New observations of a chemical compound in Venus’ clouds have renewed interest in the possibility of life on our planetary neighbour
Almost three years ago, a team of scientists led by the Cardiff University astronomer Jane Greaves reported that they had discovered phosphine in the clouds surrounding Venus, our closest neighbour in the solar system. This was a big deal, because phosphine is a chemical compound that – here on Earth – is produced by microorganisms as they digest organic matter. As such, the scientists believed that its detection on Venus could signify the presence of alien life on the “hellscape” of the planet’s super-hot, rocky surface, or higher up in the atmosphere, where temperatures are cooler.
Naturally, a flurry of experiments were conducted in an attempt to confirm the findings, but the results didn’t look too promising. Some researchers suggested that Greaves’ team had mistakenly interpreted their radio telescope observations, seeing phosphine where there was actually just sulphur (a chemical element that is not considered a sign of life). Follow-up observations by NASA’s SOFIA also found no evidence of phosphine in Venus’ atmosphere.
Last week, though, Greaves delivered some potentially groundbreaking news at the Royal Astronomical Society’s National Astronomy Meeting in Cardiff. Using Hawaii’s James Clerk Maxwell Telescope (JCMT), her team has spotted phosphine deeper in the atmosphere of Venus than before, in the middle of the planet’s stinky, acidic clouds. Based on their observations, they think that the chemical could be coming from somewhere lower in the atmosphere.
Does this mean that alien life actually exists in this harsh, extraterrestrial environment, where surface temperatures are hot enough to melt lead? Well, Greaves was hesitant to make any concrete predictions (which could kick off a similar commotion to her 2020 announcement) and noted that other, undiscovered non-biological processes could be producing the gas. However, she also suggested that the renewed findings should make the search for biomarkers on Venus a priority.
Unfortunately, the James Webb Space Telescope – which is uniquely capable of detecting signs of life in other planets’ atmospheres – is too sensitive to train its gaze on any object so close to the sun. Fortunately, several Venus-bound missions are lined up to launch in 2030, including NASA’s VERITAS (which aims to map the Venusian surface from orbit) and another orbiter, ESA’s EnVision (which will scan Venus from its inner core to its upper atmosphere). In 2031, meanwhile, the NASA lander DAVINCI+ will undertake a suicidal mission to the surface of Venus, gathering crucial data about the atmosphere during its hour-long descent.
Hopefully, all of these missions will help shed some light on what’s producing the potential biomarkers in the atmosphere of the second planet from the sun. In the meantime, observations are scheduled to continue via the JCMT.