The number of amino-acids found has been mentioned in many on-line media, but it is completely meaningless.
There exists a huge number of amino-acids, most of them are not made or used by the known living beings and of those made by living beings even fewer are used in proteins.
A very large number of random amino-acids have also been found in various meteorites, because they easily form from the most abundant chemical elements in the Universe, H, C, N and O, whenever there is not enough oxygen to oxidize everything else, but among them only about 10 of those used by living beings have been found, i.e. about one half of the amino-acids used in proteins.
What would have been interesting to know about the Japanese asteroid probe would have been if, among the many amino-acids found, there have been also the same about 10 amino-acids previously found, or only a part of them, and if there has been found any other amino-acid with biological importance besides those ten.
The press release mentions only glutamic acid and valine, 2 simple amino-acids which belong to those 10 about which it is well known that they can easily be synthesized in abiotic conditions.
> There exists a huge number of amino-acids, most of them are not made or used by the known living beings and of those made by living beings even fewer are used in proteins.
Thanks for the clarification, I did not know this. "Roughly 500 amino acids have been identified in nature, but just 20 amino acids make up the proteins found in the human body."
> but among them only about 10 of those used by living beings have been found, i.e. about one half of the amino-acids used in proteins.
So you are in fact underscoring just how significant this finding is by Japan on just one out of more than "between 1.1 and 1.9 million asteroids larger than 1 kilometer (0.6 miles) in diameter" in the asteroid belt [2]
The returning of the asteroid sample and its analysis by Japan are very important and interesting.
The problem is with the news report, which does not include the information that could have been interesting about the results. Instead of that, the news report stresses the number of amino-acids that happened to be found in the sample, which has an extremely low importance.
Any extraterrestrial sample of matter which has condensed from a gas with the oxygen content under a certain threshold, and which has not been exposed to high temperatures that would vaporize the volatile organic substances is guaranteed to contain many amino-acids. Confirming the expectations is not newsworthy.
If the news report would have contained the list of amino-acids, or better, also their proportions, that could have contained some useful information.
A complete list might be too much in a news report for the general public, but there is some useful condensed information that could have been given instead of a complete list, i.e. how many proteinogenic amino-acids were among the 23, how many of the amino-acids were left-handed and how many right-handed, and whether there was any amino-acid which has not been found previously in matter of abiotic origin.
> press release mentions only glutamic acid and valine, 2 simple amino-acids which belong to those 10
"Proteinogenic amino acids such as glycine, D,L-a- alanine as well as non-proteinogenic amino acids including b-alanine, D,L-a-aminobutyric acid were identified. The chiral amino acids are present as racemic mixtures (D/L ~ 1), which is indicative of extraterrestrial, non-biological origins."
This is an earlier report about the progress of the chemical analysis of the asteroid samples, at a time when they had identified only 10 amino-acids and when they had not identified yet the glutamic acid and the valine.
Unlike in the news report, here the relevant information is present.
However the results do not contain any surprise. As expected, there are equal quantities of left-handed and right-handed amino-acids (unlike in living beings) and all the amino-acids are among those simple enough to be synthesized spontaneously, in the absence of life.
Building on that, it's ever more clear that the needed building blocks needed to create life are floating around in space, they seem to be very common. Wherever there are adequate conditions (water can exist in liquid form, not too harsh of an environment), amino acids will be deposited there from meteors, they could chemically interact and over lots of time more complex things can arise. So there's an excellent change for some kind of life (microbes at least) to be widely being created across the universe.
They cooked a sample of Ryuguu and drove off about 15% of its mass, mostly in the form of H2O and CO2. That is, Ryuguu is wetter and more carbon rich than the earth.
Iron, Silicon and Aluminum are there in abundance. (Gerard K. O'Neill and many science fiction writers have gotten wrong the idea that you need M-type asteroids to get iron.) Astronauts found high quality hematite ore on the moon.
If you wanted to make large solar sails (say to be a sunshade the Earth-Sun L1 point) you would probably de-volatilize materials by using heat and possibly oxygen. It would be ideal to convert hydrocarbons to carbon monoxide so you can do C1 chemistry to make plastics. You have waste CO2 no matter what (it offgases from carbonates and other chemistry) so you will need the same kind of chemistry people are talking about for capturing CO2 and using it as a chemical feedstock.
The "metal line" and "stone lines" would reduce the devolatized rock to produce silicon solar cells, electric connections, mirrors, etc. You will make storage tanks from iron, the devolatilization process could be a little awkward because you will need storage tanks to put the gate.
The one resource I'm not sure about is nitrogen, which is important for making chemistry work. (Say you want to make a sail out of Kapton instead of Polyethylene.)
Nitrogen is likely to be a limiting reagent in a lot of interesting processes in space, finding amino acids is good news but it's not clear how much nitrogen we're talking about.
In Gundam the O'Neill colonies are less plausible than the giant robots because the huge airspaces require large amounts of inert gases such as nitrogen, argon, helium, or SF6. I find it profoundly annoying that phys.org publishes a story every week or so about how lunar colonists could make oxygen for 'breathing' which is a way to burn out and not fade away unless you have four parts of some other gas.
