The discovery of phosphine, a highly toxic gas, in Venus’ atmosphere has drawn the attention of alien life researchers to a planet seen rather as the counterexample of a life-friendly environment.
In a few hours, hypothetical Venusians came to supplant the traditional Martians in the media imagination. “Of life on Venus?” “Asks the New York Times, while the venerable Massachusetts Institute of Technology (MIT) news site states that” astronomers may have found a signature of the presence of life on Venus. “
This is due to a team of researchers from Cardiff University in the United Kingdom who observed traces of phosphine in the clouds of the second planet in the solar system. Their discovery, published in the journal Nature Astronomy Monday, September 14, was called “the most important event to date in the search for life outside the Earth”, by Jim Bridenstine, administrator of NASA.
Venus, hostile to life
What is the relationship between this extremely flammable gas, highly toxic to humans, and life? It is present on Earth as well as on other planets, such as Saturn or Jupiter, which however do not harbor any form of extraterrestrial life.
But the Venusian atmosphere is more like that of Earth where “the presence of phosphine is always associated with living things”, underlines Franck Montmessin, researcher at the Laboratory Atmospheres, Environments, Spatial Observations (Latmos) of the CNRS, contacted by France 24. He There are two types of atmosphere, explains this researcher: that of planets like Jupiter, whose “chemical processes are rather favorable to the subsistence of this gas”, and that of the Earth or Venus – called an oxidizing atmosphere -, which does not is not. In the latter case, the presence of phosphine on the surface is the result of biological activities. It must be expelled regularly by organisms to continue to remain perceptible in the atmosphere. On Earth, phosphine is also used in industry, such as in the manufacture of semiconductors.
The possible implications of the discovery of traces of this gas in the Venusian clouds took the scientific community all the more by surprise since this planet is not on the radars of alien life seekers. On the contrary: “We could cite it as a counter-example of what a living habitat could be”, even says Franck Montmessin. The atmosphere there is 95% carbon dioxide, which means that there is a surface temperature of over 450 ° C, while the clouds are made up of over 90% sulfuric acid, so highly toxic. Not to mention that the atmospheric pressure is about 100 times higher than on Earth.
“Venus is the most extreme example of what the Earth could eventually become because of global warming”, summarizes Franck Montmessin. It’s hard to imagine a more improbable place to locate the first signs of extraterrestrial life. Except to adhere to hypotheses developed in the 1960s by a handful of scientists, like the American biophysicist Harold Morowitz, who maintained that life could be possible in… the clouds of Venus.