The discovery of phosphine gas in Venus’s clouds has surprised scientists, who are now wrestling with a larger question: Could this be a sign of alien life?
New research published on Monday in the journal Nature Astronomy detailed the gas’s recent discovery as well as its possible origins. And while the scientists behind the research are yet to give any definitive conclusions, supernatural life is one of the few explanations that make sense.
“If this indication is true, then there is a process on Venus that we cannot explain that produces phosphine – and one hypothesis is that it is life in the clouds of Venus,” Janus Petkowski, an astronomer at the Massachusetts Institute of Technology Said who worked. On research. “It’s too far, until it isn’t.”
But no foreign visitors are expected yet. At best, the gas can be caused by microorganisms in Venus’s upper atmosphere, about 150 million miles away – the closest planet to Earth and practically the next gateway to astronomical terms.
Nevertheless, the discovery led to some surprises.
“I was really surprised,” said Clara Susa-Silva, a molecular astrophysicist at MIT, who has devoted much of her career to studying phosphine as a possible “biosignature” of the distant world. “I put all this work in search of phosphine everywhere, but here it was on our nearest neighbor.”
Researchers have unearthed all known chemical processes that may be responsible for the phosphine gas on Venus – even foreign causes such as volcanoes, lightning, and delivery by meteorites – but they have found nothing to explain it.
Here on Earth, phosphine comes from microorganisms that break down decaying plants and animals without oxygen. It is commonly found with associated gas dipoles, which have a fish rot-like odor.
This makes the potential for phosphine what scientists call a biosignature – a chemical signal that can be detected by a spectroscopic telescope that can signal the port of a planet in the least simple forms of life.
The discovery also sheds light on one main way astronomers hope to detect supernatural life – not from finding spacecraft or small green men, but by detecting its chemical signals in distant planetary atmospheres.
For example, at extreme temperatures and pressures inside gas giants like Jupiter and Saturn, there are few ways to chemically make phosphine – but there are no known ways to make it in the atmosphere of a stony planet like Venus, Petkowski said .
What they have found, however, is that the gas must be continuously produced for rapid breakdown in Venus’s atmosphere, and that it is found only in clouds near the equator, which would be expected if there were biological causes. is.
The search for alien life in our solar system has focused on Mars, which is a much smaller, colder rocky planet than the Sun than Earth. Methane gas has been detected in its atmosphere, which may be a sign of life – but methane is also known to have geological sources.
Venus, about the same size as the Earth, orbits near the Sun – but it is a scorched and inaccessible place with warm surface temperatures that melt lead and create an unbearable environment for humans filled with clouds of sulfuric acid goes.
Nevertheless, scientists speculate that microorganisms can survive in Venus’s clouds 30 to 40 miles above the surface, where it is cold enough for water – although this would be a highly acidic environment.
And this is exactly where traces of phosphine have now been found, and in relatively high concentrations, about 20 parts per billion – too much to be explained in any other way.
Phosphine gas was first detected on Venus in 2017, the lead author of the new study by Jane Greaves, an astronomer and astronomy professor at the University of Cardiff, Wales.
He saw his fingerprint in the spectrum of light collected from the Venusian clouds by the James Clerk Maxwell Telescope in Hawaii, and then confirmed it with the Alma Radio Telescope in the Atacama Desert of Chile in 2019.
Greaves explained that she was looking for phosphine on Venus primarily as a theoretical test, and the discovery was a “huge surprise”.
“I thought we would get a null result for some other astronomers, and didn’t waste a lot of telescope time,” she said.
Instead, his discovery now has scientists scrambling to explain it – and this can only be solved when a spacecraft eventually samples the Venusian atmosphere and tests it for life, he said .
“Chemical biosinciers are one of the primary tools we have for searching for life in the universe,” said Caleb Scharf, director of astronomy at Columbia University in New York, who was not involved in the study. “We can’t see aliens directly, but we may be able to ‘smell’ them.”
He said the discovery of phosphine in Venus’s atmosphere could be “super intriguing”. “It certainly looks like a potential biosignature.”
But he warned that this could be the result of unknown chemical processes, which are poorly understood on Venus.
“Until we get a better handle on that, it would be very difficult to say that this phosphine is definitely coming from living things,” he said.