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> a fascinating world with a salty, subsurface ocean of liquid water—possibly twice as much as in all of Earth’s oceans combined.

If we brought water back a container of water from Europa would this be the largest amount of new water entering the earth since planets struck it billions of years ago?

I briefly googled it (I dont know much about this stuff tbh):

> The water on our Earth today is the same water that’s been here for nearly 5 billion years. So far, we haven’t managed to create any new water, and just a tiny fraction of our water has managed to escape out into space. The only thing that changes is the form that water takes as it travels through the water cycle.

Anyway interesting thought experiment.

Every once in a while, I get reminded that people don’t necessarily have a scientific background.

1. Water molecules are not indivisible, of course. Many biological processes will rip apart hydrogen and oxygen, or combine them back together, and have been doing so for billions of years. Industrial processes do the same. So there’s plenty of “new water” from oxygen in the air, etc.

2. New water/oxygen/hydrogen land on earth fairly regularly due to comets, which are usually slushy balls of ice.

> Every once in a while, I get reminded that people don’t necessarily have a scientific background.

This isn't necessary for your point and detracts from an otherwise useful clarification.

I find it helpful to remember. When covid was starting to spread I worried a lot about potential exponential growth and was confused why a lot of others didn't seem so worried. While there may be many reasons, one that came to mind is that they may not have learned as much about exponential growth as I had in electrical and computer engineering and in working with startups. So it helped me to remember not everyone has the same education and experience that I do, that we're all relatively ignorant, depending on the field.

There will always be people that don't know what you know and vice versa. It's a given fact of life. It's like forgetting that the sky is blue. Haha. I.e., I agree with you, but your statement is more humble than the last.

"but your statement is more humble than the last."

It also was a different person ..

I know it was a different person.

You are giving an example of the very issue you complain about. You worry about this not from a background of epidemiology, but another field entirely. Some of the people who were not worried were deferring to expert opinions they have read about the matter.

The vast majority of people dont really "get" functions or plots or line fitting

They took 7th grade math, but assert that y=mx is meaningless in real life and doesn't help them understand anything they have to deal with

Yeah. Originally when those people refused to wear masks I quietly wished them death. But after awhile I got more tired of hearing educated people pretend that their intellect was keeping them alive more than their economic leverage was. Rooting for the ignorant to die of covid was a bad look. Granted, we also had a president who said he loved the uneducated, so it all took place at a moment when that line could be drawn in a certain way. In any event, the snobbish castigation of people who don't understand science or math didn't help and actually hurt the cause of getting them to protect themselves and everyone else.

[dead]

As a non scientific person, I took no offense. Whilst it's fine to point these things out, it's important to remember that people come from different cultures, and often the intent is unlikely to be there to offend.

> detracts from it

I think you're assigning a moral quality to certain kinds of knowledge that isn't warranted.

I don't know what that means. The statement just wasn't useful and comes across as sassy and arrogant.

the most important thing though, is that that statement is true and verifiably so.

I am one of those persons that learned something by reading that comment.

assuming arrogance and sassyness in an otherwise neutral exposition of a true fact, to me means that, as usually happens, arrogance and sassyness are in the eye of the beholder.

Is the most important thing in communication that each statement is true, or that true information is successfully conveyed? If I prefaced this comment with true facts about how bad your life in particular is, I doubt you'd be ready to read the rest of it :)

  arrogance and sassyness are in the eye of the beholder

> Is the most important thing in communication that each statement is true, or that true information is successfully conveyed?

the former.

I, for example, am not native English speaker, so, for example, in this case should you learn Italian to the point where you are able to successfully convey the information to me, which could be "never"?

> f I prefaced this comment with true facts about how bad your life in particular is, I doubt you'd be ready to read the rest of it :)

you can try, but be ready to fail miserably. Also: I am very well aware how bad my life is, I would say that only an arrogant can think to know it better than me to the point that I will be surprised or shocked.

Do you think it's belittling to point out that someone may not have scientific knowledge? Ie, is the statement something beyond mere fact? What makes having scientific knowledge good, that you may infer that someone may think not having it is bad?

My first reading of the sentence in question was that it was patronising

In and of itself no. But in the context of responding to someone saying “your comment reminded me that some people don’t have a scientific background” can be read in a similar way to saying “your comment reminded me that not everyone on Hacker News is a genius”, even if that wasn’t the author’s intention.

I agree with you. I took it exactly the same way and thought it was unnecessary.

Point 1 above greatly understates the case. Water just sitting in a glass is constantly creating and destroying hydronium and hydroxide ions, and bare protons. Not to mention the carbon dioxide that gets dissolved as carbonic acid which can dissociate to bicarbonate.

On the other hand, its tough to talk about new water because under thermodynamics, all atoms of the same isotope at the same energy state are completely fungible, so it’s hard to say anything meaningful about the history of a molecule.

If a few water molecules are destroyed and replaced created over a long time then is it still the same glass of water?

The famous glass of Theseus’ water eh? https://en.m.wikipedia.org/wiki/Ship_of_Theseus

Is the Glass of Theseus half-full or half-empty?

Twice as big as it needs to be

Nothing is ever the same at room temperature if you are counting atoms.

True, but even Feynman talks about "new photons" when describing scattering.

Is the water I drink the same water I pee? Or does it get taken apart and put back together with different pieces?

Metabolism converts sugars and oxygen to carbon dioxide and water. Fire has the same inputs and outputs too! You can think of metabolism as releasing the same energy as fire but with more steps so our bodies can harness and use the energy via various other chemical reactions.

Most of the water from metabolism is released in your breath. Water you pee is mostly water you ingested via drinking and eating.

The water you exhale is just the amount of water that happens to evaporate in your respiratory tract/lungs. The water you urinate is whatever "extra" water is left over (based on a bunch of factors like blood pressure, how much stuff is dissolved in you blood, etc).

The water that leaves via your lungs and the water that leaves via your kidneys all had to get there via your blood. There's no distinction made based on the "source" of that water.

Yes agreed fair enough

> Most of the water from metabolism is released in your breath

And the reason for that is that air is bad for heat exchange and transport, water is much better, and evaporates! While the body passively cools in air (either directly when air is colder or via sweat evaporation when air is too hot) most of the heat exchange happens actively via breathing, which is nice because it's easy and quick to adjust, just by breathing faster or slower, so as to maintain 37ish C-100ish F while the body is continuously burning molecules. Without breathing we'd not only lack comburant (oxygen), we'd overheat pretty quickly!

