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Rapid colonization of a space-returned Ryugu sample by terrestrial microorganism
- AYBABTME 2y agoConsequence: we'll find life wherever we go, and we'll never know if it was always there or if we brought it there?
- bglazer 2y agoFor the second part, we’d be able to do biochemical assays like mass spectrometry and discover immediately that the “alien” life was made of the same proteins as Earth life. Gene sequencing would then confirm a match to a known microbe, or at least to a family of them. Now, we could argue that panspermia would predict that alien life in our solar system might be similar to earth’s species, but we would expect to see some radical differences, even at a cursory first look, given the total isolation of the two life systems for (presumably) billions of years. All that to say that it would probably be quite easy to discern whether a microbe is definitely earth life.
- kombookcha 2y agoI suppose the much more bothersome scenario is finding a microbe that is ambiguously novel, and doesn't neatly fit any particular family of Earth microbes, but also isn't radically different enough to be confidently classified alien. Like did we accidentally discover an eccentric and rare Earth microorganism that thrives in this unusual environment, or is it an honest to god extraterrestrial and life in both spheres just happens to converge along certain lines by evolutionary convenience or chemical necesssity? How would we tell?
- stouset 2y agoAlien samples won’t have carbon-14, which is created in the atmosphere.
- asdff 2y agoYou’d sequence this organism. If it came from earth you could tell. People would have either sequenced it already or a distant relative species where you could compare sequence divergence and when they shared a last common ancestor. Convergent evolution might lead to similar phenotypes but the actual sequence of genes involved is only going to be similar if those genes shared an evolutionary history.
- bglazer 2y agoChemical space is very very large. Like we can say for certain that only a very tiny percentage of all possible synthesizable organic molecules have ever existed in our universe. The combinatoric explosion is just so enormous that I think its incredibly unlikely that the only configuration of molecules that supports life is our own here on Earth. In fact, I think we know this given that there are artificial amino acids that can be incorporated into our existing protein biochemistry without a problem. Thats a small example but it points to a much larger space of chemical compositions that can support life. So an entirely separate evolutionary process would almost certainly land in a very different chemistry for things like information storage and molecular machines like protein. Also our biochemistry is compositional, it takes small building blocks and remixes and combines them to build larger structures. I suspect that this is also a necessary feature of life in general. It’s very hard, basically impossible, for natural evolution to build huge structures like proteins just by pure uniform random selection. Instead it takes small pieces randomly, then puts them together to get complex life. Point being, its a very very path dependent process. Any small difference in the early building blocks gets exponentially magnified when evolution uses those blocks to build life. So that leads to easily detectable, drastic differences in biochemical structure. This is evident on earth in that our biochemistry has a feature called left handed chirality that seems to be a purely random accident of the very earliest steps of life. That then was transmitted to every living being on earth. There’s probably a fifty-fifty chance that extraterrestrial biology is right handed instead. Every step in evolution also probably has random accidents just like that. Our particular biochemistry is the result of a trillion coin flips. There are probably many other biochemistries that work just fine, but look way different
- JumpCrisscross 2y ago> How would we tell? You'd send a second mission to do analysis in situ.
- ngneer 2y agoI suppose we need a one-way valve, such that information about the sample can flow to us while nothing can affect the sample. Conceptually like a Heimlich valve. Or, as a wild alternative, we could amplify the signal in some way, perhaps using sterile equipment in space, such that any Earth life would drown out in alien life and contamination would no longer pose as big an issue.
- vasco 2y agoDepends, if you don't take anything big with you and see a dog walking around you can tell the difference.
- asdff 2y agoNo you can sequence these organisms and see where they came from. If you brought them from earth vs if they were not from earth would be apparent in genetic analysis.
- aeternum 2y agoNo, yet another conclusion where the headline that runs is one of the least probable explanations. More likely: They opened it in a museum lab with a mediocre clean room that had some stuff floating around in it and ended up culturing organisms that didn't even make the trip to space.
- bastih 2y agoColor me a bad reader: what does this mean? The abstract pretty much leaves me in the abstract.
- jcoc611 2y ago> The presence of terrestrial microorganism within a sample of Ryugu underlines that microorganisms are the world's greatest colonizers and adept at circumventing contamination controls. The presence of microorganisms within space-returned samples, even those subject to stringent contamination controls is, therefore, not necessarily evidence of an extraterrestrial origin. Basically that preventing terrestrial contamination of extraterrestrial samples is super tough, and in the specific case of Ryugu the study concludes that contamination did occur.
