Ryugu asteroid samples contain all DNA and RNA building blocks
phys.org
phys.org
One longstanding theory is that life first began on Earth when asteroids carrying fundamental elements crashed into our planet long ago.
The missing part is how do they form self-replicating mechanisms capable of evolution. I doubt an asteroid with a bit of organic dust is enough for that. If such small amounts suffice we should see the formation of new life forms from scratch, today, left and right I think?
I've read about experiments like this but only at lab beaker scale.
Of course people can, and do, try to replicate early earth environments and self-assembling proto-cells, but I'm not sure how intellectually satisfying any self-replication success from these "designer experiments" would be, unless perhaps done on such a large scale (simulation vs test tube?) that any conclusions could be made about what likely happened in nature - just how specific do the conditions need to be?
The discovery comes after these building blocks of life were detected on another asteroid called Bennu, suggesting they are abundant throughout the solar system.
We've barely started to look, other than on Mars, and notably we are seeing possible signs there. There may even still be primitive life there.
If we do find life of Mars, or say Europa, i.e. in the very first places we look for it, that that would be highly suggestive that it is extremely common (at least in primitive form).
You don't need to be an expert to be curious. Many here would surely like to know more. That's why non-IT stories are upvoted in the first place.
I'd also imagine that any type of chemistry that harvests energy from the environment is liable to find itself as a food source at the bottom of the food chain now that earth is teeming with life.
I think that self-replication, and ability to harvest chemicals and energy from the environment to make more of what you're built of, is the point of complexification of chemistry that is best considered as the most primitive form of life. From there you can go on to things that are capable of encoding structure and more complex chemical factories.
I suppose one signature of these earliest type of "emergent life" chemistries would be localized concentrations of things like these nucleobases that we know are the building blocks of life as we know it, but there may be other types of self-replicating chemistries that emerge too, that don't lead anywhere.
https://www.youtube.com/watch?v=rMSEqJ_4EBk
He's an interesting person overall - the long interview is well worth watching if you haven't already seen it - but the relevance here are his experiments with the emergence of self-replicating computer programs out of random components.
His starting point is entire "programs" (random sequences of 64 characters, of which only ~7 have any meaning - the program "statements" of the BF language), so perhaps more suggestive of this RNA world stage, but perhaps also of what came before it when there may have been collectively self-replicating soups consisting of discrete components rather then entire structural encodings.
What is correct is that RNA must have existed a very long time before DNA, during which RNA was the only nucleic acid.
Moreover, self-replicating RNA must have existed before ribosomes and proteins (where "protein" means a polypeptide that is synthesized using a RNA template).
It should be obvious that neither ribosomes nor protein-encoding RNA-sequences may exist before the existence of self-replicating RNA, because the living being in which those would exist would immediately die without descendants, together with its content of ribosomes and proteins.
So far so good, but some of the supporters of the RNA World theory claim that before the existence of protein-based enzymes, all chemical reactions inside a living being must have been catalyzed by RNA molecules.
This is an illogical claim, which is false beyond any reasonable doubt. Some RNA-based catalysts may have existed quite early, and some still exist today. However, any RNA-based catalyst could have appeared only at a later time after the establishment of RNA self-replication. The argument is the same as for protein-based catalysts, any living being with a RNA catalyst, but without RNA replication would die and the RNA catalyst would disappear without descendants.
So there is no doubt that the first feature of RNA that has appeared was self-replication, and at that time RNA could not have any other role inside a living being, because any such role would not have been inherited.
In other words, the first self-replicating RNA molecules were a kind of RNA virus, which multiplied inside the existing living beings, consuming energy and substances, without providing benefits. Only later, when eventually RNA templates have become the main method for synthesizing the useful components of a living being, something akin to a symbiosis between RNA and the rest of the living being was achieved, arriving to the structure of life that is known today.
For the first self-replicating RNA molecule to appear, the living beings must have contained abundant ATP and the other nucleotides. So the original role of the nucleobases in living beings was not the storage of information, but the storage of the energy required for synthesizing organic polymers. The self-polimerization of the nucleotides, which forms RNA, was an unwanted side reaction. In other words, before the RNA world, there already was an ATP world, which was the first user of nucleobases.
