About 201 million years ago, at the close of a geological period called the Triassic, one of the worst mass extinctions in ...

Every breath a person takes draws from a gas mixture that has barely shifted in recorded history: roughly 78 percent nitrogen ...

Earth was mostly devoid of oxygen for much of its 4.5 billion year lifetime. That is, until certain processes started to ...

Today, oxygen takes up a hefty portion of Earth’s atmosphere: Life-sustaining O2 molecules make up 21 percent of the air we breathe. However, very early in Earth’s history, O2 was a rare — if not ...

Oxygen photosynthesis has to be the greatest giver of life on Earth, and researchers have cracked yet another part of its complex and efficient chemistry. The more we know about it, the better we may ...

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 ...