12 ms·

If life is there, completely disconnected from earth life, it would be dramatic. That would mean that our solar system, has life on at least two, out of nine pl

by nzonbi 9y ago

If life is there, completely disconnected from earth life, it would be dramatic. That would mean that our solar system, has life on at least two, out of nine planets. That would seem to indicate that life is a fairly common things on planets. It would allow to adjust the drake equation, to easily predict millions of planets with life. And that would mean a high probability of many advanced, intelligent civilizations on the universe.

disantlor 9y ago
how would determine that it's completely disconnected? not asking snarkily. seems like you could push the goalposts back to say that whatever allows for life on earth is true of earth + our neighborhood/solar system, but not necessarily elsewhere, sort of like how the definition of AI keeps expanding.
marktangotango 9y ago
Well, deep sea, thermal vent life is predominantly blind on earth at least. One may postulate this form of life is much less likely to form technological civilizations thus moderating such. Thoughts?
- maxxxxx 9y ago
  They may end up like the creatures in the "The Abyss" and be really good at manipulating water. Who knows?
- technotony 9y ago
  These are separate variables in the equation. The drake equation multiplies a bunch of probabilities together, one of which is "probability of planet having life" and another is "probability of life becoming technologically sophisticated". A the moment we don't really understand how life starts, so it could be really really unlikely or it could be pretty common. finding independent life events in our solar system means it's pretty common (otherwise it could be 0.00001%). Here's the full equation: https://en.wikipedia.org/wiki/Drake_equation https://en.wikipedia.org/wiki/Drake_equation
- civilian 9y ago
  So-- there are caveats. A lot of deep sea life are able to see, and it's because deep sea life also generates their own light. It's a way to communicate to mates, and a way to notice prey, and a way to bait smaller predators. I also think that echolocation has potential to be equal or better to eyesight! Bats and dolphins do great with it, and I think that it's easy to think of echolocation as being a _visual_ stimuli, even though it's not lightwave-based. I think the biggest hurdle for an underwater sentient species trying to become more advanced is the difficulties with tool-building. Simple stone tools could be made, but it becomes a lot harder to smelt iron and start doing metal-working.
  - outworlder 9y ago
    On the other hand, imagine the neat tricks they could come up with using magnesium alone. Would they have to be underwater, though? They could use the sea surface, provided the atmosphere is not toxic to them.
    - 36bydesign 9y ago
      Isn't the surface frozen?
    - civilian 9y ago
      Yeah the sea surface is a glacier. There might be air pockets though? But it would also be near-freezing there, whereas the core would be much warmer, and would also have more pressure.
  - LrnByTeach 9y ago
    I was thinking very same issue for some time. Underwater species will have limitation to advance their Intelligence due to not having access to LAND to make all kind of TOOLS which led to Human Spices advancement . It seems we have a kind of proof at this time planet Earth. 'Long-finned pilot whale' have '37 Billion' Cerebral cortex Neurons , where as Human Spices have 21 Billion . I think due to their Water environment WHALE did not become the dominant spices on EARTH but Humans became . https://en.wikipedia.org/wiki/List_of_animals_by_number_of_neurons https://en.wikipedia.org/wiki/List_of_animals_by_number_of_n...
- beamatronic 9y ago
  Consider the way such life looks to us. It's stuck down there, hampered by its environment. We might look that way to an advanced civilization. "Check out those humans, they're intelligent but they're stuck way down there on the crust of that planet, under all that air, stuck in their gravity well"
  - marktangotango 9y ago
    That's very true, if earths Gravity was just a bit stronger chemical rockets couldn't even make it to orbit. Like right now we can only get 5 to 10 percent of vehicle mass to orbit, imagine if that where 1 or .001 percent. That would make space exploration incredibly expensive. It's already prohibitive at our level of gravity.
charles-salvia 9y ago
Based on the developments in exo-planet research along with discoveries like this over the past couple of years, I would conjecture that life is ridiculously common. But by life, I mean microbial life. I would imagine that multi-cellular life is much rarer, and life capable of reaching human-level intelligence and beyond is probably absurdly rare, on the level of something like one species per galaxy. It's all worthless conjecture, of course, but the point is I wouldn't be surprised if microbial life is very, very common.
- Retric 9y ago
