Billions of years ago, our planet did not have the deep blue oceans we admire today. Instead, they were actually […] ...

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.

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 ...