Last year, in the atmosphere of this Earth-like planet – Venus, it was found that molecules could be made of life forms – once considered a sign of life. But new research seems to dash human hopes for the existence of life on Venus.
This new study analyzes measurements taken by a probe that flies through Venus’s atmosphere and collects data on temperature, humidity and pressure in the dense sulfuric acid cloud surrounding Venus. Based on these data, the scientists were able to calculate that “water activity”, i.e. water pressure at the level of a single molecule in the cloud, is one of the factors limiting its existence. of life on Earth.
“By observing the effective concentrations of water molecules in these clouds, we found that even the most powerful living things on Earth could not survive here because of the high concentration of water in these clouds. the concentration of water molecules on this planet is only one percent of the concentration of water they need to survive“, John Hallsworth, a microbiologist at Queen’s University Belfast, UK, said in a press conference.This is a great distance that life cannot cross“.
These findings may disappoint researchers of Venus. Last September, they discovered phosphine in the atmosphere of Venus. This is a compound composed of phosphorus and hydrogen atoms, which can be associated with life forms on Earth. They were extremely excited by this discovery. At the time, researchers believed that phosphine might have been made by microorganisms living in the planet’s clouds.
On Earth, microorganisms can survive and multiply in water droplets in the atmosphere at the right temperature, says Holsworth. However, based on data from multiple Venus probes, this new study finds that the possibility of living things in the clouds of Venus is zero.
Holsworth adds: “Living systems, including microorganisms, are composed primarily of water. Without hydration, they cannot function and cannot reproduce. Research on microorganisms living in extreme conditions on Earth shows that life can survive at minus 40 degrees Celsius. For water activity (between 0 and 1), the threshold for viability is The lowest residual is 0.585. Meanwhile, the water activity of molecules in the clouds on Venus is only 0.004 ..”
One of the study’s co-authors, Chris McKay, an astrobiologist at NASA’s Ames Research Center, said at the press conference that the discovery is decisive and is currently in the process of being validated. for future research and it will show everyone that there is absolutely no possibility of life on Venus.
“Our conclusions are based on direct findings“, McKay said in a press conference.This is not a model or a hypothesis. NASA’s upcoming mission is to set foot on Venus and make the same measurements again, such as measuring temperature and pressure, which will certainly draw conclusions very similar to the study of NASA. us, because Venus will not change in this time scale. “
However, the researchers also analyzed data from other planets and found that water activity in Jupiter’s clouds is theoretically sufficient to support the existence of life. The Galileo probe, located about 42 to 68 km from the gas giant’s surface, also showed a water activity in the observed area of Jupiter of 0.585, the temperature in this area is also within the possible threshold survived, around minus 40 degrees Celsius.
McKay said:The possibility of life on Jupiter seems much more optimistic than on Venus. There is at least one layer in Jupiter’s cloud that can meet the need for water life. This does not mean that there is life there, it just means that it is suitable for life in terms of water activity.“.
However, the researchers say intense UV radiation or nutritional deficiencies can inhibit the potential of life to develop. We need new measurements to determine if life is really possible. Hallsworth added that the technology used to calculate water activity could also help determine the habitability of other planets.
Hallsworth said: “What excites me most is that our study of these distant planets can go down to the molecular scale of water and determine their habitability based on this.“.