I'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?
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?
Nitrogen 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:
As 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.
Where 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.
For 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.
I 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?
Chemical 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
You’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.
I 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.
No 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.
No, 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.
It 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.
By 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.
That'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.
For 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.
occurs 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
I 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.
That'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.
Does 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?
One 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.
It 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).
> 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.
Basically microorganisms were able to grow in a sterile asteroid sample faster than previously anticipated. So just because there are signs of life in a recently fallen meteorite is less likely to mean there are space bacteria on it.
they got asteriod samples, and turns out that Earth bacteria grow great on them. It's a problem because from now on, if a evidence of life is discovered on sapce samples there is always a suspicion it could be contamination.
The 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
You can still tell the difference through dna evidence. In this case it would be like a ship returning with an alien book, a worker left an earth based book, you have no clue what book is which but one book shares 99% textual similarity with the king james bible. That one probably originated on earth.
Which 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.
Even robots cannot be sterilized; we've likely already infected Mars with some form of life. (Although, it's not likely that it's gonna spread far - it's a wildly hostile world.)
Agreed. And Mars isn't even a good target for colonisation. Venus and even Mercury are better, but constructing space habitats is even better.
On Venus, the surface is crazy hostile, but the atmosphere is so dense big balloons filled with a nitrogen / oxygen mixture, aka breathable air would float rather nicely, and at a height with pretty liveable temperatures.
Mercury's surface has extreme temperature variations between night and day. But if you dig underground---which you would want to do anyway for meteor protection---you'll find that the variations average out, because large amounts of rock are a good heat buffer. Models suggest that near the poles there are underground regions with nice and liveable average temperatures.
Solar energy is obviously much stronger at Venus's distance from the sun than for Mars.
On Mercury, thanks to the consistent temperature variations, you could probably set up your standard issue steam turbine power plant fairly easily, just your sources of heat and cold would be a bit more interesting than on earth.
What's the point of all that effort if those habs are going to be one-way trips for the people going there? What are they going to accomplish in their floating or underground habitats? They're not getting back to anywhere useful from either place. They're not going to survive without frequent Earth resupply[1]. Whether habs could exist is an interesting thought experiment, but that's all it is for the foreseeable future.
Even a sizable Mars colony probably won't survive without frequent Earth assistance. The Mark Watney fantasy of growing food in Martian dirt with a little added fertilizer: mostly debunked[2]. The most sustainable case—for the foreseeable future—is probably a Biosphere2-like environment, where everyone hopes there's no accident, sabotage, or environment-caused damage. How many Starship missions would it take to get enough materials to Mars to build one Biosphere2 to support 8 people?
I agree with you that meaningful colonization of Mars is not serious. I just think the prospects on the inner inner planets are even more absurd than on Mars. In a floating Venusian hab, you could generate breathable air and not much else. Underground on Mercury, getting breathable air might be a problem, but you can import—at great cost, that delta-v is brutal—anything you can fit on a suitable rocket.
There's no point to any of this except as research stations or jump-off ports, and for that Mars is the obvious choice: we can make hydrocarbon fuel there, and the surface isn't equipment-melting. But where would we be jumping off to? We have nothing planned, and no particular reason, to send humans to Europa or anywhere else.
[1] How do you resupply a floating habitat on Venus? Even if you could, the constraints and resource limitations of a floating hab would be even more severe than for an underground, resource-poor Mercury hab.
I've been saying this for ages - if you want to see if humans can survive in a completely sealed underground habitat(and it would have to be underground on Mars), just try building one at the bottom of the ocean.
And if you want a permanently occupied base in space....put one on the moon first?
There are zillions of Mars-like planemos in the galaxy - hell, there are 4 pretty similar ones just in our solar system. But Mars is the only one close enough to colonise. And if we don't colonise Mars, we'll probably never get far enough to study any of the others.
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