  On earth the jump from single celled life to multi celled life was very rapid relative to how long planets can probably support life on average. The first evidence of multicellularity is from cyanobacteria-like organisms that lived 3–3.5 billion years ago.[5] https://en.m.wikipedia.org/wiki/Multicellular_organism https://en.m.wikipedia.org/wiki/Multicellular_organism Now this is a Biofilms ala mats of multi celled organisms so it's hard to draw a clear line based on the fossils. Other contenders are much younger, but even if you use sexual reproduction as the benchmark that's still within the first 3 billion years and earth likely has another 1.75 billion to 3.25 billion years before it gets to hot.
- nostrademons 9y ago
  I'm kinda curious if there's any evidence that would support or rule out intelligent life having existed on earth before. I mean, if humanity goes extinct and it's another 65 million years before another intelligent species evolves, what evidence would they have of our existence? All our buildings would've long since crumbled into dust or been crushed by plate tectonics. Metal will corrode and rust away after a few thousand years. Our largest stone monuments will be gone after 10,000 or so. You'll find occasional fossilized skeletons, but all that would tell future species is that a bipedal mammal with a large brain once existed. Even plastics, the bane of environmentalists, degrade over a couple thousand years. Probably the only thing we'd see would be a huge mass extinction and an unusually rapid change in the earth's climate. Which we've seen several times in the geologic record already.
  - 9y ago
moomin 9y ago
It would be, but let's not get ahead of ourselves: all they've done is found evidence that it would be habitable by extremophile organisms. There's no evidence there actually are any.
moomin 9y ago
It would be, but let's not get ahead of ourselves: all they've done is found evidence that it would be habitable by extremophile organisms. There's no evidence there actually are any.
ufo 9y ago
Technically, there are only 8 planets now :)
- rspeer 9y ago
  I would say nearly everyone in astronomy and education is in agreement right now that there are at least 9 planets. The only question is which ones they are. (Mike Brown, the "Pluto killer", is searching for the distant gravitational influence that he believes to be a legit ninth planet.)
tmalsburg2 9y ago
What's the posterior distribution over numbers of life forms in the universe under some conservative prior and after finding that this moon has life, too? (Plus assuming that these events are independent, which they are probably not.)
adekok 9y ago
> If life is there, completely disconnected from earth life, IIRC (I can't find the reference now), the "dinosaur killer" asteroid would put rocks from Earth into space. With sufficient velocity that they could reach nearby solar systems within 100M years. So from a strictly physical point of view, I would argue that the odds of Earth "infecting" Europa with life in the past 3 billion years are pretty much 100%.
- scoofy 9y ago
  >So from a strictly physical point of view, I would argue that the odds of Earth "infecting" Europa with life in the past 3 billion years are pretty much 100%. This is exactly why europa is so important. It's that the gravity well of jupiter is so great, that infection of europa is extremely unlikely, rather than being extremely likely. Europa would be a vastly better case for arguing separate origins of life than any other place in our solar system. Since earth has only existed for a short time in the grand scheme of things, and supposing that life indeed sprung here on its own, the odds of a random rock from a random few impacts landed on europa, rather than jupiter, in such a way to get to survive is absurdly small.
- hackuser 9y ago
  Europa is an extremely tiny target to hit randomly from Earth, probably made smaller by the fact that, in order to hit Europa, the object has to pass near Jupiter without getting pulled into it. On the other hand, there are billions of years of random attempts, as you said.
  - adrianN 9y ago
    But there is a big lump of mass near Europa that tends to attract projectiles.
    - kerbalspacepro 9y ago
      You mean the wormhole with a blackhole on the other side?
    - 9y ago
IndianAstronaut 9y ago
If life was not there, I would wager that life is exceedingly rare in our universe.
otempomores 9y ago
A dark forrest teaming with live
otempomores 9y ago
A dark forrest teaming with live
jordache 9y ago
would you be really surprised though? I've already come to the conclusion that there is/was some sort of life within our solar system. Intelligent life is much more rare. If there is some evidence of that in our solar system, I would be floored
ziikutv 9y ago
Mermaids?
Symmetry 9y ago
It wouldn't really be surprising. Prokaryotic life appeared on Earth very quickly after the Earth cooled down. But it took a very long time after that for Eukaryotic cells to develop. Just going from Earth history I'd expect lots of planets with bacterial mats but very few with complex or multi-cellular life.
- reubenswartz 9y ago
  It seems like it happened "very quickly" compared to the evolution of eukaryotic cells and multicellular life, but it still took hundreds of millions of years, and it probably happened once or a handful of times, not all over the planet. I share your expectations, but it's hard to know if it's common even for bacterial-level life to arise.

