For most of human history, Earth has been known as the “Pale Blue Dot,” a term popularized by astronomer Carl Sagan when referring to the iconic 1990 image taken by Voyager 1. But for billions of ...

Although the Earth’s been decidedly blue for 600 million years, rising populations of phytoplankton caused by rising ...

Paleontologist Riley Black traces the cooperation among plants, animals, and ecosystems in “When the Earth Was Green.” ...

A team of astrophysicists, geoscientists, chemists and life scientists affiliated with a host of institutions in Japan has found evidence that billions of years ago, the Earth's oceans were green.

For a long stretch of Earth’s history, our planet might have looked green from a distance, instead of the pale blue dot we know today. Earth’s green period, which lasted from around 3 billion ...