The primary driver for your respiratory rate is the pH of your blood. For instance, metabolic disorders that result in a drop in blood pH will result in an increase in respiratory rate/depth (e.g. Kussmaul breathing). As far as I know (with a fairly deep anatomy and physiology background) there is no mechanism by which body temperature can directly influence respiratory rate. If your respiratory rate increased just to get rid of heat, you’d also be blowing off more carbon dioxide and would end up in a state of respiratory alkalosis.

As you mentioned, sweat is also evaporating water, and that is a much more effective way of dumping heat.

How do the kidneys identify the H2O molecules origin?

It’s a tagged Union with associated data (the molecule), released in edition Homo Erectus. Pretty nifty feature a lot of other species lack. Abstract Human Types are much more powerful than what Homo Go can offer, for example.

Same H2O molecules, different levels of other molecules mixed in with it.

It is possible to recycle urine into drinkable water. That’s what they do in international space station where water is very precious.

https://www.nasa.gov/mission_pages/station/research/news/wat...

They also do it in Singapore iirc.

I'm curious why this would be worthwhile: since Singapore is an island conventional desalination would seem easier than either coping with the witches' brew of sewage (random amounts of random chemicals) or the expense of plumbing urine separately.

Seem being the key word here; if it's plain sewage, there's affordable, scalable and relatively low energy ways to turn it back into clean drinking water, vs desalinization which requires a lot of energy still.

But it's not just sewage though, it's chemicals as well, e.g. from medication, plus whatever else gets flushed.

Exactly: all the sewage systems I know of process it enough to dump into a sea or river, where even if a downstream town draws drinking water from it the dilution with other water plus additional environmental chemistry reduces the purification problem.

In Singapore's case the sea is the obvious sink for treated sewage, which kicks it back to desalination. Except that I believe that Singapore's water comes across the causeway to the mainland in a pipe.

https://eu.usatoday.com/story/tech/2015/06/02/singapore-wate...

context

The Urine of Theseus, lol

> 2. New water/oxygen/hydrogen land on earth fairly regularly due to comets, which are usually slushy balls of ice.

This + the fact that we've seen microbes come back to life after being frozen in polar ice for millions of years always seems like the most obvious explanation for the origins of cellular life on earth to me.

In other words, what's the chance that the immense complexity of cells did evolve from a molecular soup here on earth VS the chance that it formed somewhere in the universe and found its way here (and many other places)

As a percentage of total water on earth, how many of the H2O molecules do you speculate came from comets or industrial processes?

Same question for the biological processes you mention.

I'm not a scientist; but water is used in photosynthesis, which is probably the main chemical reaction it undergoes. [1] says that the C3 cycle consumes 120 GT of CO2 per year, that's 2.7267×10^15 mols of CO2. C3 carbon fixation consumes one mol of H2O per mol of CO2, so that's 2.7267×10^15 mols of H2O. That's 5 * 10^13 liters. The USGS says there's ~1.4 billion cubic kilometers of water on earth (who chose that unit?), compared to 50 cubic kilometers for the C3 fixation. That's a lot of glasses, but not many oceans. Perhaps a bigger factor might be from back and forth reactions in the oceans and atmosphere, but I'm not sure how to estimate those (e.g., water converting between different acids or getting hit by light in the atmosphere).

[1]: https://bio.libretexts.org/Bookshelves/Biochemistry/Fundamen...

Definitely more than a glass of water which was the original question anyway.

> The water on our Earth today is the same water that’s been here for nearly 5 billion years.

We create tons of water as a byproduct of many industrial processes, that's "new" water. Of course in the grand scheme of things the quantities are inconsequential, so the statement is probably still generally true...

Is it truer to say "the hydrogen and oxygen on our Earth today are the same [...] 5 billion years"?

If those hydrogen and oxygen atoms had not previously been bonded into H2O, you would have to say this is “new” water, right?

Water of Theseus!

What if they bonded with different atoms? To get truly duplicate water it would need to find its partner(s, who knew water was poly), I suspect the odds are low :-)

Except water is H2O where the oxygen comes from plants and plants get it from water and the hydrogen comes from hydrocarbon fuels where the hydrogen comes from water again. So technically you can never create new water on Earth but you can bring in more from the space.

> Except water is H2O where the oxygen comes from plants and plants get it from water and the hydrogen comes from hydrocarbon fuels where the hydrogen comes from water again

I'm not a chemist, so I may be totally wrong here, but does a water molecule "care" where the source of its oxygen and hydrogen come from? If you brought oxygen from space, and hydrogen from space, couldn't you then create new water on Earth?

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Perhaps I misunderstood your original comment. I interpreted what you said as meaning that the hydrogen and oxygen atoms that make up an H2O molecule had to be derived from H2O molecules.

After all, your words were:

> oxygen comes from plants and plants get it from water and the hydrogen comes from hydrocarbon fuels where the hydrogen comes from water again

Then:

> technically you can never create new water on Earth

I asked the questions in good faith, even while knowing that the origin of the individual atoms has no bearing on whether an H2O molecule is H2O or not. I wanted to give you an opportunity to perhaps share something that the rest of us didn't know.

Your response was to ask about my education and how old I was, two data points that I can confidently claim have zero relevance on how water molecules are formed.

> technically you can never create new water on Earth

This is absolutely incorrect. Water can be created on Earth and is being created constantly from various processes. One of those processes: burning any hydrocarbon based fuels (aka, fossil fuels). You can see it for yourself - run any internal combustion engine and you'll see water dripping from the exhaust pipe.

Please pay more attention to the user names.

Comets do fall from time to time, and Earth collects 5000 tons of debri from space each year. So I imagine Earth does gain a few tons of water from time to time.

> Earth collects 5000 tons of debri from space each year

That is a lot more than I would have guessed. I had thought that we were very slowly leaking precious resources by sending rockets into space, but I guess we're actually still gaining resources on average.

(At least, I don't think we're sending 5000 tons beyond the atmosphere every year).

https://en.wikipedia.org/wiki/Earth_mass#Variation

Oh good point, I didn't think about Comets.

It depends on your definition of creating new water.

When we extract crude oil from ground, hydrogen is made as byproduct. Similar with other industrial processes. That hydrogen released in atmosphere burns with oxygen to make water.

So one could say that is new water.

The sun is a big hydrogen ball, and some of the big sun flares may bring new hydrogen atoms to Earth. Which then end up oxidized into water, hence new water.

https://www.nasa.gov/mission_pages/stereo/news/Solar_Flare_S....

Hydrolox rockets have been making millions of gallons of new water on earth.

Even burning gasoline creates some new water.

In fact all fossil fuels! When you split the carbon parts from the hydrocarbon, most of hydrogen parts end up as water. For every tonne of CO2 that's ever been emitted, there's a corresponding mass of water for which the hydrogen part was previously sequestered.

All fossil fuels except coal, which is a pretty big one.

