Early Earth was a hellscape of molten lava and barren rock, bombarded by meteors, with no atmosphere at all. How did our familiar blue sky - the thin, life-giving band of gasses protecting our planet - come to be?

Explore the science behind the headlines in PBS’ premier science series. With compelling stories and spectacular visuals, NOVA programs demystify science and technology for viewers of all ages and spotlight people involved in scientific pursuits.