New research led by Queen’s University Belfast argues that life could exist in the clouds of Jupiter, but not Venus.
The association of water and life is an ancient one. The molecule has played such a monumental role in the development of Earth’s organisms, and its presence could signal the possibility of life elsewhere in our universe.
However, a research team led by a Queen’s University Belfast scientist has published a paper suggesting that it isn’t the quantity of water on other planets that is important, but how the water is distributed.
The effective concentration of water molecules, known as ‘water activity’, is the measure of the relative availability of water. By computing the water activity of Venus and other planets from observations of temperature and water-vapour abundance, the team has offered new predictions pertaining to life in our solar system.
In a study published to Nature Astronomy, researchers examined the sulphuric acid clouds of Venus and found that the water activity was more than a hundred times below the lower limit at which life can exist on Earth.
But they also showed that Jupiter’s clouds have a high enough concentration of water, as well as the correct temperature, for life to exist there.
The research is contributing to ongoing discussions around the potential for life on Venus.
Last year, the molecule phosphine was reported in the clouds of Venus, which can be an indicator of microbial life. Following its discovery, then-NASA administrator Jim Bridenstine said it could be “the most significant development yet in building the case for life off Earth”.
However, other research claimed that the readings were misinterpreted and the molecule was more likely sulphur dioxide.
“Our research shows that the sulphuric acid clouds in Venus have too little water for active life to exist, based on what we know of life on Earth,” said Dr John E Hallsworth of Queen’s University Belfast, who was the research lead on the new water activity paper.
“We have also found that the conditions of water and temperature within Jupiter’s clouds could allow microbial-type life to subsist, assuming that other requirements such as nutrients are present.”
Hallsworth described the finding as “timely” given that NASA and the European Space Agency have renewed interest in Venus, with three missions planned in the coming years. He stated that one of these missions will take measurements that will be compared with the findings of his group, providing additional insights.
“While our research doesn’t claim that alien (microbial-type) life does exist on other planets in our solar system, it shows that if the water activity and other conditions are right, then such life could exist in places where we haven’t previously been looking,” Hallsworth added.