News Earth

Oxygen wafted into Earth’s atmosphere earlier than thought

Date pushed back to 3 billion years ago

RUSTY BELT  Red bands of oxidized iron run through ancient marine rocks in the Pongola river bed in South Africa.  Scientists used these and other rocks to determine oxygen was present in Earth’s atmosphere nearly 3 billion years.

Nicolas J. Beukes/Univ. of Johannesburg

By Jessica Shugart

- More than 2 years ago

The date of Earth’s first whiff of oxygen may have occurred 300 million to 400 million years earlier than scientists thought.