If RNA could not have been the material for making enzymes before the proteins, such enzymes must have been made from peptides (i.e. polymers of amino-acids), exactly like the enzymes of today, but those peptides must have not been synthesized using ribosomes, like the proteins. Such peptides still exist today and they remain widespread in all living beings, and they are named non-ribosomal peptides. Their mechanisms of synthesis are much less understood than the mechanisms of RNA-based protein synthesis. It is likely that more research into non-ribosomal peptides might provide a better understanding of how a living being without RNA could function.
In order to have a self-replicating living being you do not need a self-replicating molecule able to store arbitrary information, like RNA. It is enough to have a chain of synthesis reactions that closes a positive-feedback cycle, i.e. the products of one reaction are reactants for the next reaction and the products of the last reaction are the reactants for the first. If the chain of reactions produces all the components of a living being, growth and self-replication can be achieved.
The defect of such a living being is that evolution is extremely difficult. any mutation in one of the catalysts used in the chain of reactions is more likely to break the positive feedback and lead to death, instead of producing an improved living being. After the appearance of memory molecules, i.e. RNA and later DNA, which can store the recipe for making an arbitrary polymer molecule, it became possible to explore by mutations a much greater space of solutions, leading to a greatly accelerated evolution of the living beings.
Some related stuff:
* https://www.science.org/doi/10.1126/science.adt2760 They made RNA that copies itself, but it use as a starting point activated triplets of bases. i.e, if ATP is AR-PPP, they use a mix of something compounds like AR-P-AR-P-AR-PPP that stil have the triphosphate to store energy and be easy to link, but already have tree linked bases. This is even more difficult that a soup of ATP and friends.
* https://en.wikipedia.org/wiki/PAH_world_hypothesis The idea is that before the RNA word, there was something simpler, like this. Is it possible to use ATP to build more PAH? I also remember about a version of RNA that instead of ribose it used something smaller (glicerol?), but I can't find it.
RNA by virtue of its biochemistry is capable of self replication already. Sequence affinity alone is sufficient to drive structure formation. But without a template, structure can also form on its own (example of an open access paper exploring one such mechanism under certain conditions, 1).
This would be enough to kick start things.
1. https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002...
RNA is not capable of self replication. RNA by virtue of its biochemistry is only capable to be used as a template for replication, but the copying of the template must be done by a different molecular machinery.
If you put almost any RNA molecule in a jar together with monomers, you can wait until the end of time to see its replication.
Normally, RNA can be replicated only by a special enzyme, a RNA-dependent RNA polymerase. This kind of protein is used by many viruses.
It is hypothesized that a RNA molecule with a very special structure might have been used in the beginning as the catalyst for template-controlled polymerization, instead of a RNA-dependent RNA polymerase, to ensure self-replication. Some experiments have suggested that this is indeed possible.
Only after a self-replicating RNA molecule already existed, or if a RNA molecule existed in combination with a RNA polymerase that was produced by other means than by using a RNA template, other RNA molecules with various other functions could appear, and they would have been replicated by the already existing mechanisms, so they would be inherited by the descendants of a living being.
The link provided by you has nothing to do with RNA replication.
It describes a mechanism for the polymerization of nucleotides, which produces random nucleic acid molecules, not molecules that replicate an existing template.
A chemical reaction of this kind is what must have existed before the appearance of a self-replicating RNA molecule. Among the many random polymers produced before that, there was eventually one capable of self-replication, which started the evolution of genetic information.
This kind of reaction is what I have referred to as "side reactions" that happened during the use of ATP and of the other nucleotides as energy sources for the polycondensation reactions used in living beings to make macromolecules.
RNA molecules which can synthesize others have been produced in a lab.[1,2] Your claim is not only totally unsupported, it's been experimentally disproven.
Laboratory RNA production can be done with regular batch chemistry - no enzymes involved, so on a long enough time span heat and mixing would be able to polymerase candidates out of the primordial soup.
