Scientists discover that the Atlantic Ocean was once a vast low-oxygen zone that was caused by geography, not a warming ...

In nutrient-rich lakes, that oxygen-free share of the season is projected to climb from about 40 to roughly 60 percent. Field ...

Earth was mostly devoid of oxygen for much of its 4.5 billion year lifetime. That is, until certain processes started to allow for the eventual buildup of oxygen up to the levels we have now (around ...

Earth's atmosphere wasn't always full of life-giving oxygen — it was once a choking mixture of carbon dioxide and other gases, more like the atmosphere of Mars or Venus. It's widely believed that the ...

After more than six years sniffing the red planet’s thin, frigid air, a NASA rover has made a startling discovery: There’s more oxygen gas in the Martian atmosphere than scientists expected, and ...