628872 external_news 1573501569 1573501569 For much of its existence, Earth has been inhabited. But if researchers remotely analyzed the atmosphere of that young Earth, they might have missed the evidence for life....In a 2017 paper led by Chris Reinhard at Georgia Tech, the Alternative Earths team flagged the danger of false negatives in the hunt for habitable planets. The presence of both methane and oxygen in an atmosphere has been viewed as a gold standard in the search for distant life. These two gases should not coexist in appreciable amounts, as they react rapidly with each other, but living organisms can constantly replenish them in the atmosphere, allowing this disequilibrium to persist.

]]> 2019-11-09 1278 364801