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NASA's Asteroid Bennu Sample Reveals Mix of Life's Ingredients

106 points by zrkrlc 2y ago

bruce511 2y ago
While it's unlikely this really moves the needle in terms of other life in the solar system (which seems like a pretty hard "no" to me as a lay person), it perhaps does have an impact on "rest if the galaxy". Of course the ingredients are "necessary but not sufficient ". However being "abundant" increases the chance of them being present when the other necessary conditions are met.
- gyomu 2y ago
  > other life in the solar system (which seems like a pretty hard "no" to me as a lay person), There’s so much we don’t know about the solar system, little bacteria crawling around deep under the crust of a moon or swirling about in a gassy giant doesn’t seem too far fetched. Wormy fishy creatures (or even more complex than that) under the ice of Europa is a bit more of a stretch, but even then I don’t think we’re aware of anything that would outright refute that possibility as of now.
  - ceejayoz 2y ago
    Yeah, ruling anything out when we’re still finding new muscles (https://thehill.com/changing-america/well-being/medical-advances/586653-researchers-discover-new-muscle-layer-in-humans/amp/ https://thehill.com/changing-america/well-being/medical-adva...) and weird structures (https://www.science.org/content/blog-post/what-s-obelisk-anyway https://www.science.org/content/blog-post/what-s-obelisk-any...) in humans - to which we have plenty of access - seems deeply premature.
    - mrguyorama 2y ago
      The traditional way to demonstrate this is how little we know about the ocean floor and the types, styles, and varieties of life therein. Every time we look we find a textbook's worth of new types of creatures, and usually break at least one minor "rule" of how life works, for example, "dark oxygen".
  - lm28469 2y ago
    And people tend to forget about time. There might have been bacterias somewhere 1b years ago or in 1b years. Space is big as fuck but when you add time in the mix it's as close to infinite as you can get.
- someothherguyy 2y ago
  At least wait for https://en.wikipedia.org/wiki/Europa_Clipper https://en.wikipedia.org/wiki/Europa_Clipper
- raverbashing 2y ago
  Yeah I'm thinking this definitely pushes the start of life in the bigger universe some billion years before the start of life on Earth. Possibly a lot of billion years. (though you still need a couple of generations of stars to get carbon, nitrogen and phosphorus)
- baq 2y ago
  Let’s wait for the Europa lander and nuclear submarine to make sure. Chances are slim but not zero.
  - itishappy 2y ago
    We have no plans for anything like that. Few proposals, but nothing concrete. Europa Clipper is what we've got for now.
    - baq 2y ago
      > We have no plans for anything like that. That's kinda my point... I'm pretty sure I won't live long enough to see it happen, but I hope we plan and launch a mission like that!
- Symmetry 2y ago
  Life arose on Earth shockingly quickly on Earth as best as we can tell from the fossil record. Especially compared to apparently much more difficult innovations like photosynthesis, mitochondria, or multi-cellularity. I wouldn't at all be surprised if bodies in the solar system with liquid water and active enough geologies to produce consumable chemicals have primitive life.
  - mapt 2y ago
    One of the inputs to this that has shifted recently is that scientists are finding it difficult to locate a core sample of solid rock, anywhere, that is completely sterile. It seems like ecology percolates through almost anything in the crust with pore spaces and a temperature under or at 100C or so. That shift from "Opportunities for life" being measured based on surface area to volume is dramatic.
- deleted 2y ago
  [deleted]
hirokio123 2y ago
The theory of physicochemist Arrhenius strongly suggests that we are the descendants of life that arrived on Earth carried by spores from space.
- adrian_b 2y ago
  By the time when Arrhenius proposed this theory he did not really have any argument supporting it. Now, there exists only one argument supporting it. The last common ancestor of all cellular living beings that exist on Earth was already a quite complex bacterium. There is no doubt that it was the product of an already very long evolution process. For instance the genetic code that is used, with very small variations, by all living beings on Earth must have succeeded a long sequence of simpler genetic codes, with an increase of each step of the complexity of the code and of the number of amino-acids that could be encoded. The oldest versions of the genetic code are likely to have encoded only between 4 and 6 amino-acids instead of 20 to 22, like today. Based on the probable bacterial fossils that are quite old, it seems like the time