6 ms·

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 nucle

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" https://www.nature.com/articles/s41467-023-36904-3 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

f6v 4y ago
> For having RNA you need a molecule composed of roughly 200 nucleotides. miRNA are order of magnitude smaller.
- CrispCas13 4y ago
  That's after DICER/Drosha processes the pre-miRNA/pri-miRNA transcripts. The pre-miRNA/pri-miRNAs transcripts can be a magnitude equal to or greater than 200 nts.
wheelerof4te 4y ago
I would guess that whatever organic molecule was on that asteroid, it died off from the intense radiation in space.
- b1c1jones 4y ago
  Organic doesn't necessarily imply living.
  - faeyanpiraat 4y ago
    It actually does: "Organic: relating to or derived from living matter"
    - dsr_ 4y ago
      This is the difference between standard usage and jargon. Chemists consider any covalent compound involving carbon that isn't only carbon to be "organic". Normal usage is what you wrote. Alternative but widespread usage is "agricultural products made without synthesized fertilizers and pesticides". Oh, and business jargon uses organic to mean "natural market growth or internally developed capabilities", as opposed to buying the growth or capability. And in military usage, organic means "a permanently assigned assisting unit", so that routine vehicle maintenance, for example, is handled by people who travel with the vehicle.
      - mr_mitm 4y ago
        It's like astronomer talking about metals. By which they mean everything that's not hydrogen or helium.
        kortex 4y ago
        To their credit, I remember something about basically every element ionizes to some extent in space, thus exhibiting the "sea of electrons" behavior characteristic of metals.
        JumpCrisscross 4y ago
        > like astronomer talking about metals This is particular to stellar astrophysics. Astronomers studying asteroids maintain the conventional definition.
      - prewett 4y ago
        I've taken to using "organic-branded" for the agricultural products, since "organic" is essentially an FDA brand, with regulations for usage of the branding. Its also my personal rebellion against "organic" having a functional meaning of "magicalhealthygoodness" in some circles.
    - gilleain 4y ago
      Yes, /originally/ 'Organic' meant from living matter. However, when it was discovered that urea could be synthesised in the lab, we realised that there was no real distinction between 'living' molecules and 'dead' ones ... Nowadays, 'organic' refers to chemicals with a majority (?) carbon content. It gets a little tricky for things like diamond and graphene (both materials) or for compounds that have a lot of heteroatoms. Oddly enough, another nucleotide base (adenine) is exactly 50:50 C:N and has been proved to be synthesised from just HCN. So is it 'half'organic' :)
- eimrine 4y ago
  What kind of intense radiation is needed to kill a molecule of teflon?
jasonlotito 4y ago
> They didn't detect RNA which would be extraordinary. 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.
- chatmasta 4y ago
  As someone who reads the comments more than the articles, I always appreciate when this kind of clarification is in the comments. It's one of the best parts of HN.
  - nabakin 4y ago
    I appreciate it too
  - maicro 4y ago
    Honestly, me too, to the point where I open the comments in tabs before visiting the articles. It may be biased, but seeing what the HN hivemind has to say about the topic is usually as valuable, and often more valuable, than the linked article itself. There are also situations like this one where, while I find the headline interesting, I don't care enough to read through the whole link - so I'll check the comments for any significant additions or corrections or clarifications, and sometimes read the interesting discussions that occur, but won't even click through to the main link. It might come down to a question of number of perspectives - the linked article is usually by a single person/group (or worse, a news org poorly interpreting the results of a group), while the HN comment section will be filled with a variety of people, often with domain specific knowledge and experience. All that to say, HN is an interesting community, and I don't think there's a "wrong" way to interact with/be part of it (as long as you're being respectful etc.).
- adrianmonk 4y ago
  The point is that the headline is ambiguous. RNA is a compound, and Uracil is also a compound. Thus you cannot tell from just the words "RNA compound" whether they mean a compound that is RNA or a compound that is part of RNA.
dekhn 4y ago
not even a nucleotide- just a nucleobase. It's missing the ribose sugar so it can't form polymers.
deleted 4y ago
[deleted]
exyi 4y ago
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...)
- dekhn 4y ago
  RNA can be stable if it's dry but DNA is much more stable. I can't see DNA surviving undamaged on the surface of an asteroid, but I could see: DNA getting somehow embedded in a rock agglomerate, then the rock gets ejected from a planet, lands on another planet whole, and then the rock breaks and now you have dna on another planet. With enough deep time, this could occur (possibly) but I can't see it as an effective method. instead, better to take tardigrades, induce tun state, embed that in rock, and let that float around for a while. They have pretty much everything needed to survive including safe storage for DNA, DNA repair enzymes, redundant DNA, radiation-resistant exterior, etc.
JumpCrisscross 4y ago
> if we find RNA, it would be very indicative of DNA Or evidence for the RNA world hypothesis [1]. [1] https://en.m.wikipedia.org/wiki/RNA_world https://en.m.wikipedia.org/wiki/RNA_world

f6v 4y ago

> For having RNA you need a molecule composed of roughly 200 nucleotides. miRNA are order of magnitude smaller.

