IT SOUNDS like a hellish place: a barren, crater-strewn landscape covered in molten lava. But tantalising evidence from one of the world’s oldest surviving minerals suggests that this conventional picture of the early Earth is wrong: the planet was in fact relatively cool and wet, and may even have supported life.
“Geologists have tended to assume the first 500 million years were hot,” says geologist John Valley of the University of Wisconsin in Madison. The planet formed 4.6 billion years ago, but the oldest rocks on Earth are no older than 4 billion years old. That has led researchers to believe that, after spending about 100…