Why not coal?

It's approximately pure carbon, not hydrocarbon.

Burning gasoline releases more h2o than co2 - think about that for scale

Don’t commercial hydrogen fuel cells create water as a byproduct?

Yeah, but you make hydrogen fuel out of water, so you're kinda just playing accounting games with the water.

Hydrogen is mostly made by steam reforming methane, with half the hydrogen coming from the water and half from the methane.

But then the fossil methane was made by bacteria decomposing carbohydrates and the carbohydrates were made by plants photosynthesising water and carbon dioxide.

So it all comes from water in the end, but some of it has not been water for hundreds of millions of years!

Great video I just happened to finish:

https://www.youtube.com/watch?v=vjDnh7zfO98

"Where did Earth's water come from?"

No, water is brought to earth by meteors and comets.

This is why I roll my eyes at alarmist talk of various processes "consuming X zillion gallons of water".

Water is much stronger than that. It just passes through our processes and will outlast us all.

And I roll my eyes at comments like this.

There's a huge difference of usability between different water sources. You can't irrigate your orchards with salt water from the ocean. You can't bathe in waste water from most manufacturing plants. You can't drink ground water that has been contaminated by fracking.

There is a finite amount of potable water. There is a finite amount of usable water for agriculture. Pointing at all of the water on earth and acting as if it's all immediately usable without significant, costly barriers is silly.

I wonder what the economics are of a massive centralized desalination plant in Africa powered by a Sahara mega-array of solar panels. Oil is transported via pipeline, what about water?

Your sort of responses to climate alarms are always the most disingenuous.

We are consuming water from places where it has been relatively static, at rates far beyond its natural replenishment rate. THAT'S the issue. Yes, this is a closed system, and the human circulatory system is a closed system. But it's bad if you drain the blood from your brain faster than it is replenished.

It's only bad if there aren't undiscovered sources and/or processes we can use in the future to produce more water. It's technological optimism, not disingenuousness.

That sounds like it's beyond optimum into foolishness. I could possibly win the lottery one day, but I'm not going to live my life as if it's guaranteed.

Your analogy is an extreme example of the principle I'm referencing. Taken to a similar extreme, your argument is that we should choose who lives and who dies, through the limitation of the resources required for growth.

They are just being realistic, their example isn’t extreme (though yours is).

It is entirely possible with our current level of technology to adjust to the realities of the physical limitations in the world as we know it, without needing to resort to picking “who lives and dies”.

If those adjustments are to be made, they should be in increases in supply, not artificial constraints, that's my argument. Winning the lottery is imo more likely than finding a way to limit growth without draconian/totalitarian measures.

Saying there might be fixes for this in the future is also disingenuous.

It's like saying military burn pits are okay because there may be medical advancements in the future that can be used to treat afflicted soldiers.

Arguing against optimism is arguing against the history of science. We have cures to diseases that were declared unavoidable divine judgements, we have achieved feats of engineering that would be unimaginable a century ago. I am not arguing for the deapoilation of the planet. We should preserve our resources as best we can. But future growth requires the usage of what resources we do have, in to achieve outcomes and efficiencies far better than we can imagine.

I do agree though, if science wasn't verifiable, it would sound like a pyramid scheme.

Technological pessimism underestimates the rate of progress, but technological optimism routinely overestimates it. In the 50s people thought we would have superintelligent robots, flying cars, moon colonies and cold fusion by year 2000. In the 60s people were optimistic that we would eradicate all diseases in the near future. Right now some people believe the singularity will happen in the next decade. What could possibly happen in the next century that would be "unimaginable" to them?

If you showed today's world to an optimist from a century ago they would see many wondrous things they would never have thought of, but they would also fail to see many of their predicted advancements. And I do think that what optimists predict is usually far more impressive than what actually comes to fruition. That's not to say the pessimists are right, but the optimists simply don't have the track record you seem to think they have.

Technological advances are nice, but you can’t just assume they will happen. There’s no law or axiom that says we will discover something new, and certainly not on any time scale that we could plan against to avoid problems we predict today.

Based on past trends, it's much more likely we will discover new sources and methods of resource generation, than not. Diamonds were rare, now lab created, electricity was once sparse now ubiquitous. The trend is obvious

I'm not being disingenuous. I honestly have a different analysis and opinion than you.

You’re entirely missing the context of what you call “alarmist talk”.

The issue isn’t that the water will cease to exist, or that the planet will literally be destroyed. It is that our way of life is unsustainable and actively degrades the future quality of life for us in the future (and our children).

You can compare our mindless pumping of water from the ground to the ignorant farming practices that lead to the dust bowl. If we don’t use our knowledge to take steps to avoid running out of usable water by using it less and more intelligently now, we will come to a hard point in the future.

Which takes cooperation and empathy for everyone’s situations and the overall reality in front of us.

“Water” is overloaded. They may mean drinkable water.

Yeah man, water your vegetables with sea water, they'll love it.

> NASA's Webb

I guess it may be technically owned and primarily operated by NASA, but it was developed from the start as an international project: https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#Par...

I also hate American-centrism but it seems kinda justified here - they do go out of their way to mention ESA and CSA at the end, as well.

From that article:

  NASA's lifetime cost for the project is[when?] expected to be US$9.7 billion, of which US$8.8 billion was spent on spacecraft design and development and US$861 million is planned to support five years of mission operations.[112] Representatives from ESA and CSA stated their project contributions amount to approximately €700 million and CA$200 million, respectively.[113]

Fair enough.

Why does one random Jovian moon have so much water? And why not all similarly sized rocky bodies in the solar system?

Isn't this even stranger than Earth's water?

There's also https://en.wikipedia.org/wiki/Enceladus so it's not just one random moon.

Sticking with just the Jovian moons, both Ganymede and Callisto are thought to have subsurface oceans too.

Ganymede's oceans might be the largest in the entire Solar System.

1. https://en.wikipedia.org/wiki/Ganymede_(moon)#Subsurface_oce...

2. https://en.wikipedia.org/wiki/Callisto_(moon)#Internal_struc...

800km deep. Oof.

Seems like an ocean world could develop intelligence but technology would be quite difficult.

Our technology would be quite difficult, we might not even be able imagine what form an alien race's might take.

Technology is technology, it's about exploiting the laws of nature to do things.

If you want to create refined metals you'll need to heat it, you'll need a source of heat, and you'll need to isolate it from the surrounding water long enough to finish the process.

Being underwater makes a lot things much much more difficult or impossible.

That's even ignoring your species won't be incidentally exposed to sources of easy energy like fire occurring naturally before learning to create it yourself.

