Earth formed around 4.54 billion years ago. Knowing how old Earth is can be more difficult to confirm because Earth's age is not only based on the age of rocks, but also the isotopic estimates of what ...

Earth has never stood still. Over its 4.5 billion years of history, our planet has been reshaped by different cataclysms and climate shifts. The atmosphere went through several changes, oceans froze ...

Our species likes it cold. Homo sapiens evolved in — and still inhabits — one of Earth’s rare and fragile ice ages, periods distinguished not by an abundance of saber-toothed cats and woolly mammoths ...