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NASA study finds life-sparking energy source and molecule at Enceladus

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Re: NASA study finds life-sparking energy source and molecule at Enceladus

#21

Post by Sharlin »

Symmetry wrote: post #13
ianai wrote: post #2

yesterday: https://news.ycombinator.com/item?id=38652897 Hydrogen cyanide, acetylene, propylene, ethane, propene. There's bacteria that live off acetylene (though surely abiotic processes too). I suspect this indicates plenty of energy and complex chemistry on Enceladus. Some of those compounds are energetic while others (I think?) are combustion bi-products. Otherwise, I wonder when/if we'll ever see oxygen (O2) con…

I'd be very surprised if we saw oxygen. Photosynthesis took much longer to evolve on Earth than life did in the first place, and on Enceladus you have both a thick layer of ice preventing sunlight from reaching liquid water and also a much dimmer Sun in the first place due to how far away Jupiter is.

*Saturn, but yes. If there’s life, free oxygen would likely be incredibly toxic to it, just like it was to early life on Earth (and still is to some chemosynthesis-based ocean floor life).

Re: NASA study finds life-sparking energy source and molecule at Enceladus

#22

Post by idlewords »

superposeur wrote: post #6

This is intriguing and I’m very happy this exploration is being done. But, for decades, I’ve been reading reports of the discovery of evidence for the trappings of life elsewhere: water and organics and “habitable” exoplanets. These are valuable discoveries, but the tone of the reports suggest they imply life is about to turn up. It’s worth remembering that there is not one single shred of evidence that life has ever…

I would turn your logic around and say, everywhere we are able to look, we find evidence that life is more likely than expected. Until the 1990's it was an open question whether any other star had planets; as soon as we got the tools to test that, we found they were ubiquitous. As soon as we got the right instruments to Mars, we found signs of moving water, methane sources, and complex organic molecules in what is basically an Earth-like old lake bed. The moment PCR technology made it possible to do the search, we found a massive 'dark biome' extending many kilometers into the Earth's crust.

When you immediately find strong pieces of circumstantial evidence the moment you acquire the tools to start looking for something, the correct conclusion to draw is not "we have yet to find a shred of evidence", but that further searching is likely to be highly worthwhile.

Re: NASA study finds life-sparking energy source and molecule at Enceladus

#23

Post by superposeur »

idlewords wrote: post #22
superposeur wrote: post #6

This is intriguing and I’m very happy this exploration is being done. But, for decades, I’ve been reading reports of the discovery of evidence for the trappings of life elsewhere: water and organics and “habitable” exoplanets. These are valuable discoveries, but the tone of the reports suggest they imply life is about to turn up. It’s worth remembering that there is not one single shred of evidence that life has ever…

I would turn your logic around and say, everywhere we are able to look, we find evidence that life is more likely than expected. Until the 1990's it was an open question whether any other star had planets; as soon as we got the tools to test that, we found they were ubiquitous. As soon as we got the right instruments to Mars, we found signs of moving water, methane sources, and complex organic molecules in what is ba…

These factors are what I call the “trappings of life”. It is a completely open question (and I mean completely) how likely life is to arise spontaneously when these factors are present. One single instance of life elsewhere or successful abiogenesis in the lab would change that, but we have neither.

Re: NASA study finds life-sparking energy source and molecule at Enceladus

#25

Post by henry2023 »

superposeur wrote: post #6

This is intriguing and I’m very happy this exploration is being done. But, for decades, I’ve been reading reports of the discovery of evidence for the trappings of life elsewhere: water and organics and “habitable” exoplanets. These are valuable discoveries, but the tone of the reports suggest they imply life is about to turn up. It’s worth remembering that there is not one single shred of evidence that life has ever…

The universe is 13 billion years old.

Planet earth is 4.5 billion years old.

Life on earth started 3.7 billion years ago.

We sent our first radio wave just 125 years ago.

Probably life is not than unusual and we just don’t have a way to verify this (yet).

Re: NASA study finds life-sparking energy source and molecule at Enceladus

#26

Post by dylan604 »

ianai wrote: post #18
FL33TW00D wrote: post #15

Earlier quoted context omitted.

The lack of interest in abiogenesis in most circles is truly outstanding.