There's certainly workarounds and alternatives that could make it _possible_ to develop technologies like fire, metallurgy, complex chemistry, etc. but they'll all be so much harder to discover and do that no early civilisation would consider the required experimentation worthwhile.

Again, you're thinking human centric. Maybe they could do amazing things with non metallic materials which we haven't needed or which haven't been practical for us due to the different circumstances.

there are some pretty cool scifi books that look at how an aquatic species might develop technology. the "ringworld's children" involves a species that develops on a frozen world with an ocean beneath the ice.

A recent episode of Planetary Radio discussed this. Io could have been a water world as well, once.

https://www.planetary.org/planetary-radio/2023-lost-oceans-a...

Rocks can consume a lot of water as well. Their chemistry means they can absorb a lot of water in their mineral structure so water isn’t just about surface oceans but also how much is inside a celestial body as well.

There is a lot of water in the solar system. Comets are mostly water, for example.

Here is a great series about the water in the outer solar system & the rest of the Universe.

You might have forgot something.

Hi, a link? :)

Does material tend to settle and accrete at different orbits due to weight/density?

Probably came from elsewhere and got caught in jupiters orbit

Is the significance of CO2's presence 1) it's necessary ingredient for (our) life, 2) it's a likely biproduct of life, or both?

The first one. It can be produced through non-biological processes and is fairly stable, but is also necessary for "life as we know it".

Gaseous oxygen would be 2 - it's highly reactive, so if you detect it in an atmosphere, it means there must be some kind of activity going on that replenishes it. On Earth, it's what life does.

Note that mars's atmosphere has more CO2 in it (per unit volume! Despite having almost no atmosphere) than Earth's does. Definitely not 2.

A rapid change in CO2 concentration could be a clue that something such as life is rearranging the molecules on a planet. In fact, I think the aliens have been monitoring us with a spectrometer for a few million years, and have guessed that we're here.

Indeed, and looking at exoplanets through a spectrometer is a possible way for us to discover life in our stellar neighborhood, should it exist. But as I mentioned in my parallel reply, oxygen is better than CO2 for initial screening, because its very presence on a randomly observed planet indicates something wonky is going on - there shouldn't be any, unless it's being actively replenished by some process, as otherwise it would've oxidized other matter both on the surface and in the atmosphere, and be long gone by the time we pointed our telescopes at that world.

Europa is definitely the most exciting part of the solar system that sparks imagination. Literally 100s of miles of pitch black ocean with thermal vents, ripe for life. Getting kiddy thinking about the leviathan sized aliens roaming the deep ocean of Europa. Does anyone else feel this way?

Well technically they would just be Europeans.

Technically, they’d be Europans. ;p

Are you sure, I think they would be called Europaeans.

To solve your dillema as a Greek. Both the continent and the planet have the same name. Europeans it is.

While on the subject of etymology, spelling the Greek word “dilemma” (δι+ληπ+μα) incorrectly does not help with providing a definitive answer as a Greek. I'm not starting a flame war, I just make an observation (and as it happens, I'm a fellow Greek).

Yes, the word “European” (inhabitant of Europe) is rooted on the Greek word Europē, Zeus' mythical mistress (one of many), after whom both the continent and the satellite were named, but is the “-ean” a proper transcription from Greek?

Perhaps “Europaean” could be the better answer to the question we discuss; after all, in English the continent's name is a modernized “Europe” while the satellite stays closer to the intermediate Latin as “Europa”, and since this discussion is in English, I feel that the difference in suffix justifies a different label for the inhabitants of the satellite.

I think it was a joke, not a argument from authority as a greek :)

That said, I think ChatGPT is right here:

  ...the term "Europans" seems the most appropriate choice for the inhabitants of the Jovian moon Europa. It aligns with the linguistic patterns used for other celestial bodies, maintains clarity by avoiding confusion with "Europeans," and respects the Greek origin of the name "Europa" without introducing non-standard formations.

  Mercury: Mercurians
  Venus: Venusians
  Earth: Earthlings
  Mars: Martians
  Jupiter: Jovians
  Saturn: Saturnians
  Uranus: Uranians
  Neptune: Neptunians
  Pluto: Plutonians
  Moon: Lunarians
  Io: Ionians
  Europa: Europans
  Ganymede: Ganymedians
  Callisto: Callistans
  Titan: Titanians
  Rhea: Rheans
  Iapetus: Iapetians
  Triton: Tritonians
  Eris: Erisians
  Ceres: Cerians

That doesn't seem like a very Greek spelling of dilēmma.

There are currently two Jupiter moon exploration missions either en route or about to launch. Oddly, the European one (JUICE, launched earlier this year) will focus on Ganymede, while the NASA one (Europa Clipper, launches next year) will focus on Europa.

Or Europaens?

Europa Report (movie): https://www.youtube.com/watch?v=avzqYgtpdMQ I enjoyed it ^^

I was thinking that just now and will rewatch this evening! Any other recommendations of the same vibe?

Great film with the suspense and tension of Aliens.

Great movie, smart script and they did a great job without huge budget

From an Arthur C. Clarke novel:

> ALL THESE WORLDS ARE YOURS - EXCEPT EUROPA.

> ATTEMPT NO LANDING THERE.

So yes. Clarke thought it was special also.

Well, kinda, eventually. The book of 2001 points Discovery 1 at Iapetus, a moon of Saturn. Evidently, the special effects crew for the movie couldn't do a convincing job of faking Saturn because of the rings so they did Jupiter instead.

Then when Clarke did the book for 2010 he retcon'd it to match the movie.

I'm pretty sure that Clarke stated somewhere in the preface that each story in the Space Odyssey series doesn't necessary happens in the same universe and thus that's why there's a difference between places in books

Nevertheless, Jupiter as the biggest planet within our star system being forced to collapse into a small sun feel extremely right

It's also one of my favorite sequences in the 2010 movie of Space Odessey series (which IMO, works a lot better as an actual movie pacing wise). Just something about the tension gets captured really well there, without their being any sort of actual threat (since it's a robotic probe).

Funny that the Clipper probe is still only flying by, attempting no landing.

Don't forget about Enceladus. Also a massive ocean with the added benefit of shooting enormous geysers into space. Would be wonderful if our solar system had at least 3 worlds with ocean life.

https://solarsystem.nasa.gov/moons/saturn-moons/enceladus

imagine if we could harness the power of the sun and basically direct extra heat towards target moons and planets via a mirror system or something and basically make any body in our solar system human habitable warm.

I'd imagine this could also be weaponized against dangerous asteroids, as the heat laser or whatever could cause a change in direction.

or terrible news a la great filter arguments

Except those are utter nonsense. The distances involved, the speed of light and inverse square laws mean we wouldn't expect to have detected aliens yet if they are there, so we can't deduce anything about their existence from the fact we haven't detected them. The "Fermi" "paradox" is like someone locked in a bathroom going "OMG I can't see anybody! Everybody on earth must have died!!".

