They didn't detect RNA which would be extraordinary. What they detected is Uracil, one of the molecules that is found in RNA.
They didn't found any other nucleotides.
"Other DNA/RNA nucleobases were not positively identified in both the A0106 and C0107 samples. This does not necessarily exclude a possibility that those nucleobases are present in the Ryugu samples, but just they may be below the detection limit under the experimental conditions employed"
For having RNA you need a molecule composed of roughly 200 nucleotides. If we find RNA, it would be very indicative of DNA, so of living beings very similar to us
If it had 200 nucleotides you'd know for sure it's a contamination. RNA isn't very stable (in our conditions, I have no idea how it does at 3 Kelvin, blasted with radiation for a million years...)
>“Since the Hayabusa2 spacecraft collected two samples directly from asteroid Ryugu and delivered them to Earth in sealed capsules, contamination can be ruled out.”
I seriously doubt that it could be "ruled out" just like that.
For one, the spacecraft (or the empty capsules) could have been pre-contaminated before their launch.
Second, the capsules could have been contaminated after arrival even if they were "sealed" (perhaps the seal had issues, or maybe it happened when they opened them, since one assumes they couldn't test still sealed capsules, they'd have to open them).
It would be a little weird for it to be contaminated with only uracil. Sure, if they found full RNA strands you'd start to think contamination was more likely, but what are the odds it was contaminated but with only uracil, especially considering how far they've gone to prevent contamination?
I wonder if there's a "control group": a tiny but identical container that goes through all the same steps. Nothing can ever be proof that it wasn't contaminated or a seal was broken on the real but not the control container, like, nothing will convince an Internet conspiracy theorist, but a control vessel and a handful such missions ought to prove beyond reasonable doubt that it wasn't contaminated from earth. I'm personally already willing to trust that they thought of (and controlled for) these things and more, since it's their job and we're just thinking out loud here.
> For one, the spacecraft (or the empty capsules) could have been pre-contaminated before their launch.
I had a really interesting discussion with someone who oversaw decontamination protocols and preparations for various satellites, including the JWST. The protocols they use to prep satellites for these types of missions are beyond stringent, and the chemicals they use are exotic as all hell.
All this to say, contamination is absolutely possible, but there is so much insane behind the scenes work to control for it that it shouldn’t be thought of as something they might “just forget” or casually missed.
“Scientists have previously found nucleobases and vitamins in certain carbon-rich meteorites, but there was always the question of contamination by exposure to the Earth’s environment,” said lead study author Yasuhiro Oba, associate professor at Hokkaido University in Japan, in a statement. “Since the Hayabusa2 spacecraft collected two samples directly from asteroid Ryugu and delivered them to Earth in sealed capsules, contamination can be ruled out.”
In other words, there is a history of finding similar compounds on meteorites but under circumstances that made it iffy, at best, to assert these compounds came from space. In spite of debate in comments on HN, this sample constitutes stronger support than we previously had for the idea that these compounds really exist on meteorites in space.
The thing I was hoping to see in the comments is discussion around the complexity of these compounds and thus how likely they are to form abiotic.
Looking at vitamin b3, it seems very simple.
My take away is more that the chemistry of life as we know it is pretty prevalent and probably forms readily under many circumstances. I am not shocked this wasn’t an actual DNA strand. Even if someone left some DNA out on an asteroid over enough time I expect it would deteriorate. The universe just bombards stuff without an atmosphere too much for naked DNA to survive in those conditions.
This is basically the biggest success I could rationally hope for from this probe. Great work for those scientists and I am so amazed!
This has gotta add weight to the Panspermia hypothesis.
Panspermia is a hypothesis that suggests life on Earth may have originated from microorganisms or organic matter that traveled through space, potentially from other planets or moons in our solar system or even from other star systems.
The opposite. If such compounds are common in asteroids absent life, then the rise of RNA/DNA on different planets is more likely to be happening spontaneously, without anything traveling between planets. This finding suggests that some building blocks of life may be very common, increasing the chances of life arising locally without need of panspermia.
Rather, IMHO, it gives us more information on how the conditions on Earth might have been when life emerged. We're getting more and more clues that a lot of the basic blocks of life are present in asteroids and thus might have been present on the primordial Earth as well in some watery soup where life emerged.
That’s a cope, not an explanation. It’s like saying “God made the world”. It doesn’t answer the question because then the question is who made God.
If your theory relies on external creation on another planet or whatever, then it’s meaningless because how did life start there. If life could start there then it could have started here so why do we need your theory at all?
