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6 March 2014 1:04 pm ,
Vol. 343 ,
Magdalena Koziol, a former postdoc at Yale University, was the victim of scientific sabotage. Now, she is suing the...
Antiretroviral drugs can protect people from becoming infected by HIV. But so-called pre-exposure prophylaxis, or PrEP...
Two studies show that eating a diet low in protein and high in carbohydrates is linked to a longer, healthier life, and...
Considered an icon of conservation science, researchers at World Wildlife Fund (WWF) headquarters in Washington, D.C.,...
The new atlas, which shows the distribution of important trace metals and other substances, is the first product of...
Early in April, the first of a fleet of environmental monitoring satellites will lift off from Europe's spaceport in...
Since 2000, U.S. government health research agencies have spent almost $1 billion on an effort to churn out thousands...
- 6 March 2014 1:04 pm , Vol. 343 , #6175
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ScienceShot: An Atmospheric Flip-Flop
18 March 2012 2:00 pm
About 2.45 billion years ago, Earth might have been confused for Titan. Research published today in Nature Geoscience suggests that our planet had the same hazy, methane-rich atmosphere as Saturn's largest moon (pictured). Scientists analyzed 2.65-billion- to 2.5-billion-year-old sediments from South Africa in order to reconstruct past ocean and atmosphere chemistry. They were surprised to find that, rather than a single, consistent past atmospheric state, Earth flip-flopped between "organic haze," or hydrocarbon smog, and "haze-free" conditions. Methane-producing microbes in the ocean, the researchers say, drove these cycles. Some oxygen was being produced by other seafaring microbes, but little of it reached the atmosphere. It was not until about 100 million years later that photosynthetic organisms known as cyanobacteria dominated the seas and injected massive amounts of oxygen into the atmosphere, creating conditions similar to those we enjoy today.
See more ScienceShots.