The Hadean Atmosphere Explained: What Earth’s First Sky Was Really Like
If you stepped outside on Earth 4.5 billion years ago, you would not survive one single breath. The atmosphere during the Hadean eon was not blue, not breathable, and not friendly. It was a thick, scorching, orange haze made of steam, carbon dioxide, and volcanic fumes, sitting on top of an ocean of melted rock. There was no sky as we know it. There was no oxygen. There was, in fact, almost nothing that resembled the planet you are reading this on right now.

