New York: The detection of phosphine—a colourless, flammable gas—on the clouds of Venus, has kicked off an intense debate over the presence of life on the planet.
The find could be a sign of life in the clouds of our nearest planetary neighbor—or, it could merely be evidence of some weird, as-yet-unknown chemical processes taking place there.
On Earth, phosphine (PH3) is produced either industrially or by microbes that thrive in oxygen-free conditions. Therefore, at the moment, scientists do not have any other plausible explanation for the presence of this gas in Venus’s cloud other than that it is a possible sign of life.
The gas “is present at levels much higher than can be explained via known methods of production,” says Lewis Dartnell, an astrobiologist at the University of Westminster who was not involved in the new study.
The surface conditions of the rocky planet Venus is not conducive to life as we know it. However, scientists say that the environment of its upper cloud deck—around 53–62 km above the surface—could be mild enough to support life. Moreover, Venus’s clouds are highly acidic, and phosphine would not last long in such conditions. Therefore, if there is indeed a microbial life on Venus, it will be very different from what we see on Earth, so as to survive in hyper-acidic conditions.
An international team of astronomers, led by Professor Jane Greaves of Cardiff University, is credited with this path-breaking discovery. The scientists made the discovery using the observations from the James Clerk Maxwell Telescope and the Atacama Large Millimeter/submillimeter Array in 2017 and 2019, respectively.
The results of the study suggest the presence of phosphine in Venus’s clouds, but the quantity is scarce—in the range of 20 parts-per-billion.
To further explore the origin of phosphine in Venus’s atmosphere, scientists suggest that more observations and modelling are the need of the hour. Over the decade, several missions to Venus, including India’s Shukrayaan-1, have been planned by space agencies across the globe. The present discovery is likely to give a fresh impetus to exploration missions to the shiny planet.