by nzonbi 9y ago

disantlor 9y ago

how would determine that it's completely disconnected? not asking snarkily. seems like you could push the goalposts back to say that whatever allows for life on earth is true of earth + our neighborhood/solar system, but not necessarily elsewhere, sort of like how the definition of AI keeps expanding.

marktangotango 9y ago

Well, deep sea, thermal vent life is predominantly blind on earth at least. One may postulate this form of life is much less likely to form technological civilizations thus moderating such. Thoughts?

maxxxxx 9y ago
They may end up like the creatures in the "The Abyss" and be really good at manipulating water. Who knows?
technotony 9y ago
These are separate variables in the equation. The drake equation multiplies a bunch of probabilities together, one of which is "probability of planet having life" and another is "probability of life becoming technologically sophisticated". A the moment we don't really understand how life starts, so it could be really really unlikely or it could be pretty common. finding independent life events in our solar system means it's pretty common (otherwise it could be 0.00001%). Here's the full equation: https://en.wikipedia.org/wiki/Drake_equation https://en.wikipedia.org/wiki/Drake_equation
civilian 9y ago
So-- there are caveats. A lot of deep sea life are able to see, and it's because deep sea life also generates their own light. It's a way to communicate to mates, and a way to notice prey, and a way to bait smaller predators. I also think that echolocation has potential to be equal or better to eyesight! Bats and dolphins do great with it, and I think that it's easy to think of echolocation as being a _visual_ stimuli, even though it's not lightwave-based. I think the biggest hurdle for an underwater sentient species trying to become more advanced is the difficulties with tool-building. Simple stone tools could be made, but it becomes a lot harder to smelt iron and start doing metal-working.
- outworlder 9y ago
  On the other hand, imagine the neat tricks they could come up with using magnesium alone. Would they have to be underwater, though? They could use the sea surface, provided the atmosphere is not toxic to them.
  - 36bydesign 9y ago
    Isn't the surface frozen?
  - civilian 9y ago
    Yeah the sea surface is a glacier. There might be air pockets though? But it would also be near-freezing there, whereas the core would be much warmer, and would also have more pressure.
- LrnByTeach 9y ago
  I was thinking very same issue for some time. Underwater species will have limitation to advance their Intelligence due to not having access to LAND to make all kind of TOOLS which led to Human Spices advancement . It seems we have a kind of proof at this time planet Earth. 'Long-finned pilot whale' have '37 Billion' Cerebral cortex Neurons , where as Human Spices have 21 Billion . I think due to their Water environment WHALE did not become the dominant spices on EARTH but Humans became . https://en.wikipedia.org/wiki/List_of_animals_by_number_of_neurons https://en.wikipedia.org/wiki/List_of_animals_by_number_of_n...
beamatronic 9y ago
Consider the way such life looks to us. It's stuck down there, hampered by its environment. We might look that way to an advanced civilization. "Check out those humans, they're intelligent but they're stuck way down there on the crust of that planet, under all that air, stuck in their gravity well"
- marktangotango 9y ago
  That's very true, if earths Gravity was just a bit stronger chemical rockets couldn't even make it to orbit. Like right now we can only get 5 to 10 percent of vehicle mass to orbit, imagine if that where 1 or .001 percent. That would make space exploration incredibly expensive. It's already prohibitive at our level of gravity.

charles-salvia 9y ago

Based on the developments in exo-planet research along with discoveries like this over the past couple of years, I would conjecture that life is ridiculously common. But by life, I mean microbial life. I would imagine that multi-cellular life is much rarer, and life capable of reaching human-level intelligence and beyond is probably absurdly rare, on the level of something like one species per galaxy. It's all worthless conjecture, of course, but the point is I wouldn't be surprised if microbial life is very, very common.

