A bio-signature

last week, Made an incredible announcement Search for extraterrestrial life: Phosphine gas found in Venus’ clouds – a potential indicator of life or “bio-signature.” Now some gases may be false positive for biosignatures because they can be generated by other chemical processes on a planet, such as photochemical processes in the atmosphere or geological processes below the surface that produce a given gas. For example, methane can be a biosignature, and We are hunting it on Mars, But we also know that methane can be generated geographically. The discovery of phosphine in the clouds of Venus is remarkable because we do not know of any way to create phosphine without phosphine being abusive or life part of the equation. Question – How many lives ??

“Possibility”

Once a biosignature is detected, one way to rule out false positives is to look at the concentration of suspicious gases and see if they can produce enough gas to sustain life. The phosphine gas in the Venus clouds was found at a density of 20 ppb (one billion parts). If the biomass required to create this gas concentration is high, an unfamiliar agiotic process is still in operation. This is because, although Venus may have life, the need for higher densities in a world where surface habitat is generally assumed to be zero is starting to reduce your alien credibility.

Past studies have already examined the biomass needed to determine whether a biosignature gas is in fact a by-product of living things and not some other unknown agiotic process. In Caesar, Baines, Hu 2013 A study has been published with the foresight that most of our thunderstorms are going to look into distant alien atmospheres, to determine if atmospheric chemistry is an indication that something is living there. Such a signal is chemically unbalanced – gases that should not be formed or an excess of a particular gas. For example, if someone looks at our planet a light-year away, they will see that the concentration of oxygen in our atmosphere is ten orders of magnitude greater than the chemical equilibrium. That imbalance creates life on Earth and adds oxygen to the atmosphere. We do not know of any other agiotic process that causes that amount of discilibrium. Another signal is the presence of a gas that has no source other than life. That’s where phosphine works. In the absence of other known processes, Dr. Sarah Caesar Her team explored whether “a bio-signature gas can be produced by a physically reliable organism.” Although we do not know exactly what an alien is, we know that certain chemical and physical processes are universal. Some chemicals only get a lot of energy. Therefore, the study used these universal principals to avoid a trap of “universality” – based on all the biological models we know of on Earth.

Dr. above. Based on the models of Sarah Seeger and her team, New study by Mansavi Lingam and Abraham Loeb Released September 16th^th This applied to models for the detection of phosphine on Venus. Results?

“We found that the typical biomass density predicted by our simplest model is several orders of magnitude lower than the average biomass density of the Earth’s celestial biosphere.” – Gender and Loeb 2020

In other words, we have to live in the clouds of Venus to create the amount of phosphine we’ve found – much less than we do living in the clouds of our own planet. This is really exciting, because we can still consider life as a possible source of phosphine gas. A possible little life gives us a signal that we can see from the earth and it tells us that it is there. If the amount of biomass required is really high, we will have to look for other agiotic processes that we do not know about, because the high concentration of life on Venus is unlikely to exist.

Life in the clouds

So, now is the exciting part of specifying what kind of life phosphine creates. Until 1967, The best scientific communicator and astronomer Carl Sagan and biophysicist Harold Morotwitz ulated Hitch about life in the clouds of Venus. For The first few billion years In its history, Venus would only be more suited to life if it became the familiar Venus of the last billion years. Not only does life have time to evolve on the surface, it also has the potential to migrate into the clouds. The surface of Venus, which is covered in clouds and dense atmosphere, is a little uncomfortable at 460 degrees Celsius – enough to melt lead. Venus means “cold” days Lead frost. So the surface came to life. But Clouds is a different story. At an altitude of 50 km above the surface of Venus, the temperature in the clouds drops to 5 സെ C, where water droplets form. In that layer of clouds, Sagan said, “there is no difficulty in imagining an indigenous biology.” Sagan and Morowitz envisioned a 4 cm diameter “float bladder”.

However, contemporary research suggests that microbial life may be better suited to Venus clouds. Dr. Sarah Seeger’s research predicts microbes Exists within drops Because in the cloud layers, “the need for a liquid environment, regardless of a biochemical makeup, is one of the common advantages of all living things.” The problem is that when the droplets become large enough, they fall to low altitudes and into destructive temperatures. The life cycle of these microorganisms varies between “small, empty spores, large, metabolically active, and drop-dwelling cells.” Therefore, specific microorganisms live in a nutrient-rich drop of water. The water condenses, but as it accelerates and evaporates at low clouds, it evaporates at a radius of about 33-48 km. In the vacuum, it is lifted by the wind, which brings the microbes back to a higher altitude, where it regenerates itself in a new water drop home. During the metabolic activity of the microorganism within a droplet, it is likely to produce phosphine.

I do not know. In my imagination, it will be Mars first. In my fantasy quest for extraterrestrial life, I have given several planetarium shows where we fly through the solar system and always gloss over that Venus is “too hot”. Yet, one of the best bio-signatures possible for life is from this hellish world. But that is science! We ulate, examine, study, and discover something even more amazing than we ined (although I am still rooted in the float bladder). #teamVenusfloatbladders)

More to explore:

In the biomass needed to make the phosphine found in Venus’ cloud decks – Gender, Loeb 2020

Phosphine gas in the cloud decks of Venus – Nature

Phosphine found in Venus’ atmosphere – an indicator of possible life? – Astronomy

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

What’s on the surface of Venus: History of the Venus program ”- Universe Today video

Life in the clouds of Venus? Sagan and Morowitz 1967 – Nature

Venetian Lower Atmosphere as Depot for Designed Microbial Life – Caesar in 2020

Biomass based model for estimating the potential of exoplanet biosignature gases – Caesar, Baines, Hu 2013