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Colonizing the Outer Solar System
When I was a kid, I felt the most exciting thing to do with my life would be to colonize another planet.To answer your questions.
A. Absolutely doable, and the technical spin-offs and scientific discovery in materials, computing, medical and energy sciences and engineering disciplines would more than pay for the investment.
B. It would be exciting - plus see above spin-offs that would create another technical leap forward for human society.
C. There are no downsides. The downsides all occur from not doing it.
First off, thank you to you, Matthew, for starting this thread: you just made my day with a subject dear to my heart and which I have been studiing and researching for decades. On your questions:
A. Yes, it is absolutely doable. We can use technologies already developped in past decades (nuclear rockets) or recently (magneto-plasma engines) to send a ship to Jupiter and Saturn. One big condition: don't skimp on the budget (à la NASA) and make a ship big enough to accommodate large contra-rotating centrifuge carrousels, to provide artificial gravity to its crew for a return voyage that will last a few years. Also, give the ship adequate anti-radiation protection (especially in the crew areas).
B. Benefits would be many:
- Find second homes for Humanity for its long term survival. Many moons of Jupiter and Saturn harbor huge amounts of water ice, thus can provide the water and oxygen that will be vital to Human habitats, along with plenty of rocket fuel in the form of cryogenic oxygen and hydrogen.
- Titan, in the Saturn System, is a treasure trove of hydrocarbons and could fuel extensive chemical industries. Smaller, rocky moons and asteroids can provide other minerals and ores.
- Jupiter and Saturn themselves could be mined for their light gases (helium, hydrogen, methane, etc.).
- We could well find the first traces of alien lifeforms on the icy moons of Jupiter and Saturn. Europa, Ganymede, Callisto, Enceladus, Tethys, Dione, Rhea, Iapetus and Titan all could be harboring life.
- It would be the greatest adventure of Humanity's history.
C. Like Graeme said, I see no downside. Yes, many will whine about the huge costs of such a long-term project but, with such mentality, Columbus would not have discovered the Americas.
Let's not forget as well the immense mineral and ice resources found in the Asteroids Belt (including the dwarf planet Ceres). I could see a second Gold Rush develop in the Asteroids Belt in a century or so.
A. Yes, it is absolutely doable. We can use technologies already developped in past decades (nuclear rockets) or recently (magneto-plasma engines) to send a ship to Jupiter and Saturn. One big condition: don't skimp on the budget (à la NASA) and make a ship big enough to accommodate large contra-rotating centrifuge carrousels, to provide artificial gravity to its crew for a return voyage that will last a few years. Also, give the ship adequate anti-radiation protection (especially in the crew areas).
B. Benefits would be many:
- Find second homes for Humanity for its long term survival. Many moons of Jupiter and Saturn harbor huge amounts of water ice, thus can provide the water and oxygen that will be vital to Human habitats, along with plenty of rocket fuel in the form of cryogenic oxygen and hydrogen.
- Titan, in the Saturn System, is a treasure trove of hydrocarbons and could fuel extensive chemical industries. Smaller, rocky moons and asteroids can provide other minerals and ores.
- Jupiter and Saturn themselves could be mined for their light gases (helium, hydrogen, methane, etc.).
- We could well find the first traces of alien lifeforms on the icy moons of Jupiter and Saturn. Europa, Ganymede, Callisto, Enceladus, Tethys, Dione, Rhea, Iapetus and Titan all could be harboring life.
- It would be the greatest adventure of Humanity's history.
C. Like Graeme said, I see no downside. Yes, many will whine about the huge costs of such a long-term project but, with such mentality, Columbus would not have discovered the Americas.
Let's not forget as well the immense mineral and ice resources found in the Asteroids Belt (including the dwarf planet Ceres). I could see a second Gold Rush develop in the Asteroids Belt in a century or so.
Getting there will soon be doable, as Michel points out, with nuclear propulsion. However, I disagree that colonization is likely. The big problem is you have to take just about everything with you, because there is no chance of finding ores. Once you get to the Jovian system, everything is at least 50% ice, and since much will have sunk to a core, the outer parts will be largely ice. No ores, the rocks are mainly ice, and assuming you want some sort of power plant, you have a problem with waste heat - you will slowly melt the ice underneath your power plant and it will sink into the ice. Oops.I also disagree that the outer asteroid are useful. Again, no ores because no geochemical processing. Some of the very inner asteroids do have iron cores, but otherwise you are mining basalt. There is plenty of basalt on Earth that is a lot easier to process.