RNA self-affinity is well documented, double-stranded RNA viruses exist[2] so stable conformational arrangements of RNA are not only experimentally proven but so viable they exist in todays much more enzymatically hostile world.
The relative difficulty of the structure persisting is a point in favor it is as a replication medium, since if RNA could tightly bind RNA then templating new strands would inactivate it.
[1] https://www.science.org/doi/10.1126/science.1060786
Once there are forms that harvest and self-replicate, however, its expectable that there will be forms that delegate those features to others, like viruses. Cellular machinery that is required to implement those feature is not free, so parasitic forms would have survival advantage.
As to your question on we should see the formation of new life everywhere, well, if we looked hard enough we might? The answer is competitive exclusion. Abiogenesis would've occurred on a remarkably clean earth: any life now emerging from the proverbial space dust is both almost certainly not preconfigured for this biosphere, and is instantly drowning in competing microorganisms that are. Anything that does form is likely quickly killed either by natural forces or competing organisms. Meanwhile, our life goes everywhere: We've found living bacteria on the outside of the ISS!
They’d also have to contend with re-entry.
I think the OP meant that Earths magnetic field and atmosphere shields any terrestrial matter far more than than a bare asteroid that has no such protections, so it seems implausible at first glance that these things would develop or survive in open space rather than here.
I don't think "organics developed in the vacuum of space" is implied. Survived? Well we have samples now confirming, if I'm understanding the basis for the discussion (the article).
But what we don’t have is any examples of them surviving re-entry.
We also have a massive amount of those same compounds already here on the planet.
Causality is… tenuous. But not impossible.
Experiments do not tell us that something IS a certain way; only the ways it is not.
It’s nearly impossible, but it is the holy grail!
This experiment was to try to falsify one theory, yes, but as you note that is a very long way from the actual goal - or the level of certainty that the article is trying to imply.
These articles are written due to funding needs, which is why the articles are the way they are - and why the scientists themselves are likely cringing too when they read these articles. At least until the checks (hopefully) arrive.
The icy bodies from the outer Solar System that contain such organic substances are very easily vaporized during entry in the atmosphere of the Earth, so only a negligible fraction, if any, of the organic substances originally present in such a body would reach the surface of the Earth.
Then Earth collided with a great number of small bodies formed in the outer Solar System, which were rich in water and organic substances. This has modified the composition of the Earth towards the current composition. (Later Earth has lost a part of its hydrogen; because hydrogen is very light, it is lost continuously from the upper atmosphere, after water is dissociated by ultraviolet light; thus now the Earth has less water than around the appearance of life.)
This theory is likely to be true, so meteorites probably have brought a good part of the chemical elements most needed by living beings.
However, most of the pre-existing organic substances from meteorites must have decomposed and whatever has been preserved of them could not have had any significant role in the appearance of life here, because any living being would have needed a continuous supply with any molecules that it needed, otherwise it would have died immediately. Such a continuous supply could have been ensured only for molecules that were synthesized continuously in the local environment here, not for molecules arriving sporadically in meteorites and which would have been diluted afterwards over enormous areas, down to negligible concentrations.
You might consider that scientists advanced enough in their field to be launching missions to retrieve dust from asteroids are actually aware of basic facts relevant to their field of study.
I’m not saying the person you are responding too is right - but appealing to authority on something like this has a pretty bad track record.
Icy meteorites never survive re-entry that I’m aware of; and most carbon/chondrite ones don’t either, but they are the most common type that do. They tend to be ‘dry’, however.
Re-entry is a very ‘angry’ process.
The fragility of life-as-we-know-it that has undergone serial passage in an environment largely shielded from radiation, is not necessarily representative of putative life-forms carried by little rocks in space.
I am neither convinced for nor against the idea that life may have been carried over by interstellar rocks: on the one hand, its a major promiscuity between celestial bodies within star systems, galaxies, etc. on the other hand since we haven't discovered other life forms yet we have no idea on the missing probability densities of life in the bulk of the universe, so the Bayesian catapult can swing either way, we just lack the data for now.
