Scientists surprised the world last yearear claiming to have discovered traces of phosphine in the Venusian clouds. New research suggests this gas, which, excitingly, is produced by microbes“He wasn’t really responsible for the signal they detected.” Instead, it was probably sulfur dioxide, an unexciting chemical.
Extraordinary research published in Nature last September is being challenged by a paper to be published in The Astrophysical Journal, a prepress of which is currently in available in the archive. This is not the first document critic the apparent discovery of phosphine on Venus and will probably not be the last.
That phosphine may be present on Venus was a revelation that made us explode, and this is because living organisms are one of the only known sources of stinking gas. The team responsible for the apparent discovery, led by Cardiff University astronomer Jane Greaves, found evidence in spectral signals collected by two radio dishes: the James Clerk Maxwell Telescope (JCMT) and the Atacama Large Millimeter / submillimeter Array (ALMA). Spectral lines at certain wavelengths indicate the presence of specific chemicals and, in this case, imply the presence of phosphine in the Venusian cloud layer.
The authors of the Nature study did not claim that life existed on Venus. Rather, they asked the scientific community to explain their rather strange observation. In fact, it was an exceptional statement, as it implied that Venus — one of the most inhospitable planets in the solar system — could be truly habitable, with microscopic organisms floating between the clouds.
Unfortunately, that doesn’t seem to be the case.
“Instead of phosphine in the clouds of Venus, the data are consistent with an alternative hypothesis: they detected sulfur dioxide,” says Victoria Meadows, co-author of the new study and professor of astronomy at the University of Washington. statement. “Sulfur dioxide is the third most common chemical compound in the atmosphere of Venus and is not considered a sign of life.”
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Meadows, along with researchers from NASA, the Georgia Institute of Technology, and the University of California at Riverside, came to this conclusion by modeling the conditions of the Venusian atmosphere, which they did to reinterpret the radio data collected by Riverside. the original equipment.
“This is what is known as a radiative transfer model, and it incorporates data from Venus observations from several decades from various sources, including observatories here on Earth and spacecraft missions like Venus Express,” explained Andrew Lincowski, UW Department of Astronomy researcher and lead author of the paper, in the statement.
Equipped with the model, the researchers simulated spectral lines produced by phosphine and sulfur at multiple atmospheric altitudes of Venus, as well as how they received these ALMA and JCMT signatures. The results showed that the shape of the signal, detected at 266.94 GHz, probably came from the Venusian mesosphere, an extreme altitude where sulfur dioxide may exist, but phosphine cannot do so due to harsh conditions. , according to research. In fact, this environment is so extreme that phosphine would not last more than a few seconds.
As the authors argue, the original researchers underestimated the amount of sulfur dioxide in the Venusian atmosphere and attributed the 266.94 GHz signal to phosphine (both phosphine and sulfur dioxide absorb radio waves. around this frequency). According to the researchers, this happened because of an “undesirable side effect” known as dilution of the spectral line, explained study co-author and NASA JPL scientist Alex Akins.
“They inferred a low detection of sulfur dioxide due to [an] ALMA’s artificially weak signal, ”Lincowski added. “But our modeling suggests that line-diluted ALMA data would have been consistent with typical amounts or even large amounts of Venus sulfur dioxide, which could fully explain the observed JCMT signal.”
This new result can be devastating for the document Nature and it will be interesting to know how the authors respond to this latest criticism. That said, some scientists believe the writing is already on the wall or, more accurately, in the trash.
“Already shortly after the publication of the original work, we and others have raised great doubts about its analysis,” Ignas Snellen, a professor at Leiden University, wrote in an email. “Now, personally, I think this is the last key in the coffin of the phosphine hypothesis. Of course, Venus can never be shown to be completely free of phosphine, but at least now there is no evidence to the contrary. I’m sure others will keep watching. “
In December, Snellen and colleagues challenged Nature’s study, arguing that the method used by Greaves’ team resulted in a high signal-to-noise ratio “spurious” and that there is no “statistical evidence. “about phosphine in Venus.
The apparent absence of phosphine in Venus, and therefore the absence of any indication of microbial life, is far less interesting than the opposite, but it is so at times. Science makes no claims or promises about the interestingness of all things, and we, as advocates of the scientific method, must accept our developing universe as we find it.