> The distances involved, the speed of light and inverse square laws mean we wouldn't expect to have detected aliens yet if they are there

That’s not true at all - simple assumptions would make it likely we would have encountered intelligent life if it evolved in the past in this galaxy.

We don't have the technology to detect signals similar to our own from the distance of even the nearest stars [1], and there is no reason to assume that more technologically advanced civilisations will generate vastly larger signals. Therefore the absence of detection to date tells us nothing, except to place an extremely generous upper bound on the power of signals they generate.

[1] https://www.seti.org/press-release/can-et-detect-us - where a SETI researcher concludes an alien civilisation around a nearby star would require technology much more advanced than ours to detect us. (And what technology we do have has been pointed at a vanishingly small fraction of the planets in the galaxy.)

We wouldn’t need to detect signals - life arising only a few hundred million years earlier than us would easily have been able to send physical artifacts/vehicles/harvesting to every system in the entire galaxy if they had interstellar travel.

If life were common enough that it has evolved multiple times in the same solar system (excluding panspermia) then this becomes almost a certainty that it should have occurred

What a big assumption to make though. Billions of years of life on earth and an object was first put in space what 80 years ago? This technological age of ours could very well just be a blip. Its far more likely based on our own planet that intelligent life does none of these things. We might not have civilization at all if we didn’t happen to farm, we could both be preparing for our morning hunt and foraging just as easily as we are preparing for work today, if events happened only slightly differently. N=1 here. Our trajectory is no generalized model.

Yes, it is possible that there is a large filter between developing life and getting to where we are. I can't deny that that is a possible explanation for the observed Fermi paradox.

But finding independent life on other planets would eliminate a whole class of great filters, making it more likely the filter is either as you said or that it is ahead of us. It is bad news imo if it is more likely than before that the filter is ahead of us. And that is unambiguously the case if we were to find life on another planet. Not proof positive it is ahead of us, but it shifts the probabilities.

And yes, it took billions of years for life to evolve, but if we find life in our solar system, that is potentially billions of opportunities for life independently evolving.

All you need is one single civilization to develop von Neumann probes and then they’re everywhere in the universe (or at least Galaxy). If life really is so ubiquitous as to be found in 3 different planets or moons in our solar system then we’re totally screwed.

How many different life forms have there been on earth? Billions? How many of these have made von neumann probes? Zero. All these assumptions about how intelligent life should look are always so anthropocentric and rooted in assumptions we make based on supposition or even sci fi stories. Meanwhile, your dog is an example of intelligent life, and it engages in none of these pursuits.

Why do people insist that intelligent life had to take the turns we took over the last couple thousands of years? Intelligent life is far more likely to look like how humans have lived for the last couple hundred thousand years than the last few thousand. I’d argue a flock of birds qualifies as intelligent life.

It makes sense temporally.

If you have a species that is intelligent and has the capacity to evolve to more and more sophisticated tool building, then that will build on itself. If life is so common that it has arisen independently on other planets in our solar system, it would be likely that these intelligent species would have arisen hundreds of millions of years before us.

And even if most don't advance to interstellar travel, it really only takes a few expansionary ones if they were sufficiently long ago that we would have seen evidence. Again, if life is so common it is on other bodies independently in our solar system, this should have happened probably.

> The "Fermi" "paradox" is like someone locked in a bathroom going "OMG I can't see anybody! Everybody on earth must have died!!".

I’m going to try this today just to see how my wife reacts.

It's also utter nonsense because we have already detected UAP NHIs and are gradually beginning to understand them as the stigma fades away.

Could you have leviathan sized animals with no phytoplankton? Seems like thermal vents would provide a lot less energy than the Sun, but I’m really out of my depth.

> Could you have leviathan sized animals with no phytoplankton?

Yes. See e.g.:

https://www.biointeractive.org/classroom-resources/how-giant...

These aren't "leviathan-sized" but they could easily provide food for something that big. The base of this food chain would be chemosynthetic bacteria. After that, energy is not the limiting factor on size.

Broadly, yes, but chemosynthetic organisms tend to be benthic (afaict, IANA marine microbiologist), so they can stay close to their food source. So something big that feeds on them would probably be a grazer more than a swimmer. Unless, perhaps, they need to swim between vent sites or something...

So I asked my friend who knows things about marine microbiology and she was actually pretty optimistic about free floating chemoautotrophs as the base of a food web. You just need enough chemicals dissolved in the water (which I guess is how they grow them in the lab). Some other ideas we discussed were bacteria growing on suspended particles and as endosymbiotes in larger animals like the aforementioned tube worms. So yeah, leviathans are on the table.

If it turns out to not have life, we should introduce Earth life and let evolution run amok there.

I realize some conservationists disagree.

_highly_ recommend the "Red Mars" series - deals with questions I never thought of before, namely "to what extent should we preserve the surface of other planets?

This could be the cause of our presence

The Venusians certainly weren't conservationists.

Gotta pay it forward!

I mean if it's confined to geothermal vents I'd think bugs would be the absolute outside limit for most complicated life, and realistically it's probably prokaryotic life if anything.

That would still be mindblowing, and also horrifying when you think about the Fermi paradox.

Wondering if we could eat fish born on Europa and if there would be any ill effects.

No doubt on some Europan version of HN right now they're posting wondering the same thing about us.

Probably a prerequisite is their biosphere has a common origin with ours, so the biochemistry is shared. Otherwise you wouldn't fare much better than someone eating random chemical compounds from an organic synthesis lab.

This is where chirality rears its ugly head.

I am excited to see what can be in Europa's deep oceans. But I've always felt Enceladus would be a better place to start looking. Europa requires a lot of burrowing into ice, whereas Enceladus could reveal some of its secrets with a couple of proper flybys.

technically, most exciting part of our solar system is Earth. Have you never been to Vegas?

That’s bad, I heard Carbon is pretty bad to any environment

It's okay, as your savior, I have credits to sell you.

People must understand the following: if we find One Microbe in such environment, it basically means life is common in the universe. The other thing people must understand: "life" and "fully evolved intelligent life" are two very different stories.

It doesn’t. Due to proximity to earth it’s far more likely to share some common ancestor or precursor chemical reaction.

Unless it has a common ancestor to life here. Then we still have to figure out if it started in this solar system or not.

Of course, I was implying that such possibility would have been properly excluded.

Linda Moulton-Howe covered some testimony from "insiders" that alleged that there is an octopus type species living under the ice covered ocean of Europa. I have no idea which Earthfiles episode this was in, but cool if true.

