Sugars, 'Gum,' Stardust Found In NASA's Asteroid Bennu Samples (nasa.gov) 42
NASA's OSIRIS-REx samples from asteroid Bennu have revealed bio-essential sugars, a never-before-seen "space gum" polymer, and unusually high levels of supernova-origin dust. The findings bolster the RNA-world hypothesis, suggest complex organics formed early on Bennu's parent body, and show preserved presolar grains that escaped alteration for billions of years.
"All five nucleobases used to construct both DNA and RNA, along with phosphates, have already been found in the Bennu samples brought to Earth by OSIRIS-REx," said lead scientist Yoshihiro Furukawa of Tohoku University. "The new discovery of ribose means that all of the components to form the molecule RNA are present in Bennu."
The findings have been published in three new papers by the journals Nature Geosciences and Nature Astronomy. NASA also published a video on YouTube detailing the discovery.
"All five nucleobases used to construct both DNA and RNA, along with phosphates, have already been found in the Bennu samples brought to Earth by OSIRIS-REx," said lead scientist Yoshihiro Furukawa of Tohoku University. "The new discovery of ribose means that all of the components to form the molecule RNA are present in Bennu."
The findings have been published in three new papers by the journals Nature Geosciences and Nature Astronomy. NASA also published a video on YouTube detailing the discovery.
I'm not saying we're aliens (Score:4, Funny)
But that's my great great great grandpa.
Re:I'm not saying we're aliens (Score:4, Interesting)
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Read my other comment.
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Re: I'm not saying we're aliens (Score:2, Funny)
Life is extremely improbable (Score:2, Interesting)
All life on Earth has a common origin. This is easily provable --- we all have nearly the same ribosome sequence. No organisms have ever been found with a wildly different ribosome code (let alone different molecular/genetic system). It's virtually impossible for that to happen unless life emergence was EXTREMELY improbable and we got super lucky. Not unless there's only one way to make a ribosome ... which too is a provably ridiculous and incorrect assertion. Now how the hell is that? It means no other mec
Re:Life is extremely improbable (Score:5, Insightful)
LUCA's descendants were able to go to every possible life niche on Earth and displace all other types of life? That makes very little sense.
It makes perfect sense, you explained clearly how it could happen.
The reasonable way of looking at it is, "What is the probability of that happening?" That's a scientific question.
Re:Life is extremely improbable (Score:4, Funny)
The reasonable way of looking at it is, "What is the probability of that happening?" That's a scientific question.
That's easy, 50/50. It either did or it didn't.
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"Not unless there's only one way to make a ribosome ... which too is a provably ridiculous and incorrect assertion."
But there may have been an optimal ribosome for the conditions at the time, and even in disparate populations that one optimal (or a close enough version of it, the word "nearly" is doing a lot of work in your post) could have displaced all other versions, until the initially separate populations merged and created the consistency in origin we see today.
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No. The mapping of nucleotide sequences onto amino acids isn't predetermined. We've built in the labs versions that are different.
OTOH, the argument still isn't good. It could be a low, but not extremely low, probability. In that case the first one to show up could have a VERY strong advantage. And we haven't checked all life on Earth, so the assertion that they are all the same hasn't really been proven, either.
We are pretty certain that the appearance of life involved some very low probability events
Re:Life is extremely improbable (Score:5, Insightful)
Bro, that sound plausible to you? Think about what you're saying .. LUCA's descendants were able to go to every possible life niche on Earth and displace all other types of life? That makes very little sense.
It actually makes a lot of sense to me for the simple fact that expanding into new niches is generally going to require evolving through natural selection to be able to thrive in that niche. Also because, to my knowledge, we have not found any niches anywhere on Earth without life as we know it that are not under such extreme conditions that it is unlikely for other forms of life to stand a chance.
I am not saying that other versions of life have definitely developed on Earth before. I am simply saying that, if they had, they would clearly have been out-competed by life as we know it both due to first-mover advantage and because, as we can see from the results from the Bennu samples, the building blocks of life as we know it clearly have their own survival advantage. Ultimately, any form of life is going to concentrate energy and those kinds of concentrations of energy are going to be food for more evolved and more capable forms of life.
So, while most of what you are saying is correct, if you are asserting that no other form of life could exist or have ever arisen on Earth, you clearly do not have the data to prove that.
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Think about what you're saying .. LUCA's descendants were able to go to every possible life niche on Earth and displace all other types of life? That makes very little sense.
