Space Dust Shows Early Earth’s Atmosphere Was Rich In Oxygen
|A micrometeorite extracted from 2.7 billion-year-old limestone in Western Australia contains iron oxide that formed when iron metal oxidised upon entering the Earth’s atmosphere, indicating that the ancient upper atmosphere was surprisingly oxygen-rich. |
MELBOURNE, Australia – A recent study of the oldest micrometeorites known to exist shows that Earth’s ancient atmosphere was rich in oxygen, challenging the accepted view that Earth’s atmosphere was oxygen-poor billions of years ago.
By examining micrometeorites – space dust – that fell to Earth 2.7 billion years ago, researchers found that ancient Earth’s upper atmosphere during the Archean eon contained about the same amount of oxygen as today, and that a methane haze layer separated this oxygen-rich upper layer from the oxygen-starved lower atmosphere.
Scientists extracted the micrometeorites from samples of ancient limestone collected in the Pilbara region in Western Australia and later examined them at the Monash Centre for Electron Microscopy and the Australian Synchrotron.
- Cocoa Beach
- Jelly Fish