6 ms·

Color me a bad reader: what does this mean? The abstract pretty much leaves me in the abstract.

by bastih 2y ago

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 ago
  I 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 ago
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
- jfengel 2y ago
  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.
  - pavel_lishin 2y ago
    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.)
  - eru 2y ago
    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.
    - harshreality 2y ago
      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. [2] https://www.sciencenews.org/article/mars-farming-harder-martian-regolith-soil https://www.sciencenews.org/article/mars-farming-harder-mart...
- asdff 2y ago
  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.
plxxyzs 2y ago
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.
- pvaldes 2y ago
  We should expect that, as the area is miraculously devoid of competitors, poisoners like fungus and predators. Those bacteria are the first colonists. Now we can wait for a colon bacteria colonizing this space turd and the jokes will write itself.
theamk 2y ago
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. https://news.ycombinator.com/item?id=42268396 https://news.ycombinator.com/item?id=42268396
alganet 2y ago
It means the sample was spoiled. We can't exactly use it to understand the possibility of extraterrestrial life or life's building blocks. But since they were very careful, it is still useful to understand other meteorites and how they could have been contaminated as well. It also serves to predebunk anyone who would want to imply that those microbes were of alien origin.

Color me a bad reader: what does this mean? The abstract pretty much leaves me in the abstract.

by bastih 2y ago

Color me a bad reader: what does this mean? The abstract pretty much leaves me in the abstract.

> 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 ago
I 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 ago

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

jfengel 2y ago
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.
- pavel_lishin 2y ago
  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.)
- eru 2y ago
  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.
  - harshreality 2y ago
    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. [2] https://www.sciencenews.org/article/mars-farming-harder-martian-regolith-soil https://www.sciencenews.org/article/mars-farming-harder-mart...
asdff 2y ago
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.

plxxyzs 2y ago

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.

pvaldes 2y ago
We should expect that, as the area is miraculously devoid of competitors, poisoners like fungus and predators. Those bacteria are the first colonists. Now we can wait for a colon bacteria colonizing this space turd and the jokes will write itself.

theamk 2y ago

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. https://news.ycombinator.com/item?id=42268396 https://news.ycombinator.com/item?id=42268396

alganet 2y ago

It means the sample was spoiled. We can't exactly use it to understand the possibility of extraterrestrial life or life's building blocks. But since they were very careful, it is still useful to understand other meteorites and how they could have been contaminated as well. It also serves to predebunk anyone who would want to imply that those microbes were of alien origin.