Did they use a secret trillion dollar X ray glass telescope to peer through Europa's miles thick ice sheet and see?

Skepticism is warranted, but there's no need for mockery. It only insults your humility in front of the great mystery.

But to answer the question: I think they drilled down there, or sent a probe, but equally it could have been something told to them by an ET. But I can't recall the specifics.

Mockery is deserved in this case. Not every cartoonish and outlandish claim needs to be engaged with seriously.

You don't understand tho: you're not qualified to judge or disqualify it. That's why mockery is not only undeserved but inappropriate. That's why mockery here only humiliates you in front of the great mystery. You say you know the universe's possibilities? The universe would disagree with you, and you'd lose.

That's why you need openness, curiosity and skepticism to stand in front of these things. Those who mock this just look like arrogant fools. And you're not that, so that's why you need to respect yourself more, by not mocking these things that you're not qualified to disprove, but remain open in front of them, as possibly uncomfortable as that may be for whatever reason.

I hope you understand that. Also you need enough openness to understand that not everything outside of the common ken is equally (a very mocking description) "cartoonish and outlandish". A more profitable line of inquiry and discussion might be: What are your thoughts on the possibilities of there being an octopus-like species under the surface of Europa?

Mockery is definitely acceptable when someone makes outlandish claims. You are totally justified in laughing at the spying spaghetti monster because its point is to make fun of the ludicrousness of some people’s beliefs.

What are my thoughts on an octopus like species under Europa? What are YOUR thoughts on lizard people living inside Earths core? If we want to acknowledge every fantastical claim with zero proof we will just have created another religion not pursue science.

Hey Ramraj07, do you really believe what you're saying? Let's dig in a bit. The idea of lizard people at the Earth's core sounds out there, but let's consider the facts. We don't fully understand what the Earth's core is like. It could be a high-pressure, metallic, molten phase. But we're largely in the dark here; it could be anything.

Now, if you think about honeycomb Earth, filled with caverns and caves, things get more interesting. We know microbes inhabit the subsurface in abundance, types we don't see on the surface. So who's to say what else might be down there? It's a mystery, and dismissing it outright is a mistake.

Now, about lizard people living inside our version of Earth: I believe they could exist. I know that in an alternate timeline where Earth's history took a different turn and lacked the asteroid which 65 million years ago provided the opportunity for mammals to evolve into apes and humans, it was reptiles that evolved into an upright humanoid form. These alternate timeline reptilian humanoids are indigenous to their own version of Earth and exist in a dimension overlaid with our own. Earth humans from this timeline encountering these upright reptilians and their more volcanic planet via transitory dimensional portals have mislabelled them devils and demons, and their world? You guessed it: "hell". So, is it that far-fetched to think that some communities of indigenous terran reptilian humanoids might exist in our timeline, in our dimension? Reports from religions, government insiders, and the public suggest it's possible.

Switching gears, what do you think about octopus species living beneath the ice of Europa? And, why the cynicism? Did you once believe in these things but grew disheartened due to disinformation campaigns? Skepticism is healthy; cynicism is not. Don't let fear or social pressures derail your curiosity.

So why not rejoin those of us willing to consider the unexplained? You'd bring a lot to the table. Humor is good, but mockery doesn't serve anyone, especially when we're talking about the unknown: it only insults your humility in front of the great mystery. And you're better than that, Ramraj07--so act like it, dude! What are your thoughts, man?

I don’t reconsider outlandish theories because of misinformation campaigns I do my own research. My research and learnings have showed that the temperature and pressure increase quite dramatically as you dig deeper and a few miles in it’s too hot for even metal to stay solid. So yeah I can personally confidentially disregard the hypothesis that there’s places where complex beings can exist deep inside earth unbeknownst to us. We are not in kindergarten giving gold stars for effort. Especially poor ones at that.

Of course not - much more traditional methods - interrogation of their spies on Earth, cuttlefish.

That's quite funny, haha. But I think the story might be related to this, the insider told Linda this, and I can't recall directly, but the info may have been told to the insider by an ET.

Can Webb image Europa?

As others have said, you're looking at the image. We'll have to wait for a bit before we get some really good images of Europa. From Google:

NASA's Europa Clipper is the first dedicated mission to explore a world with a global ocean, other than Earth. The spacecraft is scheduled to launch in October 2024 and will arrive at Europa in 2030. The mission will study Europa's surface and interior to determine if it has the ingredients to support life. The spacecraft will make about 50 close flybys of Europa while orbiting Jupiter.

Also see some of the images from Juno if you want a better look at the moon.

> scheduled to launch in October 2024 and will arrive at Europa in 2030

wow, when you see dates like this it really puts things into perspective! a six year trip! any idea of how much of the trip is acceleration vs. deceleration?

Not exactly what you're asking, but it might be helpful to know that they're not planning to take a direct flight there. NASA is planning to use gravity assists off of Mars in Feb 2025 and Earth in Dec 2026. They can launch it MUCH more cheaply that way but it'll take about 3 years longer than a direct flight.

There's an animation of the planned trajectory on Wikipedia: https://en.wikipedia.org/wiki/File:Animation_of_Europa_Clipp...

> Can Webb image Europa?

The implication by the presence of "Europa Carbon Dioxide Distribution" (NIRCam and NIRSpec IFU) images on the NASA release is that yes, it can.

Yes, the NIRCam images in the article are from the Webb telescope.

The article is very precise:

"Both teams identified the carbon dioxide using data from the integral field unit of Webb’s Near-Infrared Spectrograph (NIRSpec). This instrument mode provides spectra with a resolution of 200 x 200 miles (320 x 320 kilometers) on the surface of Europa, which has a diameter of 1,944 miles, allowing astronomers to determine where specific chemicals are located."

Wikipedia article about the NIRSpec:

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

There’s an image of Europa from Webb in the article.

It's less clear than I'd expected. Is that image deliberately downscaled so as to not reveal the true capabilities of the telescope optics?

No, they're quite open about the capabilities of the optics (see https://webb.nasa.gov/content/forScientists/faqScientists.ht...). It's just that Europa is very far away.

Webb's mirror system has an angular resolution of about 0.1 arcseconds. Earth is currently about 630 million km from Europa (Webb is only 1.5 million km away from earth). Because the sine of theta is approximately equal to theta for values of theta near zero, you can get the diameter of a 0.1 arcsecond cone at x km from Earth by multiplying by 0.00000485 = sin(2pi/3603600).

0.1 0.00000485 * 630000000 = 305 km

The article says the pixels are about 320 km, so the math works out pretty close (for astronomy).