That is what I think happened. It took some time (millions of years) for LUCA to emerge, once it did it would have quickly spread across the planet, quickly being more millions of years. LUCA would have evolved, some being fitter than others: faster, more robust metabolism - these would have out competed less fit LUCA descendants and also non LUCA that was getting going.
That is not to say that non LUCA descendants do not exist in some niche somewhere - but we have not seen them - yet. So apply Occam's razor [wikipedia.org]
Re:Life is extremely improbable (Score:5, Informative)
It's not that life is improbable, it's that the first mover has too big of an advantage. Darwin famously said something about if new life emerged today from "primordial soup", it would just get eaten before it even had a chance.
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It would even get close to emerging. Free floating RNA and DNA precursors + fatty acids are a tasty lunch to a lot of microorganisms.
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Those are descendants of LUCA. A better question would be viruses, because in that case we don't really know. (There aren't any ribosomes. [OTOH, if there are descendants of another origin, they've massively adapted.])
OTOH, we haven't checked all life on earth. So assertions about universals should be viewed with that in mind.
Are the samples representative? (Score:1)
Whenever I hear that sample x shows y, my first question is how representative is the sample?
Things like how was the sample taken, sample container specification, handling of the sample and the list goes on.
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I agree, we have to read the papers wherein they published their protocols and also trust the scientists did procedures as specified and everyone handled things with high skepticism. I assume they had a control container that came back with the capsule that had non-Bennu asteroid simulant in order to verify their cleanliness procedures.
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I shared the link for a paper referenced within the main paper about the design of the sampling facility https://onlinelibrary.wiley.co... [wiley.com]
Nasa wasting money again (Score:4, Funny)
In these harsh economic times it is disgusting to see NASA once again wasting taxpayers money by making asteroids out of sugar when HFCS is much cheaper.
Re: Nasa wasting money again (Score:2)
And stardust and gum. Sounds like someone has been throwing parties with tax dollars.
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Hi from Australia. Have you never tasted QLD cane sugar?
American Coke tastes horrible.
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Hi from Australia. Have you never tasted QLD cane sugar?
American Coke tastes horrible.
FWIW, there's a lot more to it than that. Here's some good info on it: https://www.youtube.com/watch?... [youtube.com]
Some points from that:
* Sugar (sucrose) in an acid will quickly be split into Fructose and Glucose (about 50/50 ratio).
* Mexican Coke tested with near zero sucrose content (it had split).
* Corn Syrup is nearly the same ratio of Fructose and Glucose (about 55/42 ratio).
* No, you can't taste the difference between those sugars.
* Mexican Coke had nearly twice the sodium... something you can taste.
I thought I
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As the saying goes (Score:2)
There are those who believe that life here began out there.
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Well, panspermia is possible, but not extremely likely. OTOH, if life started on Mars, it could well have spread to Earth on impact debris. The further away, the less likely. But remember that yeast have survived in space conditions for months, perhaps years...and that wasn't in extreme cold (though it was in inactive form).
OTOH, years is different from centuries. And for interstellar trips in a comet, centuries wouldn't be enough.
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Do you really think fiction is a reasonable source of facts?
doesn't answer the more important questions... (Score:1)
"All five nucleobases" (Score:3)
This threw me for a loop - I was not aware of more than 4 and had to check on that.
Turns out the 5th isn't really the fifth, it's cytosine with an added methyl group attached and there are actually two variants:
5-methylcytosine (5-mC)
5-hydroxymethylcytosine (5-hmC)
So I'm sticking to my original understanding of DNA/RNA that it consists of only four nucleotide bases, but one can have "markers"
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There are 5 : A G C T U
Adenosine, guanine, cytosine are in DNA and RNA.
DNA also has thymine.
RNA instead has uracil.
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There are five. DNA and RNA each have four but not the same four. RNA uses uracil instead of thymine. The basic five can be modified after the nucleic acid is formed, methylctosine being the most common.
There are also a bunch of other nucleotide bases that aren't normally incorporated in DNA or RNA, some of which have been found in space, and artificial ones we've engineered to fluoresce or kill cancer.
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Yum! (Score:2)
Sugars and gum!
Was that ABC gum? (Score:2)
Or was it fresh?
I'm telling you, people are so rude. They're leaving gum stuck to things even in space now!
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Re: Was that ABC gum? (Score:2)
Paging Benford and Brin... (Score:1)
We just want you to be happy . . . (Score:2)
Burn the samples. Blow up the asteroid!