The early Earth was a vision of hell, all scalding rock and choking fumes. Since then, its surface has cooled, continents have drifted, mountains have risen and eroded, and life has emerged, benign and green. Nearly all traces of the planet as it was have been wiped away. But from clues in the oldest rocks, deepest magmas, and even the cratered face of the moon, scientists have traced the planet’s beginnings. As those early days have come into focus, so have the rare scenes, found today in some of Earth’s harshest places, that recall its ancient self.