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The implication is that there’s liquid water right under the surface if Europa. That would be fairly exciting if confirmed. Im not sure theres a single place on

The implication is that there’s liquid water right under the surface if Europa. That would be fairly exciting if confirmed. Im not sure theres a single place on earth with water but not without life.

gambiting 4y ago
The interesting question is that since water is such a fantastic medium for earth-based life, how can we make sure that any probe sent from here to say, sample the water on Europa won't contaminate it. It's my understanding that even though all planetary landers are sanitized it's almost impossible to make sure no life survives on them. Which I guess isn't too much of an issue on the moon or Mars, but any microbes would have much better chances of surviving in the water environment of Europa.
- dtx1 4y ago
  On the other hand, accidently planting life there to make it inhabitable one day doesn't sound too bad either
  - kuprel 4y ago
    Yeah and we could still distinguish it from alien life later with genetic analysis
    - LatteLazy 4y ago
      That assumes that native life doesn't just get out competed by the introduced life...
      - belter 4y ago
        Maybe that is what happened here. The cycle completes...
      - jstanley 4y ago
        It seems more likely that the opposite would happen. Life that has evolved on Mars would probably be better suited to Mars than life that evolved on Earth.
- Cthulhu_ 4y ago
  Makes me wonder if even a probe never landing would 'shed' some biological material that eventually makes its way onto the surface. Then again, there's plenty of theories that asteroids and other impacts have caused enough of a splash to throw trace life bearing materials into space and eventually onto other planets or moons. My current theory is that we will find traces of e.g. bacteria all over our solar system, but it'll be genetically traceable back to Earth. That said, if it turns out life as we know actually started on e.g. Mars, that would be huge and probably a big accelerator for more missions there.
  - ASalazarMX 4y ago
    > That said, if it turns out life as we know actually started on e.g. Mars, that would be huge and probably a big accelerator for more missions there. Mining ice deposits would be a pretty hairy business, as any surviving microorganisms would be compatible with our biology.
- clarionbell 4y ago
  That depends on the nutrients available. Water is one necessity for terran life, but you also need some building material and a source of energy. And obviously absence of anything toxic. In short lot of things need to align. Now, even if there are conditions favorable for our bacteria, the question of competition remains. Hypothetically, the invaders can carve niche in local ecology, as they often do on Earth, or they might utterly fail, as happens even more often on Earth. If there are organisms on Europa already, and that is a big 'if', they would have several billions of years worth of head start adapting to the environment and molding it to their image. Conversely, newly introduced bacteria, already damaged by exposure to deep space and deprived of nutrients for many months or years, would see it for the first time. It isn't given that this experience would work out for them, to say at least.
- twic 4y ago
  This is the job of the space agencies' planetary protection officers: https://sma.nasa.gov/sma-disciplines/planetary-protection https://sma.nasa.gov/sma-disciplines/planetary-protection https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Exploration/Planetary_protection https://www.esa.int/Science_Exploration/Human_and_Robotic_Ex... There's a handbook and everything: https://ec.europa.eu/research/participants/documents/downloadPublic/NHY0a2o4bVRJQWhPQkpRajBuRWNXWTgxdS9RWEFXdXJBUzVVeDA1WXYzbXpBeGJ5dWZyd3N3PT0=/attachment/VFEyQTQ4M3ptUWRBd1IwZnoramRydVNQZlNYQUplalA= https://ec.europa.eu/research/participants/documents/downloa...
  - ceejayoz 4y ago
    I know it's a lot more mundane than it sounds, but what a title to have on your business cards.
- mrfusion 4y ago
  Better to take that risk and learn what’s there than to never know.
codewiz 4y ago
> Im not sure theres a single place on earth with water but not without life. I'm not sure I'm not having a hard time parsing this triple negation :-) Are you saying that all places on earth with water also have life?
- dataflow 4y ago
  Yes, it's saying (water ∧ ¬life) = false, which implies (¬water ∨ life) = true, which implies water ⇒ life.
  - Beltiras 4y ago
    I'm not quite sure that I had this original thought myself or read it somewhere but an alternate definition of life is the ability of membranes to hold water. One of the first things to happen upon decomposing is the organism can't hold water anymore. I find it an interesting criteria that for example classifies virii as non living.
belter 4y ago
Not optimistic about the possibility of life in Europe. Tenuous atmosphere so little protection from the Sun. Also radiation is maybe too strong. Europa receives around 600 rem of radiation per day. It's so much radiation it shines: "Europa Glows: Radiation Does a Bright Number on Jupiter's Moon" https://www.nasa.gov/feature/jpl/europa-glows-radiation-does-a-bright-number-on-jupiters-moon https://www.nasa.gov/feature/jpl/europa-glows-radiation-does... I say we land on Titan: "Let's Colonize Titan" https://blogs.scientificamerican.com/guest-blog/lets-colonize-titan/ https://blogs.scientificamerican.com/guest-blog/lets-coloniz...
- ClumsyPilot 4y ago
  Life on europa id always discussed under ice, which is thick enoufh to block all radiation
  - belter 4y ago
    True, but without light it's even harder. Of course we have seen life here around thermal vents but did it originate without light?
    - Sharlin 4y ago
      Light is not needed. Life on Earth got along fine without photosynthesis for hundreds of millions of years, and the hypothesis that life first appeared on Earth on the seafloor around thermal vents is quite plausible, even if we might never know for sure.
      - tokai 4y ago
        Life was also around here when the earth was a snow ball covered in ice.
        Sharlin 4y ago
        Yes, although I think it's still debated whether there actually were any "total snowball" events or whether even the most severe ones still had open ocean near the equator.
subhro 4y ago
> Im not sure theres a single place on earth with water but not without life. Really not trying to be a spoilsport here. But how about Dead Sea? ^_^
- gee_totes 4y ago
  I don't think the Dead Sea is really dead. "Biologists have known since the 1930s the lake is "not dead yet". Instead, it's full of microbes that get along quite happily in the salty soup, for it keeps out competitors that would take over in a more hospital aqueous environment. In general, the water contains 1,000 to 10,000 archaea* per ml, a much lower concentration of life than in seawater, but quite respectable, all in all, for a place where one molecule in three is not water. Occasionally, when conditions are right, the sea blooms red with life. This happened in 1980 and 1992." from: https://blogs.scientificamerican.com/artful-amoeba/fountains-of-life-found-at-the-bottom-of-the-dead-sea/ https://blogs.scientificamerican.com/artful-amoeba/fountains...

