Potential ‘life’ signs detected on Venus
Published: 02:37 PM, 15 September 2020
Venus Planet; Photo: Collected
Scientists said that the discovery of phosphine gas in the Venus clouds may indicate the “possible life” signs on the planet, suggesting the planet could not host unknown photochemical or geochemical processes.
Phosphine, on Earth, is a colorless gas that has the smell of garlic or decaying fish which is produced by anaerobic biological sources. Its small amount of gas naturally breaks its organic matter, reports Metro UK.
As the conditions on the surface of Venus, the second planet from the Sun, are hostile to life, the environment of its upper cloud deck, around 53-62km (33-38 miles) above the surface, is temperate.
However, the study, led by Jane Greaves and his colleagues from Cardiff University along with James Clerk Maxwell Telescope and the Atacama Large Array in 2017 and 2019 respectively, published in the Nature Academy said that the clouds on Venus is highly acidic where phosphine could be destroyed very easily in such conditions.
The group detected a special signature that unique to phosphine and estimated an abundance of 20 parts-per-billion of phosphine in the clouds of Venus.
The researchers said that the gas may have been produced, including from sources on the surface of the planet, micrometeorites, lightning, or chemical processes happening within the clouds, however, they were unable to determine the source of the trace quantities of phosphine.
Though the detection of phosphine is not robust evidence for microbial life which only indicates potentially unknown geological or chemical processes occurring on the planet, they argued, saying that “further observations” and modeling are needed to explore the origin of the gas in the planet’s atmosphere.
“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 wrote in the paper.
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, they added.
“This could be unknown photochemistry or geochemistry, or possibly life.”
The researchers continue, “Even if confirmed, we emphasize that the detection of PH3 is not robust evidence for life, only for anomalous and unexplained chemistry.”
“However, we have ruled out many chemical routes to PH3, with the most likely ones falling short by four to eight orders of magnitude,” they added.
Associate Professor Alan Duffy, an astronomer from Swinburne University and the lead scientist of The Royal Institution of Australia, said: “This is one of the most exciting signs of the possible presence of life beyond Earth I have ever seen, and certainly from the most surprising location I could imagine.”
“Our twin planet Venus is a hellish world,” he also said, adding that “the surface is hot enough to melt lead, the temperature drops as go higher into the clouds, becoming Earth-like in both temperature and pressure by an altitude of 50km, exactly where the phosphine was found.”
Source: Metro UK