Those magnificent images of black holes and galaxies that are way more distant, but also way way bigger. This isn't downscaled when you compare it to gorgeous, sharper images like those at [1], a 340 light-year wide multi-image mosaic of the Tarantula Nebula, which is "only" 161000 light years away, that width is 1/500th the distance and Europa's width is 1/20,000th the distance.

In space, intuition about distances that you've built up from using your eyeballs on human-scale terrestrial objects just doesn't work, you've got to do the math.

[1]: https://www.nasa.gov/feature/goddard/2022/a-cosmic-tarantula...

For the conspiracy theorists: this is the same reason why we can't just point Webb at the moon and get pictures of the lunar landing sites. In terms of arcseconds of the Webb's FOV, the moon landing site is much smaller than these distant galaxies (which blows my mind just how big those distant "objects" are).

We can image the lunar landing sites with lunar orbiters, though. Footsteps and all!

https://www.nasa.gov/mission_pages/LRO/news/apollo-sites.htm...

Right -- they are a bit closer than Webb :D

You obviously mean the fake lunar orbiters. And those footsteps are not human anyway, it's the Moonfoot. /s :)

Not just that, its infrared sensors require shielding from Earth/Moon (let alone Sun) heat to function as designed, and it would mostly see the dark side of the moon anyway.

This reply is why I love the audience on HN. Thank you for your detailed comment.

Nice! Yeah, some things in the sky are actually way bigger than one might think. The first time I saw this composite of the moon and andromeda it kind of blew my mind.

https://i.stack.imgur.com/gMZb3.jpg

It’s probably a mental trick but once you know where the Orion Nebula is you can also just barely make it out with the naked eye.

https://www.reddit.com/r/Astronomy/comments/aecbbl/the_orion...

This is what it looks like ‘live’ through an 11” telescope if you try to hold your phone with your hands lol, and you can see the ‘fuzziness’ of it, not the color:

https://imgur.com/a/nt6FdLV

I wish every website I visited had comments of this quality…

This is why I only read Hacker News these days.

Thanks for the detailed comment, that is incredibly helpful info.

You can probably even find the raw data for the image on one of NASA's sites soon if not already available. This isn't a spy satellite where there's a strategic need to hide the capabilities of the optics. If anything, it's more valuable to show off the capabilities because of how it's somewhat of a prestige project.

No, I doubt it.

Europa is fairly small and very far away.

For reference, the best photos we had of Pluto prior to the fly-by were from the Hubble telescope, and were even grainier.

Webb has two main instruments and one of them is not very high resolution (but I think it’s the one that gets good spectral data). When you browse the raw Webb images on the nasa website you see a mix of high res and low res images and they are each attributed to one of the two instruments.

No. JWST is not a spy satellite. Everybody gets the images as measured. Different instruments have different resolutions.

It's as designed:

"Both teams identified the carbon dioxide using data from the integral field unit of Webb’s Near-Infrared Spectrograph (NIRSpec). This instrument mode provides spectra with a resolution of 200 x 200 miles (320 x 320 kilometers) on the surface of Europa, which has a diameter of 1,944 miles"

In addition to moons being big and far away, the specific instrument here (a spectrograph) is not very high resolution-- at least spatially. For each "pixel", it measures the brightness of many wavelengths of light.

No, moons are not very big.

Only if your IP address has been listed as suspicious. For the rest of us, we see an non-manipulated image.

Is this post trying to imply they found aliens and are hiding them?

No, just some black monoliths on the surface ;)

Not reveal the true capabilities? Is this an RPG reference?

I’m not sure, it’s the sensor that worries me. The sensor isn’t even big enough to image uranus.

“All these worlds are yours - except Europa.

Attempt no landing there.”

You have been warned guys… ;)

Honestly, the only thing I wish to see before I die is a submarine mission to Europa or Ganymede. It would be even more mind blowing and an amazing achievement for humanity, and the search for extraterrestrial life.

That, and the dragonfly-helicopter-thing on Titan. Have you ever seen the Sun set on a methane lake?

It's time for a rewatch of Europa Report (2013).

A Europa submarine mission is a good bucket list, but don't sell us too short.

* Humans on Mars * Room temperature Superconductors and their effects on humanity. * Sustained Fusion Power for the masses. * General Artificial Intelligence * Human brain-computer interface. * Full reversal of climate change. * Extended human lifespan. * Curing all forms of cancer. * Universal translator for all human languages. * Discovery of extraterrestrial intelligent life. * Understanding dark energy and dark matter. * A true virtual reality, indistinguishable from reality. * 100% renewable energy global infrastructure. * Establishing a lunar base. * Sentient AI companions. * Discovering the origin of life.

If you elect me, I will make all these come true!

I would like to see a solar gravitational lens telescope built in space to look at distant exoplanets with the highest resolution possible.

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

although last time I brought this up on HN someone explained to me it'd be very expensive, need to be huge, and it'd likely only point at one planet per lens, and the image would still be pretty blurry :(

> 2020, NASA physicist Slava Turyshev presented his idea of direct multi-pixel imaging and spectroscopy of an exoplanet with a solar gravitational lens mission. The lens could reconstruct the exoplanet image with ~25 km-scale surface resolution in 6 months of integration time, enough to see surface features and signs of habitability. His proposal was selected for the Phase III of the NIAC 2020 (NASA Institute for Advanced Concepts). Turyshev proposes to use realistic-sized solar sails (~16 vanes of 103 m2) to achieve the needed high velocity at perihelion (~150 km/sec), reaching 547 AU in 17 years.

https://www.nasa.gov/directorates/spacetech/niac/2020_Phase_...

> Universal translator for all human languages.

We are pretty much already there, though there is room to improve, it's an amazing accomplishment though that I think we take for granted.

Alright Elon, calm down

I don’t want humans on Mars. What would they do there? Sounds like a terrible idea.

> Curing all forms of cancer.

Likewise, solving antibiotic resistance.

About half of these I don't care for, but the submarine mission would be cool.

"I can see Europa from my house!"

We've got plenty of hard problems to work out before we can haul off to Europa, at least with people. Solving those problems will be more impactful in the long run than whatever we might find there. I mean, you could drive to Alaska for an ice cream cone, but the fact that you can get one out of your fridge is more impactful to you personally. Also, I try not to get too caught up in imagining specifics. Often we overlook the valuable and surprising because we are looking for the wrong thing: the thing we expect to see.

It's such a shame that the lander component of Europa Clipper got cancelled.

It did?! :(.

Shame. We should be scrambling to land probes there yesterday.

Yep, yet another casualty of Congress's obsession with wasting money on SLS. Spending another $10B on an SLS upgrade that is still too rough of a ride for any payload is fine, but spending $1B on a lander is too much.