Is the article suggesting that they think these amino acids have survived in space for (over) 4.6 billion years? That's astonishing, I'd have thought that over that stretch of time the background radiation would have broken the atomic bonds
> A total of 23 types of amino acids were found in asteroid samples brought back by Japan's Hayabusa2 space probe, according to new studies published in the journal Science and elsewhere, shedding further light on the origins of life on Earth.
This intersects with a raging debate in Origins of Life research. The Miller-Urey experiment demonstrated the production of amino acids from simple gasses thought the be present in the early Earth atmosphere and energy.
The problem is that you can add amino acids into a flask, stir, and not much will happen. You can pump in all the energy you want and all you'll get it tar. Before you can even start to make proteins, which is what makes life, you need enzymes. The trouble with enzymes is that they're, well, proteins.
So how do you get the proteins that make proteins in the first place?
One line of investigation says that you don't. What happens instead are stepping-stone chemical processes that turn energy from the environment into self-reinforcing cycles that build complex molecules. Over time chemical evolution takes place to produce self-reinforcing systems that make something that's very close to amino acids and/or proteins. We don't know what these processes are, but we can deduce their necessity given the above conundrum. Chemical evolution is a process we observe on the macro scale when, for example, viruses evade vaccine defenses.
In other words, finding amino acids just says that the processes that produce amino acids are ubiquitous. This is hardly surprising given the molecular simplicity at play. There's just a handful of atoms and they pop together following well-understood rules. The paths to making amino acids from simpler inputs is short, well-defined, and not entropically disfavored. It can (and does) occur abiotically.
Finding enzymes or other complex proteins above statistical background levels on the other hand would be different. That would be a world-changing find because it would be strong evidence of previous life. Even more, you'd be hard-pressed to find any other explanation.
But it's not just proteins. Any sufficiently complex molecule found above expected statistical levels due to random reactions would be strong evidence supporting previous life.
As an aside, finding enantiomerically-enriched amino acids would also be an important finding for similar reasons. The article doesn't discuss this, though.
For a high-level overview of what all of this about, check out Lex Fiedman's interview with Lee Cronin:
I agree that the step from simple molecules like amino acids to life is far from clear. A nice candidate is the RNA, because it can have enzymatic properties and also store information and somewhat self copy. More details in https://en.wikipedia.org/wiki/RNA_world
Self-replicating proteins can happen by a chance. And if the chance is too small for the life to happen accidentally in the known universe, then this is an argument that there are more than we can see or there were many universes in past.
The simplest self-replicating system we know of that exists in some natural environment (not, say, in a carefully purified solution of energetic monomers) has billions of atoms. And self-reproducing proteins have never, to my knowledge, ever been demonstrated in any experiment.
If it turned out that going from amino acid to DNA/protein life is only possible by chance, then this an argument that there were at least 1e1000000 or whatever number past universes to allow to produce life.
Once we have a system capable of Darwinian evolution, yes. The problem is getting to such a system. This is the Great Handwave we see so often in discussions of origin of life.
Is it really a handwave to say we don't know? Sound pretty logical as opposed to just making something up or parroting some origin story like people have been doing for 1000s of years.
It's a handwave to say it's a hill climb when there's no clear mechanism to make it a hill climb. That's not saying we don't know, it's saying we DO know when we actually don't. It's basically assuming away the problem, the complexity gap between simple chemicals and systems we know can pile on complexity via natural selection.
Yes. A robotic space lasso can be used to herd the asteroids in low earth orbit. Next they are ground into a powder, packaged with little parachutes, and yeeted directly to consumers.
What? Amino acids from asteroids? At a sweet, sweet price of trillions of €$£ per gram? That’s gonna be one expensive burger. These are just bunches of CHNO atoms. We can synthetize them in any biochem lab easily enough.
Each amino acid has two mirrored versions. We use only one of them, so one half will be wasted.
Of the half we use, we don't use all of them, we use like 20+something. Some of the others may be transformed into one of the amino acids we use, but it looks like the found many weird amino acids, so a big chunk will be wasted.
Also, some amino acids are more useful and we can't produce some of them, so any mix is not equivalent. A mix produced by blending a cow is more similar to our preferred mix than a mix produced blending plants. The mix in the asteroid is even worse.
Bacteria can feed from more strange amino acids, so the bacteria in your guts will be happy and you will produce farts no man has smelt before. [Actually the smell depends on how much sulfur the amino acids have. I'm not sure in this case Anyway, expect diarrhea and other nasty stuff.]
Some of the weird amino acids may even be toxic, but let's be optimistic.
Probably, yes, in exactly the same way (though with significantly less nutritive value) that fill dirt or construction rubble can be used as a meatless protein source.
There exists a huge number of amino-acids, most of them are not made or used by the known living beings and of those made by living beings even fewer are used in proteins.
A very large number of random amino-acids have also been found in various meteorites, because they easily form from the most abundant chemical elements in the Universe, H, C, N and O, whenever there is not enough oxygen to oxidize everything else, but among them only about 10 of those used by living beings have been found, i.e. about one half of the amino-acids used in proteins.
What would have been interesting to know about the Japanese asteroid probe would have been if, among the many amino-acids found, there have been also the same about 10 amino-acids previously found, or only a part of them, and if there has been found any other amino-acid with biological importance besides those ten.
The press release mentions only glutamic acid and valine, 2 simple amino-acids which belong to those 10 about which it is well known that they can easily be synthesized in abiotic conditions.