Watch the Earth's tectonic plates grow, shrink, and jostle for position in this new model of the last billion years on the ...

Oxygen first accumulated in the Earth's atmosphere about 2.4 billion years ago, during the Great Oxidation Event. A long-standing puzzle has been that geologic clues suggest early bacteria were ...

700 million years ago, the Earth was almost entirely frozen, an episode called "Snowball Earth". Its titanic glaciers played ...