Figure 1: A close-up view of Venus; the different gases present in its atmosphere are visible.
Source Credit: MIT News(LINK)
In the last issue, one of our writers, John, wrote about the possible existence of life on Titan, despite most of humanity’s extraterrestrial endeavors being focused on Mars. Having read his article and become interested, I delved into the topic and found another recent development in our planetary system; the discovery of phosphine in Venus’ atmosphere, pointing to the possibility of life existing on the planet.
Before we move onto talking about the specifics of said discovery, let us examine why exactly investigating extraterrestrial life is so important. Looking for life outside of our planet is a somewhat odd endeavor — we cannot disprove the existence of other life, so as long as we do not stumble across another galactic civilization, the hypotheses that fuels much of space exploration cannot be supported nor revoked.
Why then, are we so keen on looking for life beyond Earth? The answer may range from something simple, such as that we are merely curious, to more ominous answers such as the future possibility of humans relocating to another planet. Perhaps it is a reflection of the rate of our technological growth — the small boundaries of Earth cannot satisfy our scientific yearnings, leading us to venture outside of its atmospheres into new areas. Whatever the reason, it is indisputable that space exploration is the forefront of modern human development and may help us cultivate new knowledge and abilities. Exploration, in fact, has always been responsible for the most drastic changes in human society, starting from the exploratory ventures of early mankind to the Age of Discovery in modern times. Our more recent infatuation with space exploration, in a sense, may be no different. We have merely evolved from exploring new lands on boats to sending satellites to space.
It is with this understanding that we take a look at the discovery of phosphine on Venus and why this points toward the possibility of life on the planet. Light signatures associated with phosphine were first detected in Venus’ atmosphere by a team of scientists from MIT and Cardiff University. Phosphine, because of its chemical qualities, are impossible to create with abiotic processes that could possibly occur in Venus’ harsh conditions. This logic points to two possibilities: that either life does exist on Venus, or that this phosphine was created through processes that scientists did not expect that the temperature and chemical composition of Venus could recreate.
On Earth, phosphine is created by industrial sources such as fumigants — toxic gases — or from biological sources such as microbes. Humanity has yet to find other chemical processes that could possibly result in the creation of phosphine, and the chances of doing so are very slim, given that humans have already found all naturally-occurring elements and have examined possible chemical reactions between them. Thus, the likelihood of the second possibility is near to none. Moreover, given that industrial sources do not exist on Venus, the discovery of phosphine unquestionably points toward the existence of life on the planet.
However, there is a potential counterargument: that the very sighting of phosphine by scientists was incorrect. A new team of scientists have reasoned that the light signal may have come from sulfur dioxide (SO2), a common gas on Venus. They have also listed a number of other reasons why life forms existing on Venus is very unlikely, many of which discuss Venus’ uninhabitable environment.
Although Venus is approximately the same size and mass as Earth, its soaring temperatures and lack of nutrients make it difficult for life forms to exist on the planet. The only possibility of life is in the planet’s atmosphere, which is also quite inhospitable as it contains thick clouds of sulfuric acid and liquid droplets that are billions of times more acidic than the most acidic environment on Earth.
However, there is a tiny strip of area with the right temperature and environment for life to potentially exist within Venus’ atmosphere. Located between 48 to 60 kilometers from the planet’s surface, temperatures are relatively lower at 30 to 200 degrees Fahrenheit. This, coincidentally, was where scientists located the phosphine light signals.
Conclusively, it is somewhat unclear whether the phosphine sightings were truly correct and whether or not phosphine is absolute evidence of the existence of life. Nevertheless, this recent discovery is an exciting development in our continuing effort to find extraterrestrial organisms. It can also be argued that all space exploration is unclear; we are uncertain as to whether microbes inhabit Mars — or any other planet, for that matter. The purpose of exploration is not to reach a definite conclusion, but rather to strive to make new discoveries that will help us continue to modify our ever-changing perceptions of ourselves and the world around us. We did not know why apples fell before Newton discovered gravity; our works on Mars, Pluto, and Venus may just be efforts to find the right cosmic apple.
Q&A Section
Sally: Are there other evidence that hints at the possibility of life on Venus? Also, what kind of research are scientists doing to confirm their discoveries or is there no way to do so?
While there have not been much other evidence that hints at the possibility of life on Venus, there has been ongoing research to prove the existence of phosphine on the planet. For example, researchers have been conducting repeated experiments to see if the initial phosphine detections were reasonable possibilities, and have also been researching to find if other organic chemical methods of creating phosphine are possible.
Xavier: Supposing that life is proven to be thriving on Venus, what can we expect the organisms to look like? Any chance of intelligent life?
While we cannot be completely sure what the organisms would look like, we could likely envision them to be similar to the microorganisms that inhabit the extreme environments on Earth, such as in hydrothermal vents or the inside of glaciers. I would doubt that we could expect signs of intelligent life, given the aforementioned extreme conditions of the planet.
Eric: How could sulfur dioxide and phosphine have been mistaken for each other, and what implications do errors like these have on our search for life in general?
Sulfur dioxide and phosphine give off similar light signals in the chemical component-detecting software used by MIT researchers, especially given that sulfur dioxide is a commonly-occurring chemical on Venus. Errors like these do not have severe implications on our search for life in general, because as long as they do not conclusively and absolutely point to the existence of life, all our scientific findings are merely hypotheses.
Hannah: Based on what you said in your article, it seems that even if life does exist on Venus, the environment would still be nearly impossible for humans to live in. Despite this fact, why do you think scientists are still continuing studies about Venus?
I think the sheer idea of there existing other forms of life outside of Earth, especially so in our own solar system, is the reason why scientists are still continuing studies about Venus. The very possibility that life may exist outside of our planetary boundaries also points to the fact that humans could potentially inhabit other planets in the distant future, so the fact that Venus’s climate is too extreme for humans to currently live in does not inhibit scientific work on the planet.
John: How do light signatures work? Are they reliable methods through which we can identify the existence of certain substances?
Also known as a “spectral fingerprint,” light signatures work by interacting with the bonds in the molecule it is sensing, then using the resonances from the bonds to analyze their frequencies. These frequencies allow for the scientists to match the faraway light signatures to a type of molecule, thereby identifying it. This methods of identifying the existence of certain substances is very reliable, given that different molecules have different bond frequencies.
Wooseok: Is it just a coincidence that the strip of land with relatively low temperatures was where the light signals were detected? In other words, are there any direct connections between the light signals and the low temperatures?
It was a coincidence that the light signals were detected in the strip of land, which makes the argument that life exists on Venus all the more convincing; the scientists were not actively looking for the light signals strictly in that area, but it was where they happened to be found.
Works Cited
Chu, Jennifer. “Astronomers May Have Found a Signature of Life on Venus.” MIT News, Massachusetts Institute of Technology, 14 Sept. 2020, news.mit.edu/2020/life-venus-phosphine-0914.
Shostak, Seth. “Why Look for Extraterrestrial Life?” SETI Institute, SETI Institute, 30 June 2020, www.seti.org/why-look-extraterrestrial-life.
Witze, Alexandra. “Life on Venus Claim Faces Strongest Challenge Yet.” Nature News, Nature Publishing Group, 28 Jan. 2021, www.nature.com/articles/d41586-021-00249-y.
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