Possible marker of life spotted on venus

Astronomers have discovered a rare molecule -- phosphine -- in the clouds of Venus. On Earth, this gas is only made industrially or by microbes that thrive in oxygen-free environments. Astronomers have speculated for decades that high clouds on Venus could offer a home for microbes -- floating free of the scorching surface but needing to tolerate very high acidity. The detection of phosphine could point to such extra-terrestrial 'aerial' life.