Phosphine discovery could indicate signs of life on Venus
Three years ago, astronomers announced that they had detected phosphine, a molecule associated with biological activity on Earth, in the clouds of Venus. This unexpected discovery ignited a wave of excitement and debate within the scientific community.
Now, the team behind the find has unveiled new evidence, revealing that phosphine has been detected even deeper in Venus's atmosphere, all the way down to the clouds.
Led by Professor Jane Greaves from the University of Cardiff, the team had been teasing this data collection for a year, highlighting its additional robustness due to using a different instrument. Furthermore, they could track the changes in phosphine over time. Professor Greaves presented their findings at the highly anticipated National Astronomy Meeting 2023.
"We've made significant progress since we obtained the initial data in 2017," Professor Greaves shared with IFLScience. "We have now discovered phosphine on five separate occasions, allowing us to analyze its behavior. The focus is no longer solely on finding it; it's about understanding how it changes over time and what implications that might have."
Initially, the team reported their discovery in 2020 based on two independent observations. However, a subsequent study, which included members of the original team, failed to reproduce the findings, although they acknowledged that their search was limited to the upper regions of Venus's clouds, leaving the possibility of phosphine existing in deeper layers.
The recently collected data, obtained using the James Clark Maxwell Telescope (JCMT) in Hawaii, is considered comprehensive. It reveals the presence of phosphine in the upper atmosphere of Venus and provides evidence of its existence atop the planet's clouds. This suggests to the team that the source of phosphine is either within the clouds or beneath them.
"Finding phosphine in these regions demonstrates that there is indeed a source, be it within or below the clouds," Professor Greaves explained. "This is particularly intriguing because the clouds are the most interesting part...there is a remote possibility that some form of life may exist there."
The notion of life on Venus.
The notion of life on Venus generated immense excitement in 2020, spawning numerous headlines proclaiming the discovery. However, it is important to note that there is currently no direct evidence supporting this claim.
Nonetheless, the team believes that certain aspects of the data lend credence to this unlikely scenario. For instance, the quantity of phosphine detected does not exhibit significant fluctuations across the different observations. In contrast, sulfur dioxide, associated with volcanic activity on Venus, can vary greatly—more than tenfold over various timeframes.
"The amount of phosphine seems to change at most by a factor of two, either increasing or decreasing. It is relatively stable, which is significant when interpreting the data," Professor Greaves emphasized.
The team remains committed to unraveling the mysteries surrounding this enigmatic molecule on Venus and eagerly anticipates the upcoming missions to the "morning star." NASA has planned multiple missions to Venus (although one has encountered delays), while the European Space Agency is preparing a mission to study the planet's atmosphere.
However, Professor Greaves and her team are particularly enthusiastic about a smaller mission initiated by the Breakthrough Initiatives, which aims to dispatch a probe to investigate Venus's clouds for phosphine and the potential presence of life.
As we venture deeper into the exploration of our neighboring celestial bodies, the mysteries of Venus continue to captivate our imagination. Whether or not phosphine on Venus truly signals the presence of life, its detection has undoubtedly ignited a renewed interest in this enigmatic planet, propelling us further toward uncovering the secrets of our cosmic neighbors.