The most popular is that asteroids and other interstellar bodies spread the building blocks, be it anywhere from amino acids to more complex building blocks. As evidence of this, there are hundreds of surviving asteroids on Earth that have been positively identified as having coming from Mars, which is pretty crazy because that basically takes a violent impact throwing debris into space and it making it to us many times over.
Part of the evidence for all this is how soon after the Earth formed that life appeared. We have positive evidence that this only took a few hundred million years. That's kinda crazy if you think about it. Also consider that the oceans likely came after the EArth formed.
Our galaxy is over 10 billion years old. The Sun is less than 5 billion years old. So that's 5+ billion years for stars and Solar Systems to form, evolve and die before the first fusion reaction in the Sun. Some of this needed to happen just to form heavy elements that are relatively abundant. Even that's kind of crazy. Heavy elements like lead, uranium and gold take relatively rare and violent events to eject material into space and make it to us. So what else made it to us?
If earth is about 4 billion years old, but it takes say 400 trillion years for natural processes to produce this chemistry, then it happened out there not here.
This was a key reason why Hoyle preferred a steady state model of the universe — the part of the universe we inhabit needs to be very, very old for this stuff to work out, according to his thinking. A minority opinion, for sure, his rejection of the Big Bang model and timelines lost him a lot of respect among his peers. And his ideas could be wrong, I’m just pointing out that historically panspermia proponents have taken this position as to “why not here”.
1 - Abiogenesis is incredibly rare. We don't know how much exactly, but it's a lot.
2 - Abiogenesis happened on Earth about as soon as it became possible. Where "as soon as" means within half a billion years, but it's still way quicker than its rarity implies.
A lot of people think panspermia is what made those two happen. Life had about a full billion years to appear in meteors before they could appear here.
There are some problems, e.g. that each meteor only stayed chemically active for less than that half-a-billion years Earth had. Or that all the meteors that fell on Earth had only a fraction of the material that was later available here. But IMO, the largest issue is that just doubling the time is absolutely unsatisfying.
Life can appear only on big planets or on big satellites, like the big satellites of Jupiter and Saturn, if they have a hot interior and volcanism.
Volcanism brings at the surface substances that are in chemical equilibrium at the high temperatures of the interior, but which are no longer at chemical equilibrium at the low temperatures of the surface, providing chemical energy that can be used to synthesize macromolecules.
Solar energy cannot be used for the appearance of life. Capturing light requires very complex structures that can be developed only after a very long evolution and which cannot form spontaneously in the absence of already existing living beings.
The only theory of panspermia that is somewhat plausible is that life could have appeared on Mars, which had habitable conditions earlier than Earth. Then, some impacts on Mars have ejected fragments that have fallen as meteorites on Earth and some remote ancestors of bacteria have survived this interplanetary trip.
There are many meteorites on Earth that have their origin in impacts from Mars, so at least this part is known as being possible.
Couldn't it have started in the accretion disk?
I would think the Sun, with its photons and charged particles, and the various electrostatics (like triboelectric) involved, would be the energy source. The disk starts, somewhat evenly distributed, with a whole annulus of surfaces in the Goldilockz zone, with water, etc present. Through time, these bounce off one another, eject bits, stick on others, preserve bits in ice, etc, smearing/spreading whatever allowed their synthesis.
Looks like this maybe has merit, with organic molecules found [1].
(I'm far outside by expertise here.)
Asteroids early in the solar system would be very radioactive due to short lived isotopes formed during the formation of the solar system. The existence of these isotopes is known from the patterns of decay products found in asteroids. The current guess is the early protoplanetary disk was bombarded by intense GeV-scale protons accelerated in the shock of a nearby supernova, causing large scale transmutation in the disk.
While a little radiation might have been beneficial at a later stage in the evolution of living beings, by increasing the frequency of random mutations, for a faster evolution, for the early living beings the only effect of radiation would have been to destroy them and prevent them for having descendants.
The only positive effect of the increased radioactivity in the early Solar System is that it is possible that not only the planets but also some smaller asteroids might have had warm interiors and volcanism.
So in none of the huge number of small bodies that exist in the Solar System there have ever been conditions for the appearance of life, but perhaps on some of the bigger asteroids there might have been such conditions, if they also had water and volatile chemical elements, besides a warm interior.
