Primordial Chill Hints at Dark Matter Interactions in Early Universe A simple experiment has detected a signal from the first stars forming just 180 million years after the Big Bang. The observations have intriguing implications for the nature of dark matter. The first stars began to shine just 180 million years after the Big Bang , according to new observations by a team of American radio astronomers. The evidence comes from observations of neutral hydrogen gas that pervaded the early universe. But surprisingly, the same observations show an unexpected chill in this gas — a result that could hint at non-gravitational interactions with dark matter . “This is a really cool result,” says Michiel Brentjens (Netherlands Institute for Radio Astronomy), who was not involved in the study. “It’s an important first step in revealing how the very early universe behaved.” For years, astronomers like Brentjens have been trying to detect the early universe’s