Does it feel like all eyes are on Venus these days? The discovery of the potential biomarker phosphine in the planet’s upper atmosphere last month has garnered a lot of attention, as it should. There is still some uncertainty around what the discovery of phosphine means.
Now a group of researchers say they discovered the amino acid glycine in the Venus atmosphere.
The paper announcing the search is entitled ‘Discovering the simplest amino acid glycine in the Venus atmosphere’. The lead author is Arijit Manna, a Ph.D. Research Scholar in Dept. of Physics at Midnapore College in West Bengal, India. The paper is on the pre-printed site arxiv.org, which means it has not been reviewed and published in a journal….
There are about 500 known amino acids, but only 20 are present in the genetic code. Glycine is the simplest of them all.
Although glycine and other amino acids are not biosignature, they are some of the blocks of life. In fact, they are the protein blocks. They are also some of the first organic molecules to appear on Earth. Glycine is essential for the development of proteins and other biological compounds.
The researchers used the Atacama Large Millimeter / submillimeter Array (ALMA) to detect glycine in the Venus atmosphere with spectroscopy. They found it in mid-latitudes, near the equator. That is where the signal is strongest, and nothing is seen on the poles.
In their paper, the authors wrote that “Its discovery of the atmosphere of Venus may be one of the keys to understanding the mechanisms of formation of prebiotic molecules in Venus̵7; atmosphere. The upper atmosphere of Venus may have gone through much the same biological process as Billions of years ago. “
Those two sentences wrapped up a real punch. Could there be some kind of biological process going on in the clouds of Venus? It “could” be a key, and it “could go through” the same thing that Earth did. What does this mean
First Phosphine, Then Glycine
In mid-September, a team of researchers reported the discovery of phosphine in the upper atmosphere of Venus (Greaves et al, 2020). Like glycine, it is also found to be stronger at mid-latitude. Phosphine can be a biosignature and is on Earth. But it can also be chemically produced, even though it requires enormous amounts of energy. It is seen in Jupiter and Saturn, where there is abundant energy for doing so. But Venus does not have the energy needed to create it.
The team of researchers who discovered phosphorus was cautious about their own findings. In their paper, they almost begged other researchers to consider the presence of phosphine without life-threatening. “Now, astronomers will think of all the ways to justify phosphorus without life, and I accept that. Please do, because we are at the end of our possibilities to show abiotic processes that can make phosphorus. “
A few weeks later, another team of researchers did just that. In their paper, called a theoretical perspective, they said that volcanoes could account for phosphine.
“We assume that traces of the amount of phosphide formed in the mantle will be taken to the surface of volcanism, and then released into the air, where they can react with water or sulfuric acid to form phosphorus.”
Phosphorus detection forms the background for this latest discovery. Both discoveries are part of the bigger questions around Venus: Their life or the potential for life on Venus? Or are these chemicals unrelated to life?
Researchers have identified a region of the Venus environment that can host life. This would be a strange and unusual arrangement from our perspective.
Venus is extremely unpleasant, for the most part. The atmosphere is acidic, the temperature is hot enough to melt the spacecraft, and the atmospheric pressure is crushing. But high in the clouds, between about 48 and 60 km (30 and 37 miles) above the surface, the temperature is not very deadly.
At that height, the temperature ranges from -1 C to 93 C (30 to 200 degrees F). This is very controversial, but some scientists think a kind of simple life can exist there, constantly multiplying, without ever touching the surface of the planet. Phosphorus is easily damaged, so it must continue to be made for it to be visible. Life at that height can be a source of phosphorus.
The new discovery of glycine only adds to the mystery and uncertainty. In their paper, the researchers suggested that Hadley cells could be responsible for providing a home for life.
“Hadley’s mid-latitude circulation can provide the most stable life-supporting conditions with circulation times of 70-90 days sufficient for the reproduction of microbial life (like Earth).”
Also, glycine detection corresponds to phosphorus detection. “The latitude dependent distribution of glycine roughly corresponds (within? 10?) With a limit to the detection of recently detected phosphorus and to the proposed upper boundary of the Hadley cell where the gas circulates between the upper and lower altitudes. “
Don’t Launch Spacecraft Yet
While an intriguing search and worthy of further study, the availability of glycine is nowhere near a knockout blow in the quest to find life elsewhere. The authors know this and carefully point it out.
“It should be noted that the discovery of glycine in the atmosphere of Venus is an indication of the existence of living but unstable evidence.”
It is a substance used by life, but not an indication of life.
Their paper points to some historical experiments designed to test the chemical origin of life on Earth. In 1953, today’s famous Miller-Urey experiment re-created the first conditions on Earth. The researchers created a chemical mixture of water, methane, ammonia, and hydrogen and then applied energy to simulate lightning. The result is a soup of more complex organic compounds.
The experiment produced glycolic acid, a precursor to glycine, and the results backed up the theory of abiogenesis. The glycine found in the Venus atmosphere can be produced by the same path as the Miller-Urey experiment. There are also other chemical pathways to glycine that are possible in the Venus atmosphere.
“In astrophysics, chemical physics and biophysics, routes of synthetic reactions of the simplest amino acid glycine, from simple molecules have great significance in chemical evolution and the origin of life,” the authors write.
“The discovery of glycine in the atmosphere of Venus may indicate the presence of an early form of life in the solar planet because amino acid is a protein block. Venus may go through a major stage of biological evolution.”
Or maybe not.
“Although on Earth, glycine produces biological methods, it is possible that in Venus glycine is produced by other photochemical or geochemical methods, uncommon on Earth.” Venus is very different from Earth, and there are processes taking place there that are not here on Earth.
Here’s where all the precautions come in.
The paper itself has not yet been reviewed by both. And there are some weaknesses in the results.
For example, the spectroscopic signal of glycine is very close to sulfur oxide, so it is possible that there is an error in the detection of glycine. And this is just a single discovery, not duplicated or verified. Also, glycine is the simplest of amino acids and is found elsewhere. This is noticeable in comets and meteorites, where there is really no hope in life.
It is also not seen on any other planet than Earth, which means it is surprising to be seen in a rugged world like Venus.
To find out, we need more spacecraft visiting Venus. “A mission of Venus with direct sampling from Venusian surface and clouds could confirm the source of glycine on the planet,” the authors state.
The discovery of glycine, if confirmed, is another intriguing development in the desire to understand life increasing. Or we may be shown that the chemistry that appears to be prebiotic is only prebiotic in rare cases, and in the rest of the time, it means nothing at all. There is much we do not know, and missions to Venus are the only way to find out more and answer some of our questions.
But for now, we can be sure that life was not found on Venus. Instead, we may have discovered another piece of jigsaw puzzle that is Venus’ complex environment.
This article was originally published by Universe Today. Read the original article.