- hn_throwaway_99 2y agoI recall a study from a few years ago that showed that Acinetobacter bacteria can eat the detergents that NASA used to clean spacecraft to prevent contamination: https://www.theatlantic.com/science/archive/2018/06/bacteria-can-eat-the-cleaning-products-nasa-uses-to-sterilize-its-spaceships/562016/ https://www.theatlantic.com/science/archive/2018/06/bacteria...
- swagasaurus-rex 2y agoThe samples mined from the Ryugu asteroid were contaminated by earth microorganisms some time between sampling and analysis. That makes it hard to tell the difference between potentially alien microorganisms and just regular earth microorganisms
- jfengel 2y agoWhich is why I'd just as soon we waited a few extra decades before landing people on Mars. We're chock full of bacteria and they will surely get out. Unlike robots we can't be sterilized. Once we can be certain that there is no native life, go nuts. Until then it's an irreplaceable bit of data.
- downrightmike 2y agoOkay, refine procedures and try again
- londons_explore 2y ago> opened in nitrogen in a class 10,000 clean room Since these samples were collected in a vacuum, doesn't it make sense to keep them in a vacuum, at least for science that requires the smallest possible amount of contamination?
- dredmorbius 2y agoNitrogen gas is for most purposes chemically and organically inert, particularly in the absence of oxygen. It's also abundant, cheap, and non-toxic, so long as the surrounding environment has sufficient oxygen that leaks don't put personnel at risk. Glovebox construction and use is also much easier than with vacuum. A positive-pressure nitrogen environment will also limit infiltration of oxygen or other contaminants, something which cannot be said of vacuum chambers. Past experiences (see Nasa SP-88 below) show that vacuum handling provides few if any benefits and numerous risks and complexities. Nitrogen-flooded environments can be made arbitrarily large, again a characteristic that's not true of vacuum chambers. A StackExchange question addresses this topic in more depth: <https://space.stackexchange.com/questions/29727/why-does-nasa-use-nitrogen-storage-for-lunar-regolith https://space.stackexchange.com/questions/29727/why-does-nas...> That sources a 1965 Nasa document: "NASA 1965 Summer Conference on Lunar Exploration and Science" <https://www.lpi.usra.edu/lunar/documents/65_lunar_conf.pdf https://www.lpi.usra.edu/lunar/documents/65_lunar_conf.pdf> [PDF] (NASA SP-88). See p. 255.
- madaxe_again 2y agoAs per the article, however, a nitrogen atmosphere does not preclude growth of Bacillus, many species of which can tolerate a pure nitrogen atmosphere quite readily. That said, bacillus can survive hard vacuum too through sporulation, so short of analysing these samples in-situ, it’s going to be really hard to prove an ET origin for any microorganisms.
- dredmorbius 2y agoWhere specifically are you getting that information? From TFA: The nitrogen atmosphere, in which the sample was stored during this time, can be a bactericide for some, but not all, Bacillus species owing to the reduced water activity associated with the dry atmosphere (Munsch-Alatossava & Alatossava, 2014). The bactericidal effects of such atmospheres are not restricted to Bacillus, and thus provides no diagnostic information. That is: nitrogen should generally kill bacteria, but may not in the case of some Bacillus species. That's quite some distance from saying the bacteria would thrive in that environment, and I'd presume other factors (light, food supply, some means for oxidation) would be necessary, most of which could be reasonably constrained within a sample-examination environment. Origin determination might be made through C14 or other dating --- any extant in situ bioactive materials would presumably be comprised of primordial carbon with effectively no C14 signature, as opposed to any recently-deposited or growing organisms. One challenge seems to be that there was very little Bacillus present, 11 to 147 individuals, which seems to have made DNA analysis impractical and would likely challenge isotopic analysis as well. NB: Not my area of expertise, just close reading, general understanding, and some research-fu.
- metalman 2y agooccurs to me that sample return missions should ,not end up ON, earth, but in orbit where they could be retrieved and studied initialy, befor bieng packaged for earth landing, therby vastly limiting any possible cross contamination, and having a pristine storage environment for control samples
- porphyra 2y agoYeah but spacecraft themselves being contaminated is a real possibility. NASA found that some bacteria can metabolize isopropyl alcohol [1] [1] https://www.theatlantic.com/science/archive/2018/06/bacteria-can-eat-the-cleaning-products-nasa-uses-to-sterilize-its-spaceships/562016/ https://www.theatlantic.com/science/archive/2018/06/bacteria...
- tomrod 2y agoI'd prefer we seed life where we go, but I know that's against some others philosophy
- api 2y agoI am not opposed to it in most cases for any moral reason, but if we did accidentally contaminate an example of even incredibly simple ET life it would be an enormous scientific loss. What one second example of life could teach us would be massive. Contamination would mean we could never be sure we were studying the authentic thing.
