As we know that life needs water, but life as life No Know that it can run on concentrated sulfuric acid.
Chemistry of life as we know it will not work in one place like huge saturn moon TitanWhere it is so cold that ice behaves more like a rock, or in acidic clouds VenusBut a separate chemistry, which created all the expected pieces from different materials, could be a shot. Imagine cells that use methane, sulfuric acid, or even melted rocks the way your cells use water.
As A 2021 study By Massachusetts Institute of Technology (MIT) molecular biologist William Bains and his colleagues, it is revealed that, if we are looking for life as we do not know it, the best solvent can be a concentrated sulfuric acid – Stuff floating around Cloud of Venus,
Sulfuric Acid: Hazmat or solvent for life?
At the most basic level, life is a series of chemical reactions. Those reactions require a medium in which the chemist a solvent says: some fluids are enough that the molecules can swim around and mix, and there is a need to have a lot in a place. But just no one will do liquid; A solvent also requires breaking and transportation that cells need to live – without dissolving important molecules such as lipids and amino acids.
Connected: Foreign life can thrive in the acidic clouds of Venus, new study signal
But EarthWater fit the bill completely, but it may not only be liquid World Able to support the chemistry of life. One in New studyBains and his colleagues evaluated many possible solvents how they interact with the chemical formation blocks of life and how common they should be on rocky planets.
Candidates ranged from methane and athen, ammonia and liquid forms of carbon dioxide to stranger possibilities such as pitch and melted rock. Amazing champion is a chemical that we consider painful hostile to the life of the earth: centered sulfuric acid.
“Even compatible with very complex organic chemistry-centered sulfuric acid,” Mite astrobiologist Janusz Petkovsky, a co-writer of new studies, published in the journal Astrobiology in December, told Space.com .
A node for runner -up
Methane’s Titan’s frigid lakes have been a hotspot for speculation about life because we have never known it since NASA Cassini Shani Orbiter In 2005, the first of them sent home. Methane and ethane are gases at the temperature that we find here on Earth; To condensed in the liquid that fills the darkness Titan seasThey require temperatures around minus 250 degrees Fahrenheit (minus 157 Celsius). But in such extreme cold, atoms and molecules move dullly, so chemical reactions occur in slow speed – according to Petkovski, very slowly for life.
At the other end of the spectrum, the melted rock is out because the tremendous heat required to keep the rock liquid also breaks almost all organic molecules.
In some chemicals such as ammonia, there are all the right qualities to create good solvents for the chemistry of life. But this does not matter, because the same process that equips a rocky planet with ammonia also likes to stock it with water, and when this happens, two substances mix almost essentially. . This in itself is an interesting possibility for life, because ammonia reduces the cold point of water, which opens a wide range of places where life can avoid cold.
“While ammonia can play a big role in one Exoplanet It does on Earth compared to bio chemicals, “Bains and their colleagues wrote in their recent paper,” it is unlikely to be a solvent in itself. ,
Life on an acid world
Therefore, if astrobiologists ever find Foreign life With a strange chemistry that uses some liquid in addition to water, it is unlikely to be methane, ammonia, or melted rock – but somewhere outside, foreign life may have only pure sulfuric acid -filled cells.
How based on physics model Solar system Forms, sulfuric acid should be quite common on rocky planets such as Venus, and it is definitely good in dissolving things. But surprisingly, some most important Building block for life – Things like amino acids and lipids can swim around and can do chemistry in pure sulfuric acid, as easily in water.
“Classically, (sulfuric acid) is not seen as a great solvent (for life),” a astronomer Dirk Shulz-Makach of Berlin’s Technical University, who was not involved in recent studies, Told .com. “However, Bains and co-writers showed that a surprisingly large numbers and a variety of orgenics focused in sulfuric acid. It was quite surprising.”
Petkovski participated Some recent experiments According to Petkovski, some peptides (small chains of amino acids) were actually stable in sulfuric acid centered for months in centered sulfuric acid – so stable that the researchers eventually got bored with measurements. Earlier experiments were found 19 of the 20 amino acids that produce proteins in the human body are not dissolved in concentrated sulfuric acid. And one Study that is still waiting for colleague review It was found that not only the lipids (molecules that form our cell membranes) can withstand focused sulfuric acid, they actually begin to make a sac which look like vessels, the forearm of the membrane.
How does this happen? Funny, the key is water. Sulfuric acid on earth is usually found mixed with water, not in its pure form; It actually has water with some acids in it. And in that mixture, sulfuric acid catalyze chemical reactions between water and bonds that keep peptides together. Take water or acid either away, and they may not have reactions – so the peptides are either stable in the solvent, but not in the mixture of both.
“Centered sulfuric acid is a very different substance from thin acid,” said Petkovski. “It is a common misunderstanding that sulfuric acid destroys all organic chemistry. It is wrong. It is a very aggressive solvent, but it is very aggressive for specific parts in organic molecules like sugars.” (For all its lightness for amino acids and lipids, sulfuric acid will completely destroy sugars, which creates a lot of scaffolds on which life is formed.)
Somewhere in the universe, sulfuric acid lakes can do cheming with life forms whose original chemistry is slightly different from us.
Connected: Search for foreign life
What are made of foreign cells?
Foreign life forms that use sulfuric acid in place of water, perhaps with some subtle but significant differences in their chemical makeup, the earth will look surprisingly similar to life.
Petkovski said, “We should understand sulfuric acid as an environment that is not as foreign as we think it is.” (This does not mean that you can swim safely in concentrated sulfuric acid; Your cells are not developed for it. Please do not test it.)
For example, life in a sulfuric acid ocean will have to use something strong in place of sugars, which disintegrate very quickly in sulfuric acid. On Earth, sugars are how the cells store energy, and they also create parts of the cell walls. Aliens on Venus use some other types of molecules, which will do the same thing without falling.
“You have to adapt your organic chemistry as a solvent,” said Petkovski. “You have to choose chemical Lego building blocks properly, but you can finally reach with functionally similar structures.”
Other differences may be more subtle. Concentrated sulfuric acid does not break most of the amino acids used in our body, but it causes small changes in their “side chain”, wires of atoms that stick out to the molecule like a tail. And simply a single chemical bond makes the difference between a peptide that is stable in sulfuric acid and one which breaks down. So aliens on an acidic world can still be cells made of amino acids and proteins, but they can look just a little different than us.
The membrane that surrounds cells – keeping the chemical mechanisms of life out and outside everything – however, may seem to be familiar, although. Putika-like globules that were visible when Petakovski and his colleagues put the lipid into sulfuric acid, in fact formed in the same way as the puties are made in water: a process called pearling. First, make lipid tubes, and then those tubes separate into small vesicles. Life on an acidic world can use a separate set of lipids than people in our cell membrane, but the physics of the formation of the membrane looks similar, if Petkovski and its colleagues are correct.
Astrobiologists such as Petkovski, Shulz-Makuch, and others are still not sure that all pieces of life as we do not know it can come together. But, as Petkovski said, they are not even sure how some groups of molecules on Earth jumped from chemistry to life.
Petkovski said, “We are away from detecting the origin of life in water, because we are in concentrated sulfuric acid.”