As an aside there will be no life on the Jovian moons - there is a clear shortage of nitrogen and carbon
Ian, there are plenty of high-level scientists that would disagree with your assessment about the chances to find life on the moons of Jupiter and Saturn. To quote you: 'there will be no life on the Jovian moons'. What makes you so categorical on that subject and why should'nt we believe the contrary opinions from other scientists?
Michel, if you look at the atmosphere of Europa, such as it is, and it is thinner than only the very best vacuum pumps on Earth can make, the main "gas" is hydroxyl radicals! About five orders of magnitude less is sodium in the gas phase! There is no nitrogen to be seen, and that runs across the Jovian system. There are very small amounts of carbon dioxide in the slightly thicker atmosphere of Callisto, and that is presumably due to the oxidation of carbonaceous stuff from the odd chondrite that has landed from space. So the reason there will be no life is the materials necessary for life simply are not there.There is another more subtle reason - there is no mechanism for making phosphate esters that we know of that could operate under the ice at Europa (or any other Jovian moon). The only mechanism we know of requires photons, and that means it has to happen at the surface. The reason is, you have to pump quite a bit of energy into the system, and NOT to water, which breaks down phosphate esters. As an aside, at the recent conference a means of polymerising adenosine and uridine phosphates to make RNA polymers was presented - this involved repeated wetting and drying. It may not be the only method, and again, I suspect photons would do it, as the problem is to get energy into the phosphate entity.
The Moons of Saturn do have nitrogen. There is no show for most of them, but I suppose the question of Titan is less clear. In my opinion, it is unlikely because for reproduction you have to separate polymer strands so they can be copied, and you need a solvent such as water or ammonia water, which is liquid down to about - 80 degrees C, and maybe a little colder with extra components added. It think Titan is still too cold for that, but I suppose there might be slightly warmer spots. Liquid hydrocarbons are useless for this. The second law of thermodynamics works against any solvent other than water or ammonia, and ammonia will always dissolve water.
One thing you notice in solar system science is that it is full of enthusiastic physicists and geologists. Chemists are far rarer, and biochemists are only a little more probable than hen's teeth. Enthusiasm is needed, of course, to get funding, and space probes need a lot of it. By the way, I am not criticising space funding so far, but I really believe digging into Europa hoping to find life is an exercise doomed to fail.
Graeme wrote: "When I was a kid, I felt the most exciting thing to do with my life would be to colonize another planet.To answer your questions.
A. Absolutely doable, and the technical spin-offs and scientific..."
Thank you Graeme for coming in hot with a totally positive take! I hear the opposite so often, it makes me want to give someone a boot to the head!
"LV 426 ... it's a rock. We never found any life there..."
Just want to add some material to the discussion. In his book Entering Space: Creating a Spacefaring Civilization, Robert Zubrin - the same scientist who wrote The Case for Mars - claimed that Saturn, Uranus and Neptune were "the Persian Gulf of the Solar System". Basically, these systems have an abundance of volatiles, deuterium and helium-3 to drive a fusion economy. Basically, colonies in any of these system (Saturn would be the best since its closest and has low radiation) would be able to provide enough fuel to last humanity for generations. It would also provide all the necessary methane and ammonia ices to help terraform Mars.
Yeah - the point of mining the solar system is not so much about bring stuff back to earth but to access resources for a solar system wide civilization.
Ian wrote: "Getting there will soon be doable, as Michel points out, with nuclear propulsion. However, I disagree that colonization is likely. The big problem is you have to take just about everything with you..."What about the Greeks and Trojans? They are certainly rich in minerals, as are the many, MANY smaller moons of Jupiter in its retrograde and prograde orbital groups and the debris disk. Sure, they are largely ice, but they would be much easier to mine, given their sizes.
Plus, you've got the asteroid belt in your rearview, which would provide an endless supply of minerals. So you don't really need to take it all with you, just source it semi-locally.
As for "there will be no life on the Jovian moons - there is a clear shortage of nitrogen and carbon". What are you basing that on? My understanding was that Europa had abundant carbon and nitrogen, and Ganymede carbon and other compounds (like amoonia), which was what allowed for their colored-band appearances. Also, those sounds like betting words! Care to put your money where your mouth is? :D
Graeme wrote: "Yeah - the point of mining the solar system is not so much about bring stuff back to earth but to access resources for a solar system wide civilization."Bingo! It's call in-situ resource utilization (ISRU). You harvest local resources, you use them to build local infrastructure and see to your needs, and then you worry about building an economy, complete with exports.