gambiting 4y ago

The interesting question is that since water is such a fantastic medium for earth-based life, how can we make sure that any probe sent from here to say, sample the water on Europa won't contaminate it. It's my understanding that even though all planetary landers are sanitized it's almost impossible to make sure no life survives on them. Which I guess isn't too much of an issue on the moon or Mars, but any microbes would have much better chances of surviving in the water environment of Europa.

dtx1 4y ago
On the other hand, accidently planting life there to make it inhabitable one day doesn't sound too bad either
- kuprel 4y ago
  Yeah and we could still distinguish it from alien life later with genetic analysis
  - LatteLazy 4y ago
    That assumes that native life doesn't just get out competed by the introduced life...
    - belter 4y ago
      Maybe that is what happened here. The cycle completes...
    - jstanley 4y ago
      It seems more likely that the opposite would happen. Life that has evolved on Mars would probably be better suited to Mars than life that evolved on Earth.
Cthulhu_ 4y ago
Makes me wonder if even a probe never landing would 'shed' some biological material that eventually makes its way onto the surface. Then again, there's plenty of theories that asteroids and other impacts have caused enough of a splash to throw trace life bearing materials into space and eventually onto other planets or moons. My current theory is that we will find traces of e.g. bacteria all over our solar system, but it'll be genetically traceable back to Earth. That said, if it turns out life as we know actually started on e.g. Mars, that would be huge and probably a big accelerator for more missions there.
- ASalazarMX 4y ago
  > That said, if it turns out life as we know actually started on e.g. Mars, that would be huge and probably a big accelerator for more missions there. Mining ice deposits would be a pretty hairy business, as any surviving microorganisms would be compatible with our biology.
clarionbell 4y ago
That depends on the nutrients available. Water is one necessity for terran life, but you also need some building material and a source of energy. And obviously absence of anything toxic. In short lot of things need to align. Now, even if there are conditions favorable for our bacteria, the question of competition remains. Hypothetically, the invaders can carve niche in local ecology, as they often do on Earth, or they might utterly fail, as happens even more often on Earth. If there are organisms on Europa already, and that is a big 'if', they would have several billions of years worth of head start adapting to the environment and molding it to their image. Conversely, newly introduced bacteria, already damaged by exposure to deep space and deprived of nutrients for many months or years, would see it for the first time. It isn't given that this experience would work out for them, to say at least.
twic 4y ago
This is the job of the space agencies' planetary protection officers: https://sma.nasa.gov/sma-disciplines/planetary-protection https://sma.nasa.gov/sma-disciplines/planetary-protection https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Exploration/Planetary_protection https://www.esa.int/Science_Exploration/Human_and_Robotic_Ex... There's a handbook and everything: https://ec.europa.eu/research/participants/documents/downloadPublic/NHY0a2o4bVRJQWhPQkpRajBuRWNXWTgxdS9RWEFXdXJBUzVVeDA1WXYzbXpBeGJ5dWZyd3N3PT0=/attachment/VFEyQTQ4M3ptUWRBd1IwZnoramRydVNQZlNYQUplalA= https://ec.europa.eu/research/participants/documents/downloa...
- ceejayoz 4y ago
  I know it's a lot more mundane than it sounds, but what a title to have on your business cards.
mrfusion 4y ago
Better to take that risk and learn what’s there than to never know.

