Although the Earth’s been decidedly blue for 600 million years, rising populations of phytoplankton caused by rising temperatures are once again causing the world’s oceans to turn green.

Fossils and genetics are starting to point to life emerging surprisingly soon after Earth formed, when the planet was ...

From the beginning of time to the origins of life, our "when" special series tackles the timing of crucial events and the ...

For decades, scientists assumed that life on Earth emerged through a chain of highly improbable flukes. But a new theory suggests it may have instead arrived just in time.