- mock-possum 2y agoYeah if there’s no life there already, then we should probably go ahead and put it there and see what happens. We’d have to be real sure that there’s no life there already though.
- gambiting 2y agoThat's kinda impossible though, given the variety of environments we find life in on Earth - there are microbes living miles under the surface, on massively radioactive spent nuclear fuel, inside thermal vents that reach hundreds degrees celcius....in fact I bet there isn't any environment on Earth that doesn't have some form of life in it, other than artificially created by us. There is an argument that Mars probably already has life on it, as many of the probes we've sent almost certainly brought something with them despite our efforts to sterilize them.
- muny 2y agoI'm not super familiar, but I think a "Class 10,000" clean room is actually quite on the "dirty" end of the clean room spectrum. Perhaps they figured this had a low likelihood of being the source of domestic microbes?
- madaxe_again 2y agoCorrect. As per the paper the population of organisms suggests contamination occurred during sample preparation at the Natural History Museum.
- nis0s 2y agoIt seems then sample analysis should happen in place instead of bringing samples back to study. I think this motivates the need for better ISS equipment, or off-site research labs, like on the moon.
- eru 2y agoThe ISS is crawling with bacteria, too. Anything that humans touch, does. > [...] or off-site research labs, like on the moon. Why stick your lab in a gravity well? And why involve humans (as anything closer than remote operators of robotics)?
- pvaldes 2y agoHum, I didn't though about it. Are you saying that there are life in Mars yet, in each place that the Rover visit?
- asdff 2y agoThere is a reason they send rovers in places they expect to find ancient life and not present day life.
- pantalaimon 2y ago> The ISS is crawling with bacteria I have read that the smell must be quite peculiar, it's not like you can clean that thing.
- schiffern 2y agoBy that standard, any room you've even been in is "crawling with bacteria." The ISS is cleaned constantly, with a deeper cleaning once per week. I think any odors would be more related to using dry toilets, stretching clothing in the absence of laundry facilities, and hosting a gym (2 hours exercise per day per crewmember) with no shower. No Rinse Body Bath only goes so far. https://www.youtube.com/watch?v=JUUvlnnVMSQ https://www.youtube.com/watch?v=JUUvlnnVMSQ
- ngneer 2y agoThat's really too bad. I liked the notion that RNA found on Ryugu was brought back by Hayabusa. It feels a smidge lonelier down here on planet Earth. I imagine contamination prevention protocols will be revised.
- permo-w 2y agothis paper would do well to specifically define the term "space-returned" or use clearer terminology
- verzali 2y agoIt is literally a sample that was collected in space and returned to Earth on Hyabusa 2. > Sample A0180 is a 1 × 0.8 mm regolith particle collected by the JAXA Hyabusa 2 mission to asteroid 162173 Ryugu. Samples were collected from Ryugu during close passes of the spacecraft by capturing surface particles during two touchdown events, with the second touchdown occurring after the use of kinetic impactors to reveal subsurface materials. Sample A0180 was recovered in the first collection attempt. The particles were transported to Earth in a hermetically sealed chamber that was opened in nitrogen in a class 10,000 clean room at JAXA (Yada et al., 2022). Individual particles were picked with sterilized tools and placed in airtight containers under nitrogen for distribution to participating science teams. Prior to study the Ryugu samples had no exposure to the terrestrial environment and the JAXA contamination control protocols were of the highest standard (Yada et al., 2022).
- permo-w 2y agospace-retrieved is a better translation
- deadbabe 2y agoDoes this mean maybe we should just load up micro organisms onto probes and fire them off onto passing asteroids in hopes someday they will hit some planet somewhere and spawn new life after millions of years?
- asdff 2y agoA far more realistic prospect of backing up life on earth than using humans for sure
- BuyMyBitcoins 2y agoOne thing to consider is that even though bacteria can colonize some sterile object, they don’t seem to be able to create their own self sustaining biome. As far as we know there are no species that can truly exist independently without any resources generated from some other species. Which makes sense because full autonomy would be more costly than simply relying on organic products made by some other species in the biosphere. For instance, all Vitamin B is produced by bacteria and more complex organisms depend on it as a nutrient rather than producing it on their own.
- xeonmc 2y agoFor some reason I thought the title was in reference to the folklore legend of Urashima Taro where upon his return from Ryugu he unsealed the forbidden treasure box resulting in rapid aging of him into an old man, and that the article is discussing the role of microorganism contamination in such a phenomenon.