Global view of the surface of Venus, centered at 90 degrees east longitude.
What would it mean if there was life on Venus?
It only makes sense for some life to exist somewhere out there. A recent research paper has shifted the spotlight to our sister planet, Venus.
We are exposed to the notion of how vast the Universe is and how little we know about it – and while regular humans fantasize about elongated green creatures and devote considerable resources to production of science fiction movies, Earth’s top solid-bodied scientists focus on finding micro-organisms in the Solar System.
One may ask why would such an exploration be possibly impactful? The answer is simple: it would dethrone planet Earth as a habitat unique in regard to its capability of fostering the creation of life.
It is not breaking news that humanity will be able to settle on Mars much sooner than on Venus, as there is probably no water on Venus, rains consist of sulphuric acids, the atmosphere is so thick that the human body would get immediately squashed, and the surface temperature stands at 471 degrees Celsius. Effectively, despite being barren, cold, and thinly atmosphered, Mars presents itself as a more inviting opportunity for a species dreaming of a multi-planetary civilization.
However, while Mars is the primary destination for space exploration, recent research suggested that it is Venus where one should look for the proof of the existence of extraterrestrial life.
Phosphine gas in the cloud decks of Venus
“PH3 could originate from unknown photochemistry or geochemistry, or, by analogy with biological production of PH3 on Earth, from the presence of life”, reads the abstract of the article published on September 14, 2021 by Nature Astronomy
A stormy debate which occupies the minds of those in space exploration circles has been sparked by a paper published in Nature Astronomy by a team led by Professor Jane Greaves from the University of Cardiff, United Kingdom. It offered a promising attempt at challenging the current state of knowledge, where Earth is the only planet where life existed.
The time-consuming research involved observations of Venus through specialist telescopes, followed by a thorough analysis of data. It resulted in the team succeeding in identifying phosphine gas in the atmosphere of Venus. The ultimate claim is based on the analysis of frequencies at which different gases absorb light. There is a specific frequency of absorption of light (266.94GHz) which identifies phosphine gas (PH3).
Once the team identified the presence of phosphine gas in the Venusian atmosphere, they asked the only logical question: where could it come from? This is a pivotal moment, as the presence of phosphine gas could be considered as a possible indication of the presence of organic life forms at some point in Venus’ history.
Phosphine gas can be perceived as a bio-signature because the most likely explanation of its presence derives from the fact that it is produced by microorganisms that digest organic matter.
Prof Greaves and her team claimed that identifying phosphine gas in the cloud decks on Venus strongly supports the hypothesis that there was – or still is – some elementary life there, in forms of microorganisms that adapted to Venus’ harsh environment. According to their calculations, it is highly unlikely to otherwise explain the high amounts of phosphine gas found in the planet’s atmosphere.
It is not surprising that such a claim resulted in intense scrutiny from scientists involved in space exploration.
Professor Victoria Meadows of the University of Washington in Seattle, United States, disputed the findings, suggesting that Greaves and her team confused phosphorus trihydride (PH3) with sulfur dioxide (SO2), the latter known to be of abundance in the Venusian atmosphere. Indeed, there is a minuscule difference between the frequencies at which the light is absorbed by PH3 and SO2. Answering, Prof Greaves and her team conducted further research. They did not find any spectral lines which would suggest that Meadows’ claim was correct.
Another doubt was related to the question of whether the Cardiff team had not made an error while processing data – Prof Meadows claimed that error might have originated from incorrect calibration of the apparatus used by the team led by Prof Greaves. Again, further research was conducted, this time leading to the findings presented in the initial paper being amended: Greaves still claimed that phosphine gas is present on Venus, yet in lower amounts than what was first believed.
The debate continues and although the existence of life on Venus should be considered to be neither confirmed nor declined, it is worth considering the possible implications of such a possibility.
If we think about it thoroughly, what mankind is really interested in is finding another intelligent and self-aware life form, capable of amassing knowledge over generations. Yet, in order for that to be possible at all, the first condition is for any life to be present elsewhere than on Earth. The next steps we can follow are observing the history of our planet. Firstly, life evolved beyond one-cell organisms, enabling complex entities to appear. Secondly, some of these entities – animals – have formed nervous systems and then brains in order to adapt to the environment. Finally, homo sapiens became self-aware and capable of ensuring their survival by creating what we call civilisation.
The probability of such a set of events happening is dramatically low. The Universe, however, is as close to the notion of infinity as definition permits, both in space and time scale. Therefore, we arrive at a calculation where something with a probability of one to infinity is multiplied by an infinite factor. Effectively, the mathematical answer to the question of whether aliens exist is inevitably very vague and stands at simple ‘this cannot be ruled out’.
Confirming the existence of living organisms anywhere else in the Universe, even on the planet closest to Earth, would hugely alter the calculation in the aforementioned calculation. We could then quite safely assume that the Universe is full of life, which inevitably skyrockets the possibility for mankind to find an intelligent, human-like form of life.
Or not human-like at all. The beauty of the discovery in question is that it does not exclude the possibility that life still exists on Venus. If there would be organisms capable of surviving in the Venusian atmosphere, it would mean that life is way more resilient than we have ever imagined.