If life has ever appeared in such a place it must have used the same sources of energy that are known to have been used by the ancestors of life on Earth, i.e. gases and ionic gradients produced by chemical reactions between water and volcanic rocks.
Nuclear energy is a source of energy for some current living beings, though. Underground ecosystems live on hydrogen produced by radiolysis.
I think that is putting the cart well before the horse. Earliest "life" I would say looks something like a short sequence of random RNA, in some structure (as in secondary), in some solution, among some nucleotides, where brownian motion lead to collision with nucleotides in the chain that grow the chain and/or template off the chain and make a copy. The energy requirements for this sort of pre cell life are far less than cell based life which has to spend energy on cell membrane or wall building. Energy could be quite low, it would just reduce the number of interactions over time. Likely also that this pre cell "life" would not die either so long as it is protected somewhat by cosmic radiation bombarding the chain (although to an extent this is also a ripe source of mutagenic potential).
What you describe is a perpetuum mobile.
No kind of life can exist without a continuous flux of energy. The formation of any organic polymers requires energy, it cannot happen spontaneously.
Nucleotides that collide do not form polymers in water. The polymerization of nucleotides and of amino-acids and of most other organic macromolecules is done by water extraction (a.k.a. polycondensation).
Water extraction inside water requires considerable energy (i.e. you must dry some thing while it is still submerged in water). This is provided by certain dehydrated molecules, like ATP, from which water must have been extracted as a result of capturing some energy from the environment.
The common ancestor of all living beings known on Earth obtained energy by the reaction between free hydrogen (dihydrogen) and either carbon monoxide or carbon dioxide. It is likely that the capability to use carbon dioxide has appeared later and the very first living beings were powered by the conversion of dihydrogen and carbon monoxide into acetic acid. The energy from this reaction was captured because the first result of the reaction was not free acetic acid, but acetic acid condensed with another molecule, like in the acetyl-CoA that is used today by all living beings. Than that condensed molecule could be used to extract water from other molecules, producing dehydrated molecules like ATP, which can be used for the polymerization of nucleic acids.
There is no way to circumvent the need for a continuous source of energy for the appearance of life. Besides the H2 and CO gases, there was an alternative source of energy that was used very early, but it is not known if it was already needed for the initial appearance of life or it began to be harvested at a later stage. This second source of energy is the difference in ionic concentration between the acidic water of the primitive ocean and the alkaline water that is produced by dissolving volcanic rocks in places like hydrothermal vents, where H2 and other gases are also produced. The ionic concentration gradients produce ionic currents, which can power certain chemical reactions, like they also do in all present living beings.
However, I would not describe those as small. The majority of the interplanetary bodies that orbit the Sun and which fall from time to time on Earth as meteorites are far too small to have ever had conditions for the appearance of life.
Even an asteroid like that which has wiped out the dinosaurs, with a diameter of a few km could not ever have suitable conditions.
Only relatively large asteroids, presumably with diameters from tens of km to hundreds of km, might have had warm interiors and volcanism for enough time to allow the appearance of life.
Such asteroids must also have been among those distant from the Sun, in order to contain enough water and volatile chemical elements.
The fact that the most volatile chemical elements are those most important for life is not due to chance, but due to the necessity. The volatile elements are those prone to forming covalent chemical bonds. Unlike the metallic or the ionic chemical bonds, the covalent bonds are strictly required for forming the complex molecular structures that may lead to living beings.
So what? The meteorites that fall to Earth were not that size for their entire existence. They are fragments of larger bodies that have collided over the billions of years. Iron meteorites, for example, are remnants of the cores of larger bodies that were big enough to undergo melting and differentiation in the early solar system.
Moreover, "not all places are suitable for OoL, therefore no places are suitable for OoL" would be a non sequitur, so I don't see how what you're trying to say there leads anywhere useful.
Imagine the entire universe contains those buildings block.
Surely you could make this figure be anything you want just by scaling up or down the size of an object you call an asteroid. So as stated it's meaningless.
https://catalina.lpl.arizona.edu/faq/how-often-do-asteroids-...