With Europa Clipper there was also the incident that Congress tried to write into law that it had to launch on SLS. The Clipper team were leaning towards using Falcon Heavy ($90M). In the end Congress only relented because the Clipper team said they'd need another $1B in funding (in addition to the $2B+ for an SLS launch itself) to make the delicate instruments on Clipper capable of withstanding the extremely rough ride that SLS offers.

So now Europa Clipper will be a Jupiter orbiter that does several flybys of Europa.

I'm ready for beach front property when Jupiter finally becomes the Sun's companion star to warm up Europa

Use them together. Use them in peace.

What is this quote from?

2010: Odyssey Two, Arthur C. Clarke's sequel to 2001: A Space Odyssey

Seems pretty. Will read soon.

The film version is flawed but still well-worth anyone’s time who got this deep in the thread & enjoys hard, near-future sci-fi.

My theory is that 2010: The Year We Make Contact is a lot like Blade Runner, pre- the various Ridley Scott re-cuts.

Drop the voiceover, tweak the ending to be less literal / sentimental, fix some of the FX matting, and you’d be left with one of the best serious SF films since 2001.

I enjoy both; 2010 is more an action piece wrapped with this period-specific visuals, coming also with burden of the real-world Cold War. While 2001 is a cinematic masterpiece that ended times of this naive pulp-scifi with its metal pointy rockets and damsel in distress tropes. The only thing I really really don't like the paint-psychodelic visual that Kubric used instead of Clarke's "Grand Central Station of the galaxy".

I really wish the remaining books would be turn into movies and so the Clarke-Baxter' A Time Odyssey series.

Surprised they haven't made 2061 with modern FX and budget so they can market it as a trilogy.

Must be too busy rebooting batman over and over for the 100th time I guess.

Came for this, was not disappointed.

[flagged]

An aside, but hovering over the image only to have it obscured... and then smaller on click, is a little comical.

I'm glad you posted this - I went back just to see this and gave an audible laugh. More than a little comical!

And then if you click on "Expand" (after clicking on the click which makes it smaller), it is restored to its original size.

We might have discovered carbon below 10km of ice on another celestial body, but we still cannot make sense of magic smoke.

This is obviously a ginormous leap from this announcement and just a tangent sparked by it. The possibility of intelligent life developing on a world like Europa encrusted with what is effectively a miles think solid atmosphere has always been one of my favorite feasible sci-fi hypotheticals. Could you imagine how that would impact their culture? Would they even know there is anything on the other side of the ice? Them finding out about us would be even more world shattering them us finding out about them.

The relevant sci-fi is the planet of Krikkit from the 3rd Hitch-Hikers book, Life, the Universe, and Everything. On that world, life evolved under a permanent blanket of cloud. At no point did they ever see the stars, or think that there might be something of interest above them. Until one day they sent up a rocket which penetrated the dust cloud, and for the first time they became aware of the rest of the universe.

Their response? “It’ll have to go.”

*Until one day a rocket crash landed on their planet (which caused them to create one in the first place)

[dead]

For comparison, the furthest we've dug down is about 8 miles, and Europa's ice crust is estimated to be 10-15 miles. So, yeah that would be like us getting discovered by mole people from nearly twice the depth we're capable of reaching. It's fun to think about what a civilization on Europa would think about their world. You can go up, but it gets colder and the pressure gets lower. It'd be like trying to go to space, but you have to dig to get there. Perhaps the change in density would make any such upward drilling unstable and beyond their means.

Oh this reminds me of Cixin Liu's (of the Three Body Problem fame) short scifi Mountain.

It describes an alien species that lives in the mantle of a planet. Their explorer finally dug through to the crust, when they were met with never before seen liquid water that instantly kills them as well as their (non water proof) equipments.

Fascinating short story.

No need to dig, you just melt yourself downwards. It's not exactly like digging through rocks on Earth.

Would liquid pool up as you melt the ice? I guess you'd need to pump it out. Is that even possible at that depth? The liquid might boil on the way up.

Your craft is denser than the liquid, so you just kinda drop through it and keep melting.

Doesn't the heat you have to produce increase as you go deeper?

In this case, the digging is from the perspective of a Europan living under the ice, and having to dig to go up.

Of course, barring collapse, the rocks won’t reform right above you as you go.

I wonder if one can apply some heat to the cable or wire dropping you down, and thus create a more open conduit.

What's the pressure like at that depth? That seems like it would have some implications to be dealt with

IIRC the pressure at the bottom of Europa's theorized ocean in similar to at the bottom of earth's ocean. The greater depth is compensated by the lower graviation field.

I don't want to spoil anything but intelligent life that evolves under high pressure depth is explored in Project Hail Mary by Any Weir (author of recent popular culture book then movie The Martian).

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

https://www.amazon.com/Project-Hail-Mary-Andy-Weir/dp/059313...

Thanks for the recommendation, seems excellent

Apparently the ring builders in The Expanse books were supposedly squids from an ice encrusted planet/moon.

It is an odd idea of how they’d even discover it. Assuming their natural habitat is a thermal vent on the ocean floor, they’d need pressure suits or probes to travel up to shell. Then they’d need to essentially create a Kola Superdeep Borehole in the sky, and there’s no obvious reason to do that, especially since drilling down into rock would be easier, and certainly more lucrative. (ie there aren’t any valuable materials in ice). This is assuming they don’t discover a 15 km deep fissure, which seems unlikely because I don’t think individual fissures discovered are that deep, all fissures are transitory, and probably randomly distributed. Sure a seismic network in the sky would could find evidence of fissures, but why are you building a seismic network in the sky?

It would be hard to tell if the rest of the universe even existed. No electromagnetic radiation or cosmic rays are going to make it through the ice. They'd have to get all the way to neutrino telescopes or gravity wave detectors to sense anything outside their ocean, and why would they spend the resources? Humanity could see our moon and it still took us thousands of years to get there.

Really they'd only do it if they managed indefinite population growth without poisoning their biosphere with waste products, and had to mine out the ice shell just for more living space. That would be tough: the equivalent would be if every square meter of the Earth's surface, including oceans, was as densely populated as Manhattan. That gets us up to 14 trillion people. Now make every building 10 km tall.

> there’s no obvious reason to do that

I think the reason would be that they’d realize they were in the middle layer of a multilayer ball.

My assumption is that at some point they would explore the entire ocean-floor habitat, discover the world is an oblique spheroid, and wonder what’s up. As soon as that happens the impetus becomes “obvious” and it’s a problem of technology.

Have you seen the movie Europa Report ^^ ?

Only a couple hundred more requirements that have to be exactly right for life to even exist there, but hey, this could possibly maybe be one...

I’m still looking for intelligent life on this planet!