September 14, 2020

expert reaction to discovery of phosphine on Venus

A study, published in Nature Astronomy, reports the discovery of the gas phosphine in the atmosphere of Venus. 

Prof David Rothery, Professor of Planetary Geosciences at The Open University, said:

“Today’s announcement of the discovery of phosphine at Venus is not a demonstration that life exists in its clouds. The authors do not claim this, but there is a danger that some media will spin it that way.

“What the work does demonstrate it that there is phosphine gas in Venus’s atmosphere in a concentration that, although low (about 20 parts per billion), is too high to be simply explained. Phosphine should not survive long among the acid and ultraviolet-bathed clouds. However it could be produced by microbes suspended in the air, in the ‘sweet zone’ 50-60 km up where the temperature is cool enough for life, at a rate sufficient to match its rate of inorganic decomposition. The planet’s surface, at about 460 degrees C, has been far too hot for life for well over a billion years, and the high atmosphere is probably the only place where life that began in the planet’s vanished oceans could now be hanging on. If explosive volcanic eruptions continue today, which is beginning to seem plausible, this would provide a ready way to supply nutrients – because even microbes cannot be expected to survive on ‘fresh’ air alone.”

https://www.nature.com/articles/s41550-020-1174-4

Declared Interests

David Rothery  “I played no part in the study referred to.”