CrispCas13 4y ago
That's after DICER/Drosha processes the pre-miRNA/pri-miRNA transcripts. The pre-miRNA/pri-miRNAs transcripts can be a magnitude equal to or greater than 200 nts.

wheelerof4te 4y ago

I would guess that whatever organic molecule was on that asteroid, it died off from the intense radiation in space.

b1c1jones 4y ago
Organic doesn't necessarily imply living.
- faeyanpiraat 4y ago
  It actually does: "Organic: relating to or derived from living matter"
  - dsr_ 4y ago
    This is the difference between standard usage and jargon. Chemists consider any covalent compound involving carbon that isn't only carbon to be "organic". Normal usage is what you wrote. Alternative but widespread usage is "agricultural products made without synthesized fertilizers and pesticides". Oh, and business jargon uses organic to mean "natural market growth or internally developed capabilities", as opposed to buying the growth or capability. And in military usage, organic means "a permanently assigned assisting unit", so that routine vehicle maintenance, for example, is handled by people who travel with the vehicle.
    - mr_mitm 4y ago
      It's like astronomer talking about metals. By which they mean everything that's not hydrogen or helium.
      - kortex 4y ago
        To their credit, I remember something about basically every element ionizes to some extent in space, thus exhibiting the "sea of electrons" behavior characteristic of metals.
      - JumpCrisscross 4y ago
        > like astronomer talking about metals This is particular to stellar astrophysics. Astronomers studying asteroids maintain the conventional definition.
    - prewett 4y ago
      I've taken to using "organic-branded" for the agricultural products, since "organic" is essentially an FDA brand, with regulations for usage of the branding. Its also my personal rebellion against "organic" having a functional meaning of "magicalhealthygoodness" in some circles.
  - gilleain 4y ago
    Yes, /originally/ 'Organic' meant from living matter. However, when it was discovered that urea could be synthesised in the lab, we realised that there was no real distinction between 'living' molecules and 'dead' ones ... Nowadays, 'organic' refers to chemicals with a majority (?) carbon content. It gets a little tricky for things like diamond and graphene (both materials) or for compounds that have a lot of heteroatoms. Oddly enough, another nucleotide base (adenine) is exactly 50:50 C:N and has been proved to be synthesised from just HCN. So is it 'half'organic' :)
eimrine 4y ago
What kind of intense radiation is needed to kill a molecule of teflon?

jasonlotito 4y ago

> They didn't detect RNA which would be extraordinary. 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.

chatmasta 4y ago
As someone who reads the comments more than the articles, I always appreciate when this kind of clarification is in the comments. It's one of the best parts of HN.
- nabakin 4y ago
  I appreciate it too
- maicro 4y ago
  Honestly, me too, to the point where I open the comments in tabs before visiting the articles. It may be biased, but seeing what the HN hivemind has to say about the topic is usually as valuable, and often more valuable, than the linked article itself. There are also situations like this one where, while I find the headline interesting, I don't care enough to read through the whole link - so I'll check the comments for any significant additions or corrections or clarifications, and sometimes read the interesting discussions that occur, but won't even click through to the main link. It might come down to a question of number of perspectives - the linked article is usually by a single person/group (or worse, a news org poorly interpreting the results of a group), while the HN comment section will be filled with a variety of people, often with domain specific knowledge and experience. All that to say, HN is an interesting community, and I don't think there's a "wrong" way to interact with/be part of it (as long as you're being respectful etc.).
adrianmonk 4y ago
The point is that the headline is ambiguous. RNA is a compound, and Uracil is also a compound. Thus you cannot tell from just the words "RNA compound" whether they mean a compound that is RNA or a compound that is part of RNA.

dekhn 4y ago

not even a nucleotide- just a nucleobase. It's missing the ribose sugar so it can't form polymers.

deleted 4y ago

[deleted]

exyi 4y ago

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...)

dekhn 4y ago
RNA can be stable if it's dry but DNA is much more stable. I can't see DNA surviving undamaged on the surface of an asteroid, but I could see: DNA getting somehow embedded in a rock agglomerate, then the rock gets ejected from a planet, lands on another planet whole, and then the rock breaks and now you have dna on another planet. With enough deep time, this could occur (possibly) but I can't see it as an effective method. instead, better to take tardigrades, induce tun state, embed that in rock, and let that float around for a while. They have pretty much everything needed to survive including safe storage for DNA, DNA repair enzymes, redundant DNA, radiation-resistant exterior, etc.

JumpCrisscross 4y ago

> if we find RNA, it would be very indicative of DNA Or evidence for the RNA world hypothesis [1]. [1] https://en.m.wikipedia.org/wiki/RNA_world https://en.m.wikipedia.org/wiki/RNA_world