How many lives will it take to make a phosphine signal on Venus?

A biosignature

Last week, an incredible announcement was made about the discovery of life in the outside world: the phosphine gas found in the clouds of Venus – a potential indicator of life or “biosignature.” Now some gases can be false positive for biosignature because they can be created by photochemical processes in the atmosphere like other chemical processes on earth or by geological processes beneath the surface that make up a given gas. For example, methane can also be a biosignature, and we are hunting it down on Mars, but we know that methane can also be created geographically. Finding phosphine in Venetian clouds is really remarkable because we currently know no way to make phosphine expressively or without making life part of the equation. The question is – how much life ??

“Reasonable”

Once a biosignature has been discovered, one way to disprove false positives is to look at the concentration of gases in question and see if any reasonable amount of life can produce gas. Phosphin gas was found in the clouds of Venus at a concentration of 20 ppb (parts per billion). If the biomass required to create this concentration of gas is high, then an unknown abiotic process may still be at work. Because when Venus can have life, the need for a concentrated concentration of life on the Earth usually starts to reduce your alien credibility due to having a zero surface population.

Past studies have already turned to the calculation of biomass needed to determine whether biosignature gas is in fact a product of living animals and no other unfamiliar process. Sear, Bains and Hue published a study in 2013 with foresight that most of our ET prey is potentially looking to distant alien environments to determine if atmospheric chemistry is a sign for us that something is there. Such signals are chemically out of balance – gases co-exist which should not be, or an excess of a certain gas. Is greater than ten magn magnitude. That imbalance creates oxygen from life on Earth and is added to the atmosphere. We do not know if there is any other abiotic process that is responsible for the degree of disabilization. Another sign is the presence of gas without any known source other than life. That’s where phosphine comes into play. In the absence of other known processes, Dr. Sara. Sara Caesar and her team discovered “whether biosignature gas can be produced by physically rational biomass.” And while we do not know exactly what an alien creature will be, we do know that some chemical and physical processes are universal. Only so much energy can be obtained from certain chemical reactions. And so, this study used these universal principals to avoid the trap of “tercentricity” – the basis of all the biological models on the life we ​​know on Earth.

The above Dr. Sara. A new study was released on September 16 by Manasvi Lingam and Abraham Loeb, based on Sara Sier and her team models.^M Who applied models in the recent discovery of phosphine on Venus. The result?

“We find that the density of the typical biomass predicted by our simple model is many orders of magnitude smaller than the average biomass density of the Earth’s air biosphere.” – Lingam and Loeb 2020

In other words, living in the clouds of our own planet is much less than living in the clouds of Venus to create the level of phosphine we have discovered – an impenetrable amount of life. That’s really exciting because it means we can still consider life as a potential source of phosphine gas. By signaling a small amount of potential life we ​​can see from Earth that it is there. If the amount of biomass required is really high, then we should look for other abiotic processes that we do not know about, because the concentration of life is less likely to exist on Venus.

Life in the clouds

So now we get to the exciting part of guessing what kind of life phosphine can make. As in 1967, the great science communicator and astronomer Carl Sagan, and biophysicist Harold Morotwitz speculated about life in the clouds of Venus. For the first few billion years of its history, Venus may be the most favorable for life, of which we are familiar in the last billion. Life not only had time to evolve on the surface but probably also migrated into the clouds. Spread across clouds and super ga ense atmosphere, the surface of Venus is a bit uncomfortable at 460 Celsius – hot enough to dissolve the lead. The “cold” days on Venus mean lead snow. So the surface is out for life. But clouds are a different story. In clouds 50 km above the surface of Venus, the temperature is 5 cm. As much as comes down where water droplets form. Sagan said that in that layer of clouds “it is by no means difficult to imagine indigenous biology.” Sagan and Morovitz envisioned a living “float bladder” about a centimeter in diameter to carry a bubble of hydrogen to stay inside.

However, contemporary research suggests that microbial life is more appropriate for Venus. Dr. Sara. Good Caesar’s research predicts microbes within the droplets of cloud layers because “the need for a fluid environment is one of the most common characteristics of all life, regardless of its biochemical makeup.” The problem is that once the dot is large enough, it proceeds to reduce the itching that comes down to the destructive temperature. The life cycle of these microbes then “changes between the state of small, destroyed seeds and large, metabolically active, dot-dwelling cells.” Therefore, the proposed microorganisms live in water droplets rich in nutrients. The water condenses, but it evaporates at the bottom of the rainforest and around ev 33–48 km, dispersing germs. In a weakened state, it is carried by the wind which returns the microbe to a higher itch where it re-bleeds itself into a small drop of water in the house. And during the metabolic active time of the microbe, it is potentially made … phosphine.

I would never have seen him come. In my imagination, it will be the first Mars. I have given many planetarium shows where we will fly out of the solar system in imaginary search for life outside of Earth and always manifested on Venus, “maybe too hot”. And yet, one of the best possible biosignatures for life has come from this hellish world. But it is science! We guess, test, learn and discover something more amazing than we can imagine (although I’m still the original for float bladders). #teamVenusfloatbladders)

More to explore:

Lingam and Loeb 2020 – on the biomass needed to produce phosphine discovered in Venus’s cloud decks

Phosphine gas in the cloud decks of Venus – Nature

Phosphine found in Venus’s atmosphere – indicator of possible life? – Astrobiology

Did scientists find signs of life on Venus? – The universe today

What’s on the surface of Venus: A History of the Venera Program “- Universe Today video

Life in the clouds of Venus? Teak and Morovitz 1967 – Nature

Venusian Lower Atmospheric Fog as a Depot for Densidated Microbial Life – See in 2020

Exoplanet BioSignature Gases – Biomass based model for estimating the potential of Caesar, Bains and Hu 2013