A new study recently dismissed the long-time belief that life may exist in the clouds of Venus. This research claims explicitly that sulfur's unusual behavior in the atmosphere cannot be explained by an "aerial" form of extraterrestrials.
As specified in a Mail Online report, any life form in adequate abundance is expected to leave chemical fingerprints on a planet's atmosphere as it "consumes food and expels waste."
However, scientists at Cambridge University discovered no evidence of this after using biochemistry and atmospheric chemistry to test the hypothesis of "life in the clouds."
For decades, astronomers have speculated that sulfur in the clouds of the second planet from the sun may be able to support life and function as a potential food source.
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The SDO satellite captured an ultra-high-definition image of the Transit of Venus across the face of the sun on June 6, 2012, from space.
Abundance of Sulfur Oxide
Researchers said "aerial" life could not explain, though, the make-up of the atmosphere of Venus, not to mention the reason sulfur is sucked out of the air.
According to Sean Jordan from the Institute of Astronomy of Cambridge, they wanted life to be a potential explanation, yet when they ran the models, it was not a plausible solution.
In addition, the researchers' models looked at a specific feature of the dense atmosphere: the abundance of sulfur dioxide or SO2.
In the study published in Nature Communications, the scientists said that on Venus, the brightest natural object in the night sky of Earth after the moon, there are high SO2 levels lower in the clouds.
However, it somehow gets "sucked out" of the atmosphere "at higher altitudes," they added. On Earth, SO2 in the atmosphere comes from volcanic emissions.
Why SO2 Levels on Venus Decrease a Lot
The study's co-author, Cambridge's Department of Earth Sciences and Institute of Astronomy's Dr. Oliver Shorttle, said that if life is present, it must be impacting atmospheric chemistry.
As indicated in a similar ScienceAlert report, researchers used a combination of biochemical and atmospheric models to investigate the chemical reactions expected to take place, given the known sources of chemical energy in the atmosphere of Venus.
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The models included a list of metabolic reactions that the life forms would perform to get their "food" and the waste by-products.
Sulfur-Based 'Food' in the Venusian Atmosphere
The researchers ran the model to determine if such metabolic reactions could explain the reduced SO2 levels.
They discovered that the reactions could lead to a decline in SO2 levels, but only by generating other molecules in very large amounts that are unseen.
The outcomes set a hard limit on how much life could exist on Venus, minus blowing apart the scientists' understanding of how chemical reactions work in planetary atmospheres.
Jordan explained that they looked at the sulfur-based "food" available in the atmosphere of Venus; it is not anything "you or I" would want to consume, although it is the main available energy source.
If that food is being eaten by life, he elaborated, "we should see evidence of that" through particular chemicals being lost and gained in the atmosphere.
If life were accountable for the SO2 level seen on Venus, it would also break everything that's known about the atmospheric chemistry of Venus.
Related information about signs of life in Venus is shown on TheSimplySpace's YouTube video below:
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