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Ryugu asteroid samples contain all DNA and RNA building blocks

phys.org

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Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#11

Post by ceejayoz »

fusslo wrote: post #9

I wonder how they prevent contamination of the containers used to collect and store samples. 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

They seem pretty confident. There's been some conflicting reporting on contamination of the Ryugu samples over time.

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.

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#12

Post by ceejayoz »

pfdietz wrote: post #7
ceejayoz wrote: post #4

Earlier quoted context omitted.

https://www.nasa.gov/missions/osiris-rex/sugars-gum-stardust... > 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.

Finding exponentially decreasing amounts of specific chemicals is about as informative as finding short words in strings of random letters.

Finding short words in strings of random letters at least establishes the existence of letters and words.

It doesn't demonstrate the existence of Shakespeare's works, but it's a building block that's good to know exists.

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#13

Post by HarHarVeryFunny »

pfdietz wrote: post #2

It contains nucleobases. But does it contain ribose, or ribose linked to the nucleobases, or to phosphates? And more generally, does it also contain a grab bag of related chemicals that are not building blocks? The existence of such blocks as minor constituents of a soup of random chemicals doesn't mean much, especially as the concentration of any such constituent declines exponentially with its complexity.

It's a sample of one, but I think the takeaway is just that if the nucleobases are present on a random asteroid then they probably commonly occur. Of course as you note it takes a lot more than that to form these into nucleic acids.

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.

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#14

Post by bookofjoe »

fusslo wrote: post #9

I wonder how they prevent contamination of the containers used to collect and store samples. 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://science.gsfc.nasa.gov/sed/content/uploadFiles/public...

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#15

Post by 0x000xca0xfe »

starburst wrote: post #10
0x000xca0xfe wrote: post #8

One longstanding theory is that life first began on Earth when asteroids carrying fundamental elements crashed into our planet long ago. I'm no expert but this sounds strange. Surely those fundamental elements would also form in vast quantities on their own on an entire planet with volcanoes and oceans? Wouldn't a couple asteroids be the literal drop in the ocean in comparison? The missing part is how do they form se…

Well the competition might be too fierce for any new life to develop

We could artificially create a sterile, large pool of the ingredients and see what happens.

I've read about experiments like this but only at lab beaker scale.

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#16

Post by pfdietz »

ceejayoz wrote: post #12
pfdietz wrote: post #7

Earlier quoted context omitted.

Finding exponentially decreasing amounts of specific chemicals is about as informative as finding short words in strings of random letters.

Finding short words in strings of random letters at least establishes the existence of letters and words. It doesn't demonstrate the existence of Shakespeare's works, but it's a building block that's good to know exists.

All it means is you can say "if life is rare, it's not because these specific small chemicals can't be produced". Which is a rather weak thing to say. It doesn't imply life isn't rare, or that further advancement the existence of these small building blocks is easy or inevitable.

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#17

Post by ceejayoz »

pfdietz wrote: post #16
ceejayoz wrote: post #12

Earlier quoted context omitted.

Finding short words in strings of random letters at least establishes the existence of letters and words. It doesn't demonstrate the existence of Shakespeare's works, but it's a building block that's good to know exists.

All it means is you can say "if life is rare, it's not because these specific small chemicals can't be produced". Which is a rather weak thing to say. It doesn't imply life isn't rare, or that further advancement the existence of these small building blocks is easy or inevitable.

> All it means is you can say "if life is rare, it's not because these specific small chemicals can't be produced".

This is absolutely a good finding to have in your pocket.

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#18

Post by HarHarVeryFunny »

0x000xca0xfe wrote: post #8

One longstanding theory is that life first began on Earth when asteroids carrying fundamental elements crashed into our planet long ago. I'm no expert but this sounds strange. Surely those fundamental elements would also form in vast quantities on their own on an entire planet with volcanoes and oceans? Wouldn't a couple asteroids be the literal drop in the ocean in comparison? The missing part is how do they form se…

I guess it depends on how you define life, and whether we'd even recognize it when we see it, assuming we're looking in the right places.

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.

Re: Ryugu asteroid samples contain all DNA and RNA building blocks

#20

Post by fusslo »

bookofjoe wrote: post #14
fusslo wrote: post #9

I wonder how they prevent contamination of the containers used to collect and store samples. 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://science.gsfc.nasa.gov/sed/content/uploadFiles/public...

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