Phosphine gas has been discovered in the clouds of Venus with scientists saying that this could possibly indicate signs of life on the planet. Detected in the atmosphere of Venus, the gas could suggest that the planet could host unknown photochemical or geochemical processes.
On Earth, this gas, which has the smell of garlic or (sorry) decaying fish, is predominantly produced by anaerobic biological sources.
Small amounts of the gas occur naturally from the breakdown of organic matter. The condition on the surface of Venus are hostile to life, with extremely high temperatures. However, the environment of its upper cloud deck, some 53-62km above the surface are temperate.
According to the study which was published in Nature Astronomy, the make-up of the clouds is highly acidic, in which case phosphine would be destroyed very quickly.
We have detected a gas called "phosphine" in the atmosphere of Venus, says @jgreaves6. This could point to the presence of life in the clouds of Venus. Their study is published in the journal Nature Astronomy and will be free to access today. #VenusNews
— Royal Astronomical Society (@RoyalAstroSoc) September 14, 2020
Jane Greaves, from Cardiff University, and her colleagues observed Venus with the James Clerk Maxwell Telescope and the Atacama Large Millimeter/submillimeter Array in 2017 and 2019, respectively.
They detected a spectral signature that is unique to phosphine, and estimated an abundance of 20 parts-per-billion of phosphine in Venus’s clouds.
They were unable to determine the source of the trace quantities of phosphine, however, they argue that the detection of phosphine is not robust evidence for microbial life, and it only indicated potentially unknown geological and/or chemical processes taking place on the planet. Which is why they say that further observations are needed to explore the origin of the gas, in the planet’s atmosphere.
Writing in the paper, they say: ‘PH3 (phosphine) could originate from unknown photochemistry or geochemistry, or, by analogy with biological production of PH3 on Earth, from the presence of life.”
They add: ‘If no known chemical process can explain PH3 within the upper atmosphere of Venus, then it must be produced by a process not previously considered plausible for Venusian conditions.
‘This could be unknown photochemistry or geochemistry, or possibly life.’
Professor Alan Duffy, an astronomer from Swinburne University said that this is one of the most exciting signs of the possible presence of life beyond Earth, that he has ever seen.
‘Our twin planet Venus is a hellish world. While the surface is hot enough to melt lead, the temperature drops as you go higher into the clouds, becoming Earth-like in both temperature and pressure by an altitude of 50km, exactly where the phosphine was found.