Astronomers announced Monday that traces of a rare molecule known as phosphine have been discovered in the infernal and extremely acidic atmosphere of Venus – providing bewildering evidence of the possibility of life. The phosphine molecules found on Earth are primarily the result of human industry or the actions of microbes that thrive in oxygen-free environments.

Researchers do not claim that life was discovered on the second planet from the sun. But the observations indicate at least the possibility of microbial activity in the upper layers of Venus’ atmosphere, far from the surface of the harsh planet.

“We have detected the presence of a rare gas called phosphine in the atmosphere of our neighboring planet Venus,” said Jane Graves, a professor at Cardiff University in the United Kingdom and lead author of a report published in the journal. Natural Astronomy. “The reason we are so excited is that phosphine gas on Earth is made from microorganisms that live in environments devoid of oxygen. Thus there is a chance that we discovered some kind of organism in the clouds of Venus.”

However, the team said, more study is needed to support any such claim, although it would be unusual.

“In order to make this absolutely extraordinary claim that there may be life out there, we really have to rule out everything, which is why we are very careful to say that we are not claiming that there is life, but that we claim that there is something really unknown.” Team member William Pines said, Researcher at the Massachusetts Institute of Technology: Life May Be.

Sarah Seager, a MIT scientist who studies exoplanet atmospheres, agreed, saying, “We are not claiming that we have found life on Venus.”

“We claim the confident discovery of phosphine, whose existence is a mystery,” she said. “Phosphine can be produced by some (non-biological) processes on Venus, but only in very small quantities that are not sufficient to explain our observation. So we are left with this other exciting and tempting possibility: maybe there is some kind of life in the clouds of Venus.”

Mars has long been considered the best candidate in the extraterrestrial solar system to host microbial life in the distant past or even the present, as suggested by methane levels in the background. NASA, the European Space Agency, China, India, Russia and the United Arab Emirates are all watching Explore the red planet one way or another.

NASA is also planning a major mission to study Moons of Jupiter. Scientists believe that one of the largest and most famous moons of the planet, EuropeHeated by tidal pressures and gravitational interactions with other moons, it harbors a salty ocean, possibly habitable under its icy crust. Other frozen moons of the outer solar system, potential “water worlds”, are also candidates for study.

But Venus is a victim of the unbridled greenhouse effect as dense clouds in the atmosphere trap mostly sunlight with carbon dioxide, resulting in surface temperatures of about 900 degrees that are hot enough to melt lead.

However, in the planet’s upper atmosphere, temperatures are more favorable. Despite the acidic nature of clouds, scientists have speculated that strange microbes may be present.

“Surface conditions out there today are really hostile, and the temperature is enough to melt our landers,” Graves said. “ But it is thought that very early in the history of Venus, the surface was cooler and wetter and maybe life arose.

“There is a long-standing theory that some of the smallest life forms may be able to evolve up to high clouds. The conditions there are certainly not pleasant, they are very acidic and the winds are strong, but on the other hand, if you are talking about 50 to 60 kilometers high, it would be The pressure is very similar to the Earth’s surface and the temperature is very gentle, maybe around 85 degrees Fahrenheit. So it has been assumed that this is the livelihood of today’s habitat. ”

Graves ‘team studied the spectra of Venus’ atmosphere using the James Clerk Maxwell Telescope in Hawaii and 45 radio telescope antennas in the Atacama Large Millimeter / Sub Array in Chile and were surprised to see clear signs of phosphine. “It was a shock,” said Graves.

The discovery was rewarded with additional observation time on the ALMA matrix and “in the end, we found that both observatories saw the same thing, weak absorption at the appropriate wavelength to be phosphine gas, with molecules illuminated from the back by the warmer clouds below,” Graves said in a statement.

Only trace amounts have been observed, around 20 molecules per billion. But additional research has shown that the natural sources of phosphine – volcanoes, lightning, exploding minerals in the atmosphere, the action of sunlight – will generate only one in ten thousand of the amount already discovered.

The team could rule out many non-biological methods of generating the observed levels of phosphine, but that doesn’t mean life is the only explanation. Kara Souza Silva, a researcher at the Massachusetts Institute of Technology, said that the atmosphere of Venus contains 90% sulfuric acid, which raises “many questions, such as how any living thing can live.”

“On Earth, some microbes can handle up to 5% of the acid in their environment, but Venus’ clouds are almost entirely made of acid,” she said.

The Greaves team is waiting for extra time for the telescope to look for signs of other gases associated with biological activity and to determine the temperature of clouds where the phosphine is present for additional insights. Ultimately, future visits to the spacecraft will likely be required to fully solve the problem.

“There can always be something that we overlook,” Seager said. “Ultimately, the only thing that will answer this question for us – is there life, there is no life – is actually going to Venus and making more detailed measurements of the signs of life and maybe life itself.”