Retric 9y ago
On earth the jump from single celled life to multi celled life was very rapid relative to how long planets can probably support life on average. The first evidence of multicellularity is from cyanobacteria-like organisms that lived 3–3.5 billion years ago.[5] https://en.m.wikipedia.org/wiki/Multicellular_organism https://en.m.wikipedia.org/wiki/Multicellular_organism Now this is a Biofilms ala mats of multi celled organisms so it's hard to draw a clear line based on the fossils. Other contenders are much younger, but even if you use sexual reproduction as the benchmark that's still within the first 3 billion years and earth likely has another 1.75 billion to 3.25 billion years before it gets to hot.
nostrademons 9y ago
I'm kinda curious if there's any evidence that would support or rule out intelligent life having existed on earth before. I mean, if humanity goes extinct and it's another 65 million years before another intelligent species evolves, what evidence would they have of our existence? All our buildings would've long since crumbled into dust or been crushed by plate tectonics. Metal will corrode and rust away after a few thousand years. Our largest stone monuments will be gone after 10,000 or so. You'll find occasional fossilized skeletons, but all that would tell future species is that a bipedal mammal with a large brain once existed. Even plastics, the bane of environmentalists, degrade over a couple thousand years. Probably the only thing we'd see would be a huge mass extinction and an unusually rapid change in the earth's climate. Which we've seen several times in the geologic record already.
- 9y ago

moomin 9y ago

It would be, but let's not get ahead of ourselves: all they've done is found evidence that it would be habitable by extremophile organisms. There's no evidence there actually are any.

moomin 9y ago

It would be, but let's not get ahead of ourselves: all they've done is found evidence that it would be habitable by extremophile organisms. There's no evidence there actually are any.

ufo 9y ago

Technically, there are only 8 planets now :)

rspeer 9y ago
I would say nearly everyone in astronomy and education is in agreement right now that there are at least 9 planets. The only question is which ones they are. (Mike Brown, the "Pluto killer", is searching for the distant gravitational influence that he believes to be a legit ninth planet.)

tmalsburg2 9y ago

What's the posterior distribution over numbers of life forms in the universe under some conservative prior and after finding that this moon has life, too? (Plus assuming that these events are independent, which they are probably not.)

adekok 9y ago

> If life is there, completely disconnected from earth life, IIRC (I can't find the reference now), the "dinosaur killer" asteroid would put rocks from Earth into space. With sufficient velocity that they could reach nearby solar systems within 100M years. So from a strictly physical point of view, I would argue that the odds of Earth "infecting" Europa with life in the past 3 billion years are pretty much 100%.

scoofy 9y ago
>So from a strictly physical point of view, I would argue that the odds of Earth "infecting" Europa with life in the past 3 billion years are pretty much 100%. This is exactly why europa is so important. It's that the gravity well of jupiter is so great, that infection of europa is extremely unlikely, rather than being extremely likely. Europa would be a vastly better case for arguing separate origins of life than any other place in our solar system. Since earth has only existed for a short time in the grand scheme of things, and supposing that life indeed sprung here on its own, the odds of a random rock from a random few impacts landed on europa, rather than jupiter, in such a way to get to survive is absurdly small.
hackuser 9y ago
Europa is an extremely tiny target to hit randomly from Earth, probably made smaller by the fact that, in order to hit Europa, the object has to pass near Jupiter without getting pulled into it. On the other hand, there are billions of years of random attempts, as you said.
- adrianN 9y ago
  But there is a big lump of mass near Europa that tends to attract projectiles.
  - kerbalspacepro 9y ago
    You mean the wormhole with a blackhole on the other side?
  - 9y ago

IndianAstronaut 9y ago

If life was not there, I would wager that life is exceedingly rare in our universe.

otempomores 9y ago

A dark forrest teaming with live

otempomores 9y ago

A dark forrest teaming with live

jordache 9y ago

would you be really surprised though? I've already come to the conclusion that there is/was some sort of life within our solar system. Intelligent life is much more rare. If there is some evidence of that in our solar system, I would be floored

ziikutv 9y ago

Mermaids?

Symmetry 9y ago

It wouldn't really be surprising. Prokaryotic life appeared on Earth very quickly after the Earth cooled down. But it took a very long time after that for Eukaryotic cells to develop. Just going from Earth history I'd expect lots of planets with bacterial mats but very few with complex or multi-cellular life.

reubenswartz 9y ago
It seems like it happened "very quickly" compared to the evolution of eukaryotic cells and multicellular life, but it still took hundreds of millions of years, and it probably happened once or a handful of times, not all over the planet. I share your expectations, but it's hard to know if it's common even for bacterial-level life to arise.