Actually most water on earth probably came from asteroids, so they are the entire ocean! They would also have brought a lot of frozen methane and ammonia, so most of the chemicals necessary for terrestial life.
When the solar system was forming, the protoplanetary ring of cosmic dust would have consisted of heavy elements (some essential for life, such as phosphorus) closer to the sun and frozen lighter elements further away. The heavy elements would have combined into the early rocky earth, and as the other planets formed and orbits stabilized the icy asteroids from further out would have been flung around and impacted the planets.
One claim, which is likely to be true, is that in the beginning the Earth had a lower content of volatile elements, e.g. hydrogen, nitrogen, carbon, oxygen and sulfur, than today. The reason is that Earth has condensed at a high temperature, being close to the Sun, and those elements would not have condensed.
Later, the Earth has been bombarded by a great number of asteroids formed far from the Sun, which were much richer in H, C, N, O and S, and this bombardment has provided a major part of the chemical elements required for water and for organic substances.
A second, different claim, which is almost certainly false, is that this bombardment of the Earth has provided not only the raw chemical elements, but also pre-synthesized organic substances, like amino-acids and nucleobases, which have taken part directly in the origin of life.
This second claim does not make sense. The meteorites rich in water and organic substances are extremely easily vaporized during atmospheric entry or during the impact with the surface and their content of organic substances would decompose.
Even if we suppose that some falling bodies were so big that parts of them survived until the surface, any organic substances thus brought on Earth could not help in any way the appearance of life.
Any form of life would need a continuous supply of such substances, otherwise immediately after consuming the few molecules adjacent to it the life form would die without descendants.
Life can appear only in a place where there is a continuous supply of energy and it can use only chemical substances that are continuously synthesized in abiotic conditions. It cannot appear based on sporadic events, like the fall of a meteorite, which would also destroy anything at its place of impact.
Such places where energy is available continuously and there are also the substances from which complex organic substances can be synthesized through catalysis by various minerals, mostly metallic sulfides, exist both on Earth and in other places in the Solar System. These are the places where either volcanic gases are released or similar gases are produced by the reaction of water with volcanic rocks, in hydrothermal vents. As far as we know, those are the places where life must have appeared, because all the necessary ingredients exist. The only mysterious part is how it has happened that a correct combination of the mineral catalysts required to synthesize all the needed organic molecules happened to be located in close proximity and in the right sequence.
Today, even if such places still exist on Earth, life could not appear again. First, the oxygen from air would destroy any substances thus formed, and even where oxygen is missing the ubiquitous bacteria would consume any organic substances that could form abiotically, preventing their accumulation and the formation of any kind of structure from them.
Such meteorites fall to Earth even today. Their interiors are often ice cold.
> The missing part is how do they form self-replicating mechanisms capable of evolution.
Well, there are some missing parts, yes, but RNA can self-replicate already; at the least some RNA can. Ribosomes also contain RNA so its is a ribozyme.
That purity is the kind of artificiality I was talking about. A bad habit of OoL research is to show that some chemical shows up in trace amounts, then starting the next stage of experiments with a pure batch of that chemical. Robert Shapiro in his 1986 book "Origins" had some very biting things to say about this (the book is not nice to creationists either, btw.)
https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002...
The article is about a mechanism that may produce random nucleic acid molecules, i.e. molecules that do not replicate any template.
Reactions of this kind, producing random nucleic acids, must have existed long before the appearance of the first self-replicating RNA, thus before the appearance of any nucleic acid that could be inherited by the descendants of a living being and that could provide any useful feature for that living being.
A cynic might suggest the theory might exist because nobody could figure out how life got started on its own on earth.
The thing is I've never found the asteroid theory particularly satisfying either because it simply inserts another abstraction layer, explaining the problem away rather than explaining it.
That's not to say it's wrong but, in its current incarnation, it's just a bit meh.
I suppose perhaps that's part and parcel of it being a very hard problem to solve.
The reason showing abiogenesis is hard is because (1) everything in the biosphere would kill and eat the result and (2) the one thing it had going for it was time - millions of years of random diffusion with nothing else busy executing a grey goo type attack on all the available resources.
