Earth's oceans could one day turn purple. Nearly three fourths of Earth is covered by oceans, making the planet look like a pale blue dot from space. But Japanese researchers have made a compelling ...

Instead, they were a striking shade of green, shaped by ancient microbial life and the chemical composition of early seas. Now, scientists warn that Earth’s oceans may be shifting back to a ...

Instead, they were actually a striking shade of green due to the chemical composition of early seas and ancient microbial ...

Before plants ruled, Earth may have glowed violet. The first life forms used retinal instead of chlorophyll, absorbing green light and reflecting red and blue—turning the planet an eerie purple.