Astronomers May Have Misidentified What Ended the Cosmic Dark Ages

For years, astronomers believed that the first galaxies were responsible for clearing the opaque hydrogen fog that shrouded the early universe, a period known as the Cosmic Dark Ages. New research suggests that the culprit might be something else entirely: black holes. The study, published in the journal Nature, used data from the James Webb Space Telescope to observe dwarf galaxies that existed just 500 million years after the Big Bang. These galaxies are too faint to produce enough ionizing radiation to reionize the universe, but they may host intermediate-mass black holes that could do the job. The findings challenge the long-held assumption that stars alone ended the Dark Ages. If black holes played a major role, it could reshape our understanding of how the universe evolved and how supermassive black holes formed. The next step is to observe more of these early galaxies to confirm the presence of black holes and measure their contribution to reionization.