"The Japanese Aerospace Exploration Agency mission collected one sample from the asteroid’s surface in February 2019, then fired a copper 'bullet' into the asteroid to create a 33-foot (10-meter) wide impact crater."
10 meters seems like a pretty impressive crater for a science payload launched from a deep space probe. In case anyone else is curious, there's a detailed writeup[1] about the Small Carry-on Impactor (SCI) that was used.
It looks a little bit like a swords-into-plowshares version of a HEAT warhead. A shaped plastic explosive charge simultaneously launched and deformed a copper plate so that by the time it hit the asteroid, the projectile was shaped like a hollow bullet. ~2kg moving at ~2km/sec, so about 4 million Joules, or about 200 times the kinetic energy of a .50 BMG round. That's some bullet!
Given infinite time you would expect any pool of materials to eventually wibble together into certain compounds. Those compounds will wibble infinitely until they create structures. Some of those structures will be able to wibble compounds together. Some of those structures will be an exact copy of the structure that made it. Those structures will then replicate.
Simple life seems inevitable. It’s the tiers above that are the hard part. We only have mitochondria because we ate them and forced them to reproduce inside of us. Without that we would probably have never got beyond the single cell level. There’s a lot of random developments that we could have missed and ended up as just slime on a rock for eternity.
It's my understanding that the RNA world hypothesis is pretty much widely accepted these days anyway. The open question is more how you get to the RNA world in the first place. The RNA hypothesis as such is more an hypothesis of what preceded life based on DNA and protein, and less so a theory of the origin of life from non-life per se.
The two main camps today seem to be "metabolism first" with people like Nick Lane and "genetics first" with people like Jack Szostack.
I used to favour the genetics side but I've been leaning more towards metabolism recently. Lane's research on this has been fascinating.
I read Hoyle and Wikiramasingh's books back in the late 70s and 80s. Fun reads and thought-provoking no matter what side you fall on the Panspermia argument. To those who downplay it as not really being RNA, this is one mission to a near-Earth asteroid. What are the odds you would even find a nucleobase? Amazing work and the contamination argument is always presented in light of any such discoveries. There was also the dismissal of fossil-like impressions in meteorites cut open as just looking like a known life form. I WANT TO BELIEVE ;)
'''revealing that a wide range of organic compounds such as racemic non-protein type amino acids, alkylamines, carboxylic acids, polycyclic aromatic hydrocarbons (PAHs), and nitrogen heterocyclic molecules are present in the aqueous or organic extracts'''
from the linked paper.
racemic mix refers to the equal amout of stereoisomers
[+] [-] JPLeRouzic|3 years ago|reply
They didn't found any other nucleotides.
"Other DNA/RNA nucleobases were not positively identified in both the A0106 and C0107 samples. This does not necessarily exclude a possibility that those nucleobases are present in the Ryugu samples, but just they may be below the detection limit under the experimental conditions employed"
https://www.nature.com/articles/s41467-023-36904-3
For having RNA you need a molecule composed of roughly 200 nucleotides. If we find RNA, it would be very indicative of DNA, so of living beings very similar to us
[+] [-] dekhn|3 years ago|reply
[+] [-] JumpCrisscross|3 years ago|reply
Or evidence for the RNA world hypothesis [1].
[1] https://en.m.wikipedia.org/wiki/RNA_world
[+] [-] f6v|3 years ago|reply
miRNA are order of magnitude smaller.
[+] [-] exyi|3 years ago|reply
[+] [-] jasonlotito|3 years ago|reply
Correct, and they don't say that. They found an RNA compound. Uracil, one of the molecules that is found in RNA.
Not sure of the purpose of this comment to regurgitate what's found in the article itself, which goes into greater detail.
[+] [-] unknown|3 years ago|reply
[deleted]
[+] [-] wheelerof4te|3 years ago|reply
[+] [-] coldtea|3 years ago|reply
I seriously doubt that it could be "ruled out" just like that.
For one, the spacecraft (or the empty capsules) could have been pre-contaminated before their launch.
Second, the capsules could have been contaminated after arrival even if they were "sealed" (perhaps the seal had issues, or maybe it happened when they opened them, since one assumes they couldn't test still sealed capsules, they'd have to open them).
[+] [-] roywiggins|3 years ago|reply
[+] [-] Aachen|3 years ago|reply
[+] [-] Cardinal7167|3 years ago|reply
I had a really interesting discussion with someone who oversaw decontamination protocols and preparations for various satellites, including the JWST. The protocols they use to prep satellites for these types of missions are beyond stringent, and the chemicals they use are exotic as all hell.