codewiz 4y ago

> Im not sure theres a single place on earth with water but not without life. I'm not sure I'm not having a hard time parsing this triple negation :-) Are you saying that all places on earth with water also have life?

dataflow 4y ago
Yes, it's saying (water ∧ ¬life) = false, which implies (¬water ∨ life) = true, which implies water ⇒ life.
- Beltiras 4y ago
  I'm not quite sure that I had this original thought myself or read it somewhere but an alternate definition of life is the ability of membranes to hold water. One of the first things to happen upon decomposing is the organism can't hold water anymore. I find it an interesting criteria that for example classifies virii as non living.

belter 4y ago

Not optimistic about the possibility of life in Europe. Tenuous atmosphere so little protection from the Sun. Also radiation is maybe too strong. Europa receives around 600 rem of radiation per day. It's so much radiation it shines: "Europa Glows: Radiation Does a Bright Number on Jupiter's Moon" https://www.nasa.gov/feature/jpl/europa-glows-radiation-does-a-bright-number-on-jupiters-moon https://www.nasa.gov/feature/jpl/europa-glows-radiation-does... I say we land on Titan: "Let's Colonize Titan" https://blogs.scientificamerican.com/guest-blog/lets-colonize-titan/ https://blogs.scientificamerican.com/guest-blog/lets-coloniz...

ClumsyPilot 4y ago
Life on europa id always discussed under ice, which is thick enoufh to block all radiation
- belter 4y ago
  True, but without light it's even harder. Of course we have seen life here around thermal vents but did it originate without light?
  - Sharlin 4y ago
    Light is not needed. Life on Earth got along fine without photosynthesis for hundreds of millions of years, and the hypothesis that life first appeared on Earth on the seafloor around thermal vents is quite plausible, even if we might never know for sure.
    - tokai 4y ago
      Life was also around here when the earth was a snow ball covered in ice.
      - Sharlin 4y ago
        Yes, although I think it's still debated whether there actually were any "total snowball" events or whether even the most severe ones still had open ocean near the equator.

subhro 4y ago

> Im not sure theres a single place on earth with water but not without life. Really not trying to be a spoilsport here. But how about Dead Sea? ^_^

gee_totes 4y ago
I don't think the Dead Sea is really dead. "Biologists have known since the 1930s the lake is "not dead yet". Instead, it's full of microbes that get along quite happily in the salty soup, for it keeps out competitors that would take over in a more hospital aqueous environment. In general, the water contains 1,000 to 10,000 archaea* per ml, a much lower concentration of life than in seawater, but quite respectable, all in all, for a place where one molecule in three is not water. Occasionally, when conditions are right, the sea blooms red with life. This happened in 1980 and 1992." from: https://blogs.scientificamerican.com/artful-amoeba/fountains-of-life-found-at-the-bottom-of-the-dead-sea/ https://blogs.scientificamerican.com/artful-amoeba/fountains...