The first few billion years of Earth's history saw the rise of life, the atmosphere and the oceans. Still, that time is shrouded in mystery: Not many rocks remain that preserve a record of those early iterations of our modern world. Dynamic geologic processes like erosion, subduction and burial mean the surface is constantly being reshaped, and older rocks aren't very common. But that time period is critical to understanding our own origins and how catastrophic events like asteroid impacts might have affected early life on the planet. ...read more read less