The First Elements: What Helium Reveals About the Early Universe

How can scientists test what happened moments after the Big Bang? By studying distant, metal-poor galaxies, researchers measured primordial helium at approximately 24.58% of the early universe’s mass, closely matching predictions from cosmic microwave background observations. Comparisons with modern measurements also suggest that stars have produced around 10% of today’s cosmic helium, offering new insights into how the universe evolved from its earliest moments. Thank you for listening to Bedtime Astronomy — your guide to the cosmos. New episodes on space exploration, NASA missions & the latest astronomy breakthroughs. This episode includes AI-generated content.