All this to say, contamination is absolutely possible, but there is so much insane behind the scenes work to control for it that it shouldn’t be thought of as something they might “just forget” or casually missed.
[+] [-] fnordpiglet|3 years ago|reply
https://earth-planets-space.springeropen.com/articles/10.118...
[+] [-] b1c1jones|3 years ago|reply
https://earth-planets-space.springeropen.com/articles/10.118...
[+] [-] aa-jv|3 years ago|reply
[deleted]
[+] [-] DoreenMichele|3 years ago|reply
In other words, there is a history of finding similar compounds on meteorites but under circumstances that made it iffy, at best, to assert these compounds came from space. In spite of debate in comments on HN, this sample constitutes stronger support than we previously had for the idea that these compounds really exist on meteorites in space.
[+] [-] ianai|3 years ago|reply
Looking at vitamin b3, it seems very simple.
My take away is more that the chemistry of life as we know it is pretty prevalent and probably forms readily under many circumstances. I am not shocked this wasn’t an actual DNA strand. Even if someone left some DNA out on an asteroid over enough time I expect it would deteriorate. The universe just bombards stuff without an atmosphere too much for naked DNA to survive in those conditions.
This is basically the biggest success I could rationally hope for from this probe. Great work for those scientists and I am so amazed!
[+] [-] schappim|3 years ago|reply
Panspermia is a hypothesis that suggests life on Earth may have originated from microorganisms or organic matter that traveled through space, potentially from other planets or moons in our solar system or even from other star systems.
[+] [-] sandworm101|3 years ago|reply
[+] [-] mytailorisrich|3 years ago|reply
Rather, IMHO, it gives us more information on how the conditions on Earth might have been when life emerged. We're getting more and more clues that a lot of the basic blocks of life are present in asteroids and thus might have been present on the primordial Earth as well in some watery soup where life emerged.
[+] [-] FollowingTheDao|3 years ago|reply
But where did the microorganisms on the asteroid come from?
[+] [-] MagicMoonlight|3 years ago|reply
If your theory relies on external creation on another planet or whatever, then it’s meaningless because how did life start there. If life could start there then it could have started here so why do we need your theory at all?
[+] [-] mromanuk|3 years ago|reply
[+] [-] andrewstuart|3 years ago|reply
Crunchy rocks of breakfast cereal from the depths of space!
Delicious with cold milk.
Fortified with RNA compound and vitamin B3.
No added complex organic molecules.
[+] [-] spontanious|3 years ago|reply
[+] [-] blincoln|3 years ago|reply
10 meters seems like a pretty impressive crater for a science payload launched from a deep space probe. In case anyone else is curious, there's a detailed writeup[1] about the Small Carry-on Impactor (SCI) that was used.
It looks a little bit like a swords-into-plowshares version of a HEAT warhead. A shaped plastic explosive charge simultaneously launched and deformed a copper plate so that by the time it hit the asteroid, the projectile was shaped like a hollow bullet. ~2kg moving at ~2km/sec, so about 4 million Joules, or about 200 times the kinetic energy of a .50 BMG round. That's some bullet!
[1] https://www.planetary.org/articles/what-to-expect-hayabusa2-...
[+] [-] MagicMoonlight|3 years ago|reply
Simple life seems inevitable. It’s the tiers above that are the hard part. We only have mitochondria because we ate them and forced them to reproduce inside of us. Without that we would probably have never got beyond the single cell level. There’s a lot of random developments that we could have missed and ended up as just slime on a rock for eternity.
[+] [-] cft|3 years ago|reply
[+] [-] mtlmtlmtlmtl|3 years ago|reply
The two main camps today seem to be "metabolism first" with people like Nick Lane and "genetics first" with people like Jack Szostack.
I used to favour the genetics side but I've been leaning more towards metabolism recently. Lane's research on this has been fascinating.
[+] [-] eggy|3 years ago|reply
[+] [-] deepzn|3 years ago|reply
[+] [-] jeroenvlek|3 years ago|reply
[+] [-] jbj|3 years ago|reply
'''revealing that a wide range of organic compounds such as racemic non-protein type amino acids, alkylamines, carboxylic acids, polycyclic aromatic hydrocarbons (PAHs), and nitrogen heterocyclic molecules are present in the aqueous or organic extracts'''
from the linked paper.
racemic mix refers to the equal amout of stereoisomers
[+] [-] m3kw9|3 years ago|reply
[+] [-] hulitu|3 years ago|reply
They can start mining asteroids for vitamins. /s
[+] [-] pfdietz|3 years ago|reply
[+] [-] hdhrufjdi|3 years ago|reply