Yahoo News Scientists Release Air Trapped 800 Million Years Ago
We all kind of take oxygen for granted. It's just there, making up 21 percent of the air we breathe. But it hasn't always been like that. If you go back more than about two and a half billion years in our planet's history, you'll find zero oxygen in the air. Prior to about a billion years ago, the air wouldn't have had enough oxygen to breathe. Somewhere in between then and now, the air got oxygenated enough that it could support animal life. The question is, how did that happen, and how fast?
Unfortunately, we can't go back in time to sample the oxygen content of prehistoric air. But now it looks like we won't have to, as scientists from Brock University have announced they've managed to collect samples of ancient air that was trapped in tiny rock bubbles. Their findings are reported in a paper published in the journal Geology.
The team of scientists led by Nigel Blamey found tiny bubbles of air from around 800 million years ago trapped in samples of halite, which is the rock version of table salt. The scientists crushed the samples, releasing the air, which they ran through a machine called a quadrupole mass spectrometer.
The mass spectrometer measured the oxygen content of the prehistoric air and found that the air 800 million years ago was about 10 percent oxygen. This was five times higher than previously thought. Prior theories have estimated that until about 500 million years ago the air was relatively oxygen-free. Now it appears that oxygen was much more abundant much further back in the timeline, and scientists are not sure why.
All the oxygen in the air 800 million years ago must have been produced by some sort of organism, and now scientists are on the hunt for it. If they can find it, it may dramatically change what we know of the Earth's history.
Source: Brock University via Motherboard