from the apparition of life on Earth might have been too short to explain the complexity of the last common ancestor of the present living beings. So this supports the idea that life could have appeared elsewhere, but then some bacteria and viruses have reached Earth and then they have evolved further. Even in the unlikely case when this supposition were true, this changes nothing about the appearance of life, it just pushes it to another place that must have had a pretty much identical environment with the primitive Earth, in order to make possible the apparition of life. Life cannot appear without a continuous source of energy for it. There exists only one known source of energy that can be used by the simplest possible forms of life, and this source of energy is the internal heat of a relatively big planet or of a very large satellite, like Titan or the big satellites of Jupiter. The internal planetary heat can provide the energy for sustaining life indirectly, through volcans or hydrothermal vents. When volcanic rocks are ejected from the hotter inside of a planet, they consist of chemical substances that are no longer in chemical equilibrium at the lower temperature of the planet surface. This causes chemical reactions that result in substances like free dihydrogen, which, in the presence of catalysts, make possible the continuous synthesis of the complex organic molecules required for life. As far as we know, Earth had ideal conditions for the appearance of life right here. It did not need to be colonized by bacterial spores coming for elsewhere. The only reason why there is a very small chance for Arrhenius to have been right, is that the bigger Earth has remained very hot for a longer time than smaller planets like Mars, delaying the apparition of life here. So it might have been possible for a place like Mars to have conditions suitable for the appearance of life before Earth. Life could have been appeared there and it could have been transported by one of the many meteorites that are known to have come from Mars to Earth as a consequence of big impacts. Then Mars has lost most of its atmosphere and it became very cold, so if it ever had life, that could have disappeared. For now this scenario that would match the theory of Arrhenius cannot be considered as 100% excluded, but in any case it is far-fetched and it does not change anything about the evolution of the living beings known on Earth, even if the initial part of that evolution could have taken place elsewhere, but in conditions not really different from those of the primitive Earth.
netcraft 2y ago
Given that the Ryugu sample was contaminated, how confident are we that these samples werent also contaminated? https://phys.org/news/2024-11-ryugu-asteroid-sample-rapidly-colonized.html https://phys.org/news/2024-11-ryugu-asteroid-sample-rapidly-...
- ceejayoz 2y ago
  https://www.rochester.edu/newscenter/nasa-bennu-asteroid-space-rocks-dust-curation-637932/ https://www.rochester.edu/newscenter/nasa-bennu-asteroid-spa... > Key to the curation process was the use of so-called “witness plates”—flat plates made of aluminum and sapphire—that were exposed to all the same conditions as the sample from Bennu, creating a detailed record of potential contaminants. > If a compound found in the Bennu sample wasn’t on the witness plate, scientists could confidently identify it as originating from Bennu. This is critical when dealing with organic compounds, where contamination can make it hard to distinguish what is truly extraterrestrial.
- gus_massa 2y ago
  > Many amino acids can be created in two mirror-image versions, like a pair of left and right hands. Life on Earth almost exclusively produces the left-handed variety, but the Bennu samples contain an equal mixture of both. This is a very strong indication that the amino acids in the sample where made by an inorganic process.
  - AnimalMuppet 2y ago
    Is it? Or is it a very strong indication that the amino acids in the sample were not contamination by life on Earth? That is, while life on Earth is left-handed, I don't know of any reason to assume that life elsewhere must be either left- or right-handed. I don't actually believe in panspermia. I just think that it's important to not infer more than the evidence actually gives.
    - Out_of_Characte 2y ago
      Life uses the exact same chemistry as any inorganic process exept life is far more competent than random reaction products. This is why the expected origin is inorganic as left handed and right handed are equally likely to occur in an inorganic process. So occams razor suggests that either 1) life must specifically balance their left-right handed molecules 2) Other processes that favor any handedness must not be present. or the process is inorganic which we know couldn't favor left or righthandedness in the first place.

