NASA Mariner 10 took this image of Venus’s cloud. Credit: NASA/JPL-CALTECH
A recent document suggests that if astrobiologists want to make an educated hypothesis on how life could appear on Venus, they should look at a strange microbus called A. FerroossidaniFound here onearth.
The earthly life forms are the only examples that we have of how life appears, so astrobiologists often study them for clues about how alien ones could evolve. If we want a good example of how life could appear on Venus, however, we must consider it how on that planet it can live in its atmosphere and not on the ground. But any life in the clouds of Venus should find a way to maintain his organels and mortal Venusian acids, while they survive almost without water.
Grzegorz Słowik, planetary scientist of Maria Curie-Skłodowska University in Poland, and his colleagues have recently presented a contender in the search for an analogous terrestrial for Venusian life: a bacterium called AciditchiBacillus ironoxidans. They published their work in November 2024 in International Journal of Astrobiology.
Related: Could the clouds of Venus support life?
An analogue of the earth for alien microbes
Some studies have offered attractive suggestions that alien life could be drifting in the clouds of Venus. There are some chemical imbalances difficult to explain in the atmosphere of the planet, which could suggest that life is influencing the chemistry of the planet (although these imbalances may not be thus pronounced as initially reported or attributable to life). And isolated stripes inside the layers of the lower cloud of the planet (between 30 and 32 miles [48–51 kilometers] Above the surface) absorb the ultraviolet light (UV) in the same wavelengths of some types of chlorophyll – and the way these stripes change size and shape during the Venusian year recalls some astrobiologists of sea algae blooms here on earth.
Life dispersed in the air is not a totally far -fetched idea: biologists have found bacteria floating in the terrestrial atmosphere at an altitude of 25 miles (41 km), more than three times higher than the commercial line planes. And the Venusian skies offer greater possibilities of survival than the ground. The Venus surface is an infernal landscape with temperatures of about 900 degrees Fahrenheit (485 degrees Celsius) and pressure 92 times greater than the surface of the earth. It is hot enough to dissolve the lead or pond, and heavy enough to crush a nuclear submarine. But a few dozens of miles above the surface, the temperatures are a sultry but technically livable 140 f (60 c) and reach about the same pressure as the sea level on earth.
No problem, except for the fact that Venus’s clouds are made of very concentrated sulfuric acid.
Enter A. FerroossidaniA deeply strange microbo that has evolved to live in extremely acidic environments. A. Ferroossidani It thrives in acid conditions as much soda, vinegar or lemon juice, but it was found surviving in environments with a pH comparable to the acid of the human stomach.
“The fact that A. Ferroossidani It thrives on pH starting from 1.3 suggests that it could potentially survive and even metabolize the inorganic sulfur compounds found in the clouds of Venus “, write Słowik and its colleagues in their document.
Meet acidophili
A. Ferroossidani It presents itself in rocks rich in sulfur and soil and toxic drainage waters full of uranium from the mines (in fact,, A. Ferroossidani seems to help Do Those toxic drainage waters dissolve the sulfur rich minerals). It gets energy by sneaking the iron and sulfur compounds, which makes it a life form called chemotrophic. More specifically, it is a chemolithoautotroph, an organism that survives by breaking down inorganic chemicals in rocks or soil or dust beans. (In this case, “inorganic” simply means molecules that do not contain carbon-hydrogen links.)
“Understand how chemotrofic organisms like A. Ferroossidani Metabolizing these compounds could give us a better understanding of Venus’s potential to support life – or how life may have evolved in the past, “says the Planetary scientist of Duke University Aleksandra Stryjska, co -author of the recent article, Astronomy. And understand how A. Ferroossidani Surviving in such painfully acidic conditions could shed light on how any form of life could survive in the clouds of sulfuric acid of Venus.
And there is another thing he does A. Ferroossidani So intriguing: it absorbs UV light in a very similar set of wavelengths to the atmosphere unknown in the atmosphere of Venus.
“This is intriguing because it has been hypothesized that the UV absorption function on Venus is due to a photosynthetic body,” says Stryjska. “If the UV absorbitor is really something similar A. FerroossidaniIt could indicate a form of life that uses chemical energy (such as compound of sulfur or iron) rather than sunlight, which adapts to the highly acidic environment rich in Venus’ energy. ”
Analogues aliens
Słowik and his colleagues are not suggesting that the colonies of A. Ferroossidani They are floating in the clouds of Venus. Instead, they argue that this microbo and other acidophili (microbes that live in acid environments) could offer clues to the types of traits that life could evolve to survive in such a hostile environment. Suggest that biologists should experience several strains of A. Ferroossidani In the laboratory, testing them in conditions more like Venus, until in the end they raise a tension that could survive there.
“If A. Ferroossidani If they survive Venus, it should probably be adapted to the high acidity, the lack of oxygen and the low levels of water available, “says Stryjska.
But the goal would not be to sow Venus with terrestrial life – just to see how Venusian life could be and what could make it appear.
“Understand how chemotrofic organisms like A. Ferroossidani metabolize [iron and sulfur] The compounds could give us a better understanding of Venus’s potential to support life – or how life may have evolved in the past, “says Stryjska.” How has the chemistry of Venus’s atmosphere evolved to support or inhibit life? Have you started with more habitable conditions or has it always been extreme? “
Study an analogue like A. Ferroossidani It could also give astrobiologists clues to how to recognize the chemical signatures of potential life in the atmosphere of Venus or another world – if it is there.
What if there was analogue?
“It is an open question if the clouds of Venus have the necessary conditions to support too [extreme] Life, “says Stryjska.
A key question, which will not be resolved without sending more space vehicles to study the Venusian atmosphere up close, is exactly how acid the clouds of the planet are. So far, no mission has measured these clouds directly; Instead, planetary scientists estimated the acidity of the clouds based on other measurements of their chemical makeup. But the planetary scientist of Mit Janusz Petkowski, who has not been involved in the recent study, says Astronomy That he and his team of researchers expect the clouds to be different orders of magnitude more acidic than any environment on earth – so acid to be measured on something called Hammett scale, which extends the family member of the pH.
On the pH scale, which ranges from 1 to 14, the water is a 7. Neutral stomach acid to 1. And on the Hammett scale, the Venusian clouds evaluate somewhere around -12, according to Petkowski’s calculations.
“Where we have very acidic conditions here on earth, it is always the water that dominates the chemistry of these tanks, not acidic. In the clouds of Venus, you have traces of water dissolved in an acid,” says Petkowski. “Concentrated sulfuric acid prevents any organism similar to the land of being there, because you should adapt to sulfuric acid as a solvent.”
In other words, life on Venus may have to use chemicals such as sulfuric acid in the same way in which life on earth uses water. And to fully understand it, the researchers may have to dream of alternative biochimestre in the laboratory.
Related: How to build aliens in the laboratory
Beyond the clouds
Independently, A. Ferroossidani It can offer some important suggestions on life on Venus and elsewhere, according to Stryjska.
“Since meteorites can contain organic compounds and possibly vital microbes, A. Ferroossidani It could be used to understand how life could survive the extreme conditions of the space travel – such as radiation, emptiness and temperature fluctuations – while incorporated into a meteorite “, says Stryjska. So, therefore,”A. Ferroossidani It could also be a similar one to study life in environments where chemical energy rather than solar energy is the primary energy source. ”
This could mean places such as hydrothermal air intakes on the bottom of the sea of Europe and underground ecosystems on Mars.
Of course, if we ever find life in these places, it has not yet been seen, but understanding how it could develop and survive is an important first step.