And here’s another thing. With how difficult it is to probe new physics, we stand to do a lot more research by simply inspecting all the observable universe than trying to build colliders.

Finding a new particle doesn't necessarily threaten strictly up held religious beliefs like finding life somewhere other than this rock

Re: NASA study finds life-sparking energy source and molecule at Enceladus

#27

Post by sz4kerto »

FL33TW00D wrote: post #15
superposeur wrote: post #6

This is intriguing and I’m very happy this exploration is being done. But, for decades, I’ve been reading reports of the discovery of evidence for the trappings of life elsewhere: water and organics and “habitable” exoplanets. These are valuable discoveries, but the tone of the reports suggest they imply life is about to turn up. It’s worth remembering that there is not one single shred of evidence that life has ever…

The lack of interest in abiogenesis in most circles is truly outstanding.

There's quite a bit of interest; e.g. ex-colleagues of mine have spent lots of effort on refining the 'chemoton' model. I think it's a fascinating subject.

"The basic assumption of the model is that life should fundamentally and essentially have three properties: metabolism, self-replication, and a bilipid membrane.[3] The metabolic and replication functions together form an autocatalytic subsystem necessary for the basic functions of life, and a membrane encloses this subsystem to separate it from the surrounding environment. Therefore, any system having such properties may be regarded as alive, and it will be subjected to natural selection and contain a self-sustaining cellular information."

https://en.wikipedia.org/wiki/Chemoton

https://www.nationalgeographic.com/premium/article/he-may-ha...

Re: NASA study finds life-sparking energy source and molecule at Enceladus

#28

Post by spenczar5 »

superposeur wrote: post #10
tshaddox wrote: post #8

Earlier quoted context omitted.

> It’s worth remembering that there is not one single shred of evidence that life has ever existed anywhere in the observable universe but Earth. I’m curious how your epistemology is working here. It seems to me that this will also be true in the future if we have found life on a hundred other planets. There still won’t be a shred of evidence of life anywhere else , and we still won’t have the faintest estimate of ho…

If, in a volume of space, there are N exoplanets and 100 spontaneously created life, then I’d crudely estimate the probability of life at 100/N for a given exoplanet. Currently, we have only an upper limit on the probability and barely even that. All observations are consistent with a probability less that 10^-40, meaning it certainly wouldn’t happen a second time in the observable universe.

How many exoplanets would you say we have proven have no life? You imply 10^40 exoplanets are known to harbor no life. That is probably vastly more than the number of planets in the observable universe (something in the wide region of 10^20 to 10^25).

Something like 5,000 exoplanets have even been discovered. We can’t cross off many of those as certainly lacking life.

Re: NASA study finds life-sparking energy source and molecule at Enceladus

#29

Post by fzeindl »

superposeur wrote: post #6

This is intriguing and I’m very happy this exploration is being done. But, for decades, I’ve been reading reports of the discovery of evidence for the trappings of life elsewhere: water and organics and “habitable” exoplanets. These are valuable discoveries, but the tone of the reports suggest they imply life is about to turn up. It’s worth remembering that there is not one single shred of evidence that life has ever…

I once heard: „The universe is unbelievably huge and unbelievably old so rare events happen all the time.“

I think it meant that even if life started itself accidentally by some unbelievably slim chance, this could happen somewhere else as well simply because the dice are rolled that often.

I think time is the factor here. When you take into account not only the size of the universe but also it‘s age, the chance that life started somewhere, somewhen and ended long ago could be larger than zero, even if we are not able to calculate it.

Re: NASA study finds life-sparking energy source and molecule at Enceladus

#30

Post by zvmaz »

superposeur wrote: post #6

This is intriguing and I’m very happy this exploration is being done. But, for decades, I’ve been reading reports of the discovery of evidence for the trappings of life elsewhere: water and organics and “habitable” exoplanets. These are valuable discoveries, but the tone of the reports suggest they imply life is about to turn up. It’s worth remembering that there is not one single shred of evidence that life has ever…

> It’s worth remembering that there is not one single shred of evidence that life has ever existed anywhere in the observable universe but Earth.

It is hard for me to believe that in the mind boggling vastness of space and time, we are the sole singularity in the history of the universe.

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