106 points by zrkrlc 2y ago

While it's unlikely this really moves the needle in terms of other life in the solar system (which seems like a pretty hard "no" to me as a lay person), it perhaps does have an impact on "rest if the galaxy". Of course the ingredients are "necessary but not sufficient ". However being "abundant" increases the chance of them being present when the other necessary conditions are met.

gyomu 2y ago
> other life in the solar system (which seems like a pretty hard "no" to me as a lay person), There’s so much we don’t know about the solar system, little bacteria crawling around deep under the crust of a moon or swirling about in a gassy giant doesn’t seem too far fetched. Wormy fishy creatures (or even more complex than that) under the ice of Europa is a bit more of a stretch, but even then I don’t think we’re aware of anything that would outright refute that possibility as of now.
- ceejayoz 2y ago
  Yeah, ruling anything out when we’re still finding new muscles (https://thehill.com/changing-america/well-being/medical-advances/586653-researchers-discover-new-muscle-layer-in-humans/amp/ https://thehill.com/changing-america/well-being/medical-adva...) and weird structures (https://www.science.org/content/blog-post/what-s-obelisk-anyway https://www.science.org/content/blog-post/what-s-obelisk-any...) in humans - to which we have plenty of access - seems deeply premature.
  - mrguyorama 2y ago
    The traditional way to demonstrate this is how little we know about the ocean floor and the types, styles, and varieties of life therein. Every time we look we find a textbook's worth of new types of creatures, and usually break at least one minor "rule" of how life works, for example, "dark oxygen".
- lm28469 2y ago
  And people tend to forget about time. There might have been bacterias somewhere 1b years ago or in 1b years. Space is big as fuck but when you add time in the mix it's as close to infinite as you can get.
someothherguyy 2y ago
At least wait for https://en.wikipedia.org/wiki/Europa_Clipper https://en.wikipedia.org/wiki/Europa_Clipper
raverbashing 2y ago
Yeah I'm thinking this definitely pushes the start of life in the bigger universe some billion years before the start of life on Earth. Possibly a lot of billion years. (though you still need a couple of generations of stars to get carbon, nitrogen and phosphorus)
baq 2y ago
Let’s wait for the Europa lander and nuclear submarine to make sure. Chances are slim but not zero.
- itishappy 2y ago
  We have no plans for anything like that. Few proposals, but nothing concrete. Europa Clipper is what we've got for now.
  - baq 2y ago
    > We have no plans for anything like that. That's kinda my point... I'm pretty sure I won't live long enough to see it happen, but I hope we plan and launch a mission like that!
Symmetry 2y ago
Life arose on Earth shockingly quickly on Earth as best as we can tell from the fossil record. Especially compared to apparently much more difficult innovations like photosynthesis, mitochondria, or multi-cellularity. I wouldn't at all be surprised if bodies in the solar system with liquid water and active enough geologies to produce consumable chemicals have primitive life.
- mapt 2y ago
  One of the inputs to this that has shifted recently is that scientists are finding it difficult to locate a core sample of solid rock, anywhere, that is completely sterile. It seems like ecology percolates through almost anything in the crust with pore spaces and a temperature under or at 100C or so. That shift from "Opportunities for life" being measured based on surface area to volume is dramatic.
deleted 2y ago
[deleted]

hirokio123 2y ago

The theory of physicochemist Arrhenius strongly suggests that we are the descendants of life that arrived on Earth carried by spores from space.

