It turns out that Venus’ clouds aren’t made of the right stuff to support life – so scientists are now heading to Jupiter instead.
Infernal temperatures on the surface of Venus can reach nearly 900 degrees Fahrenheit – creating an inhospitable planet. But theHopes renewed that Venus could support life after researchers discovered phosphine gas, which is produced by bacteria on Earth, in milder clouds.
Now, a new study, published Monday in Nature Astronomy, has found that the concentration of water in the infamous sulfuric acid clouds near our closest neighbors is too dry for life as we know it to find a way to survive.
Microbiologist John Hallsworth discovered a ground mushroom in 2017 that was able to survive at 58.5% relative humidity – the driest conditions an organism had ever withstood. He decided to test whether it could exist on other planets.
“We have leaned back to argue that the most extreme and enduring microbes on Earth could be active on Venus,” Hallsworth said at a press conference.
Hallsworth has not found any known organism that can survive in the atmosphere of our sister planet, which equates to a relative humidity of 0.4%. His team studied the planet’s “hydroactivity”, meaning the concentration of water molecules, not the actual amount of water, to come to their conclusion.
Water activity is calculated based on direct observations of pressure, temperature and water concentration. The researchers used current measurements from seven US and Soviet probes and one orbital mission from the late 1970s and early 1980s.
“It’s more than 100 times too low,” he said. “It’s almost at the bottom of the scale, at an insurmountable distance from what it takes life to be active.”
“The search for extraterrestrial life has at times been a bit simplistic in his attitude to water,” said co-author Philip Ball. “As our work shows, it is not enough to say that liquid water equates to habitability. We also have to think about how Earth-like organisms actually use it – showing us that we then have to ask how much water is actually available for those biological uses.”
The results came nearly a month after NASA announcedTo a hell-like planet, scheduled for launch between 2028 and 2030. One of these missions could help determine if Venus supported life billions of years ago.
“One mission will fly through the atmosphere and measure the trace of gases … which will tell us a lot about the evolutionary history of Venus and begin to address questions like how much of Venus’s atmosphere is, where it went, and what happened?” McKay said.
Could Jupiter support life?
Scientists may have ruled out alien life on Venus, but Jupiter is still promising.
Studying probes that have visited other planets, researchers have found that Jupiter’s clouds contain a sufficiently high concentration of water, and a viable temperature, for the existence of life – assuming other requirements, such as nutrients.
“The results were more optimistic,” co-author Chris McKay said. “There is at least a layer in Jupiter’s clouds where water requirements are being met.”
But it is much easier to rule out the presence of extraterrestrials on Venus than to prove that they could be on Jupiter.
“To show that this stratum is habitable, we have to face all the requirements of life and prove that they are all fulfilled,” McKay said.
He added that further exploration is needed to identify other factors, such as UV exposure and energy sources. But the research provides a promising basis for studying all other planets in the future.
“We’ve also done calculations for Mars and Earth and showed that these calculations can be made for planets outside our solar system,” Hallsworth said. “While our research does not claim that alien (germ-type) life exists on other planets in our solar system, it does show that if water activity and other conditions are correct, then such life can exist in the places we have.” “.