The color of Earth’s sky has changed over time due to the presence and activities of different life forms. Initially, the sky had a grayish-blue-green tint due to a nitrogen and carbon-dioxide-rich atmosphere with little oxygen. Methanogenic bacteria then turned the sky orange by producing methane, which formed hazes that absorbed blue light. Eventually, cyanobacteria produced oxygen, which cleared the haze and restored the sky to its current blue color.
Related Posts
Avian flu virus has been found in raw milk − a reminder of how pasteurization protects health
Pasteurizing milk kills disease-causing pathogens that dairy cattle pick up in fields and barns. steverts, iStock /Getty Images…
Listen to the Albert’s lyrebird: the best performer you’ve never heard of
Alberts lyrebird in its natural habitat. Justin Welbergen, CC BY-NC Fiona Backhouse, Western Sydney University; Anastasia Dalziell, University…
More than 200 scientists from 19 countries want to tell us the Southern Ocean is in trouble
Pat James, Australian Antarctic Division Andrew J Constable, University of Tasmania and Jess Melbourne-Thomas, CSIRO While the Southern…
Evolution At Our Fingertips
In a fascinating demonstration of evolution, bacteria exposed to increasing concentrations of antibiotics develop resistance rapidly. Within 11…