Frankly if someone gets abiogenesis to work in a lab environment within a single human lifetime, it wouldn't just be evidence for how it might've happened in Earth's past it would more or less set the parameters for how much life there must be in the universe everywhere because a mere 50 to 100 years to kickstart anything would be insane.
That theory is bullocks. When an asteroid enters the atmosphere and crashes as high speed on the surface, you get a huge amount of energy that creates an explosion and a destruction of most complex chemical material in the process. It's no mistake that these kind of impacts are counted in the same range as multiple atomic or hydrogen bombs.
It fits his overall narrative but it was an interesting way to think about life "as a thermodynamically necessary mechanism to relieve the continuous production of free geochemical energy on Earth... more efficiently than abiotic processes could." (Brannen quoting complex-systems scientist Anne-Marie Grisogono) I highly recommend the book.
I'm no expert but it seems most reasonable to me. The continual talk about pre-biotic soups of ingredients seems profoundly misplaced.
> The five-carbon sugar ribose and, for the first time in an extraterrestrial sample, six-carbon glucose were found.
The soup does matter, as does finding that the ingredients are everywhere.
It doesn't demonstrate the existence of Shakespeare's works, but it's a building block that's good to know exists.
This is absolutely a good finding to have in your pocket.
I would guess there is a more primitive stage in the emergence of life where self-replicating soups (Kaufmann: metabolisms), including things like nucleobases and amino acids, capable of collective replication/expansion exist, before we get anything as sophisticated as nucleic acids and structural encoding.
I assume they have to be ultra clean in every sense of the word 'clean' with the cavity pulled to a vacuum. And also the equipment that collects the sample and puts it into the canister has to be clean as well.
The logistics aren't obvious to me at all
https://phys.org/news/2024-11-ryugu-asteroid-sample-rapidly-...
> Researchers from Imperial College London have discovered that a space-returned sample from asteroid Ryugu was rapidly colonized by terrestrial microorganisms, even under stringent contamination control measures.
https://www.isas.jaxa.jp/en/topics/003899.html
> As described in the discussion of the journal paper, all samples received from JAXA have undergone the initial description, storage, and sealing in dedicated containers under a nitrogen atmosphere. The samples are distributed to researchers without exposure to the Earth's atmosphere. The possibility of microbial contamination is therefore considered extremely low. In addition, organic and microbial contamination assessment of the environment at the curation facilities within JAXA (clean chamber) in which the Ryugu sample grains undergo the initial description are conducted 1 ~ 2 times a year. It has been confirmed and reported that the concentration of organic matter is at or below the same level as that of the OSIRIS-REx asteroid return sample glove box at the NASA Johnson Space Center, and that no microbial colonies have been detected in the microbial contamination assessment conducted with swabbing and culture medium (Yada et al., 2023). Based on these facts, we agree that the microbial contamination described in the paper did not occur during a process within JAXA, but under the laboratory environment of the allocated researchers.
There is nothing magic in RNA or DNA. Granted, right now we can not easily explain how life gets "bootstrapped", but recently there was a paper of self-propagating RNA even of a kind of semi-random sequence; this RNA can just amplify itself. I am sure you can find many more similar examples eventually as well as biochemical reaction processes that can be "bootstrapped" - and I am also sure none of these work on an asteroid. So why is there this strange focus on "life outside of planet Earth"? Some people want research money, that is clear now.
How common the building blocks of life are out in the universe has important implications for open questions like the intersection of the Drake Equation and the Fermi paradox which has likely relevance to our own future here on Earth.
...though I happen to think what we know so far isn't comforting in the sense that the building blocks of life do appear to be very common and the most likely reason that we have to ask "Where is everybody?" in spite of that is that the Great Filter is probably expansionist self-destruction of the sort we are currently speed-running as a society.
Speculation of course, but it would fit a certain historical pattern.
Maybe life is all over the damn place, just a thing that happens under certain thermodynamic constraints, and it arrived on board comets or some similar mechanism.
