The best evidence for life beyond Earth has been found in the most surprising of places – the atmosphere of Venus.
A team led by Jane Greaves, who is a professor at Cardiff University, has detected the presence of phosphine gas in Venus’ clouds. The intriguing thing about phosphine, which is a molecule formed of three hydrogen atoms and one phosphorous atom, is that on Earth its only natural source is from some anaerobic (i.e., non-oxygen breathing) microbial lifeforms.
No known geological mechanism or non-biological chemical reaction produces it on our planet, although it is produced deep inside gas giants like Jupiter and Saturn where hydrogen is plentiful and the temperature and pressure extremely high.
This was an experiment made out of pure curiosity, really,” says Greaves. “I thought we’d be able to rule out extreme scenarios, like the clouds being stuffed full of organisms. When we got the first hints of phosphine in Venus’ spectrum, it was a shock.”