of Neutral Hydrogen Approximately 400,000 years after the Big Bang, the universe was filled with neutral hydrogen atoms, creating an opaque fog. This state prevented ultraviolet light from traveling through space. The Epoch of Reionization describes the subsequent phase where radiation ionized this gas, allowing light to finally propagate and reach modern observatories. ## Challenging Supernova Models Astrophysicists previously believed that violent supernovas, involving stars eight to 50 times the sun's mass, were responsible for dispersing this fog. However, the new research indicates these explosions actually trapped ionizing radiation. The study shows that galaxies with the fastest supernova-driven winds allowed the least amount of ultraviolet light to escape. ## Observing Local Analogues Cody Carr and his team utilized the Hubble Space Telescope to analyze six star-forming galaxies located 3.5 billion light-years away. These compact galaxies, which form stars at rates significantly higher than the Milky Way, served as proxies for the ancient universe. Their light-based spectra provided crucial data on stellar wind composition and speed. ## The Two-Phase Mechanism The study identified a counterintuitive two-phase process within these galaxies. During the first 3 million years, stellar winds from massive stars successfully carved paths for ionizing radiation. However, as these stars died in supernovas, the resulting galactic winds added opaque gas and dust, effectively trapping the Lyman continuum photons instead of scattering them. ## Discrepancies With Simulations These empirical findings directly contradict most current cosmological simulations, which typically predict that the escape fraction of ionizing radiation peaks following supernova-driven winds. By demonstrating that supernovas may dampen rather than drive reionization, the research highlights a critical gap in our understanding of how the early universe evolved into its current form. ## New Focus on Newborn Stars The study suggests that the intense radiation emitted by newborn stars is a more viable driver for the Epoch of Reionization than previously assumed. By shifting the focus away from supernova-driven winds, astronomers are now re-evaluating the primary sources of the ionizing energy that cleared the cosmic fog during the universe's infancy. ## Future Research Directions Moving forward, researchers aim to expand their sample size of galaxies to confirm these findings across different cosmic environments. Future observations will likely require higher-resolution data across various wavelengths to refine models of galaxy evolution. This ongoing work remains essential for mapping the complex transition periods that defined the early, unexplored universe. ## Sources covering this story - https://www.livescience.com/space/astronomy/astronomers-may-have-been-wrong-about-what-ended-the-cosmic-dark-age-new-study-hints — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._