Maybe space contains spores of minimal super simple organisms that can survive being vacuum freeze dried for incredibly long periods of time. When they land somewhere suitable they do stuff.
Maybe life originated long, long ago. The wildest speculation I have is that it originated shortly after the big bang during a brief period when the temperature of the universe was temperate, but that’s very far fetched for numerous reasons. More likely that it pops up from time to time and spreads over cosmic time scales.
But it only evolves to high levels of complexity in environments that are very friendly to a lot of life, have abundant energy, and are stable enough for a very long time. That may be the rare thing.
Sub-Surface Sample: The sub-surface sample collection required an impactor to create a crater in order to retrieve material under the surface, not subjected to space weathering. This required removing a large volume of surface material with a powerful impactor. For this purpose, Hayabusa2 deployed on 5 April 2019 a free-flying gun with one "bullet", called the Small Carry-on Impactor (SCI); the system contained a 2.5 kg (5.5 lb) copper projectile, shot onto the surface with an explosive propellant charge. Following SCI deployment, Hayabusa2 also left behind a deployable camera (DCAM3)[Note 1] to observe and map the precise location of the SCI impact, while the orbiter maneuvered to the far side of the asteroid to avoid being hit by debris from the impact.
It was expected that the SCI deployment would induce seismic shaking of the asteroid, a process considered important in the resurfacing of small airless bodies. However, post-impact images from the spacecraft revealed that little shaking had occurred, indicating the asteroid was significantly less cohesive than was expected.[76]
Duration: 36 seconds.0:36 The touchdown on and sampling of Ryugu on 11 July Approximately 40 minutes after separation, when the spacecraft was at a safe distance, the impactor was fired into the asteroid surface by detonating a 4.5 kg (9.9 lb) shaped charge of plasticized HMX for acceleration.[56][77] The copper impactor was shot onto the surface from an altitude of about 500 m (1,600 ft) and it excavated a crater of about 10 m (33 ft) in diameter, exposing pristine material.[15][32] The next step was the deployment on 4 June 2019 of a reflective target marker in the area near the crater to assist with navigation and descent.[33] The touchdown and sampling took place on 11 July 2019.[34]
Or like some ancient alien species that travelled the stars but found it was alone, like in the ST:TNG episode[0]? No too.
Even if these ancient aliens thought it would be fun to spread their sperm all over asteroids and fling them out into the universe, there wouldn't be enough time for those rocks to get anywhere.
The more logical conclusion is that abiogenesis happens everywhere in the universe under the right conditions.
[0]: https://en.wikipedia.org/wiki/The_Chase_(Star_Trek:_The_Next...
The only thing left to figure out is how did these legos learn to assemble themselves.
I mean, even if the starting state require to bootstrap life have impossibly low chance to happen random, multi-world interpretation implies that there will be some worlds where it happened, and observation of life is only possible in such worlds..
But I don't think we are "lucky", because we are part of the world, not something that was placed inside it by choice. It is like asking why is Nile in Egypt and not in some other place. If Nile is in some other place, it would not be Nile...So does it make sense to say that Nile is lucky to be in Egypt? No, I think it does not make sense...
I won't comment further unless you offer a convincing proof of your assertion.
If this is the question, I think the Multi Worlds Interpretation provides the answer. Because it says that there is some worlds where any given random event will manifest.
So it follows that there is some worlds, where this random event that we call the "origin of life" manifested. And it is just that we are part of one such world.
>multiworld interpretation is one of several interpretations of quantum mechanics of the exact same evidence
I think we might think the other way around. That the origin of life, as well as the fact that we seem to be alone in the universe, as a proof of the MWI..
About the latter, I think we have an overwhelming chance to be alone, because while it is true that there can be universes where random events have lead to origin of life in multiple places, the universes where there is only a single "origin of life" event will vastly outnumber such universes that the chances of us finding oursleves in one such universe (where life has originated independently more than once) is vanishingly small.
https://www.science.org/doi/10.1126/science.abn9033
In the reference from the link for this HN entry, we see the nucleobases were present at concentrations of about 1 nano-mole per gram (< 1 ppm). They are minor constituents present in a sea of mostly non-biologically relevant compounds.