adrian_b 2y ago
By the time when Arrhenius proposed this theory he did not really have any argument supporting it. Now, there exists only one argument supporting it. The last common ancestor of all cellular living beings that exist on Earth was already a quite complex bacterium. There is no doubt that it was the product of an already very long evolution process. For instance the genetic code that is used, with very small variations, by all living beings on Earth must have succeeded a long sequence of simpler genetic codes, with an increase of each step of the complexity of the code and of the number of amino-acids that could be encoded. The oldest versions of the genetic code are likely to have encoded only between 4 and 6 amino-acids instead of 20 to 22, like today. Based on the probable bacterial fossils that are quite old, it seems like the time from the apparition of life on Earth might have been too short to explain the complexity of the last common ancestor of the present living beings. So this supports the idea that life could have appeared elsewhere, but then some bacteria and viruses have reached Earth and then they have evolved further. Even in the unlikely case when this supposition were true, this changes nothing about the appearance of life, it just pushes it to another place that must have had a pretty much identical environment with the primitive Earth, in order to make possible the apparition of life. Life cannot appear without a continuous source of energy for it. There exists only one known source of energy that can be used by the simplest possible forms of life, and this source of energy is the internal heat of a relatively big planet or of a very large satellite, like Titan or the big satellites of Jupiter. The internal planetary heat can provide the energy for sustaining life indirectly, through volcans or hydrothermal vents. When volcanic rocks are ejected from the hotter inside of a planet, they consist of chemical substances that are no longer in chemical equilibrium at the lower temperature of the planet surface. This causes chemical reactions that result in substances like free dihydrogen, which, in the presence of catalysts, make possible the continuous synthesis of the complex organic molecules required for life. As far as we know, Earth had ideal conditions for the appearance of life right here. It did not need to be colonized by bacterial spores coming for elsewhere. The only reason why there is a very small chance for Arrhenius to have been right, is that the bigger Earth has remained very hot for a longer time than smaller planets like Mars, delaying the apparition of life here. So it might have been possible for a place like Mars to have conditions suitable for the appearance of life before Earth. Life could have been appeared there and it could have been transported by one of the many meteorites that are known to have come from Mars to Earth as a consequence of big impacts. Then Mars has lost most of its atmosphere and it became very cold, so if it ever had life, that could have disappeared. For now this scenario that would match the theory of Arrhenius cannot be considered as 100% excluded, but in any case it is far-fetched and it does not change anything about the evolution of the living beings known on Earth, even if the initial part of that evolution could have taken place elsewhere, but in conditions not really different from those of the primitive Earth.

netcraft 2y ago

Given that the Ryugu sample was contaminated, how confident are we that these samples werent also contaminated? https://phys.org/news/2024-11-ryugu-asteroid-sample-rapidly-colonized.html https://phys.org/news/2024-11-ryugu-asteroid-sample-rapidly-...

ceejayoz 2y ago
https://www.rochester.edu/newscenter/nasa-bennu-asteroid-space-rocks-dust-curation-637932/ https://www.rochester.edu/newscenter/nasa-bennu-asteroid-spa... > Key to the curation process was the use of so-called “witness plates”—flat plates made of aluminum and sapphire—that were exposed to all the same conditions as the sample from Bennu, creating a detailed record of potential contaminants. > If a compound found in the Bennu sample wasn’t on the witness plate, scientists could confidently identify it as originating from Bennu. This is critical when dealing with organic compounds, where contamination can make it hard to distinguish what is truly extraterrestrial.
gus_massa 2y ago
> Many amino acids can be created in two mirror-image versions, like a pair of left and right hands. Life on Earth almost exclusively produces the left-handed variety, but the Bennu samples contain an equal mixture of both. This is a very strong indication that the amino acids in the sample where made by an inorganic process.
- AnimalMuppet 2y ago
  Is it? Or is it a very strong indication that the amino acids in the sample were not contamination by life on Earth? That is, while life on Earth is left-handed, I don't know of any reason to assume that life elsewhere must be either left- or right-handed. I don't actually believe in panspermia. I just think that it's important to not infer more than the evidence actually gives.
  - Out_of_Characte 2y ago
    Life uses the exact same chemistry as any inorganic process exept life is far more competent than random reaction products. This is why the expected origin is inorganic as left handed and right handed are equally likely to occur in an inorganic process. So occams razor suggests that either 1) life must specifically balance their left-right handed molecules 2) Other processes that favor any handedness must not be present. or the process is inorganic which we know couldn't favor left or righthandedness in the first place.