Last thing you want to do is drag stuff up a gravity well.
Graeme wrote: "Last thing you want to do is drag stuff up a gravity well."Not unless you absolutely have to. And of course, the moons of Jupiter/Uranus have a much lower escape velocity than Earth or any of the planets. So it would be the most economical case of firing stuff into orbit, assuming you had to.
Thank you for the positive inputs, Graeme and Matthew. Space certainly won't be conquered if we never try.
Matthew, regarding nitrogen in Europa's atmosphere, "Cassidy, T. A., Johnson, R. E., Tucker, O.J. 2009. Trace constituents of Europa's atmosphere. Icarus 201: 182-190." The coloured bits on Europa, etc, are most likely to be due to ferric oxide, from ferrous reacting with the hydroxyl radicals known to be generated.The rocky bodies in the solar system are essentially just that - rock. Basalt. Any metals in them will be in the form of silicates, and with no geochemical processing, will be in the relative concentrations as found in the disk material, less the gases. How do you intend to separate metals from silicates? For every kilogram of rock, half it is silica, a very large amount is magnesium oxide, iron oxide comes in at about 6% and everything else is minute. How do you tear all those silicates to bits? I have outlined one method that would work in space in my SF novels, but it depends on having a dedicated fusion reactor.
By the way, I want to encourage space exploration. What I said was you will not form settlements in the outer solar system, but yes, I guess you could try collecting gas from the atmospheres. I also do not think there is life in the outer solar system for reasons to do with reproduction, that I am covering in my blog posts.
Ian wrote: "Matthew, regarding nitrogen in Europa's atmosphere, "Cassidy, T. A., Johnson, R. E., Tucker, O.J. 2009. Trace constituents of Europa's atmosphere. Icarus 201: 182-190." The coloured bits on Europa,..."Atmosphere? Europa's life is believed to be within it's interior. It's a well-known fact that its tenuous atmosphere is composed of oxygen created by chemical disassociation. And to quote mutiple studies, the colored bands on Europa's surface are due to tholins, which suggest the presence of carbon, nitrogen and water.
http://adsabs.harvard.edu/abs/2017AAS...|
https://www.jpl.nasa.gov/news/news.ph...
http://adsabs.harvard.edu/abs/2002JGR...
Second, the asteroids in the Solar System may be mainly silicate material, but so are the terrestrial planets. There are countless methods already under consideration for extracting the precious metals they contain and even conservative estimates indicate that are megatons of gold, iridium, silver, osmium, palladium, platinum, rhenium, rhodium, ruthenium and tungsten for transport back to Earth; iron, cobalt, manganese, molybdenum, nickel, aluminium, and titanium available in just Near-Earth Asteroids alone.As for the possibility of life, it seems like you are taking a position of opinion. Are you keeping up with the current research on data regarding recent surveys of Europa, Ganymede, Titan and Enceladus? Already, complex organic molecules have been detected in the plumes of the latter moon, which was the first case of of complex molecules ever being discovered beyond Earth.
Matthew, I am not going to answer the issue of life - I am writing a series of blogs which are relayed to Goodreads, and I would prefer to leave this discussion until I have had a chance to state what I think. Unfortunately, the issue is a little complicated. Feel free to raise this again when I have finished.Regarding Europa, given that the interior liquids emerge to the surface from time to time, why would nitrogen not enter the atmosphere. N2 is a really energetically favoured form for the nitrogen element. Note the atmosphere of Titan. Finally, why would the reddish-brown colour not be ferric?
Re Europa, your first reference states "NASA’s planned Europa Flyby Mission will try to assess the habitability of Jupiter’s moon, Europa." Planned mission is not evidence of what they will find. They have yet to find it. The second reference states they plan to search some time in the 2020s . Your third reference states experiments of "hypervelocity impacts into ice with small iron projectiles ". Sorry, but that is not an analysis. Maybe you are right, but the current evidence, which you have ignored when I give a reference, is that there is no appreciable levels of nitrogen there. Matthew, if I give reference, I do not expect it to be ignored and replaced with three references that do not actually provide any evidence pertinent to the discussion. That they might some time in the 2020s is possible, but that would mean that it contradicts what we know now, so the odds are that it won't.
Yes, each body is basically silicate, BUT Earth has had 4 Gy of geochemical processing thanks to plate tectonics moving things around and sending water through much of the rock. Asteroids have had no such processing. The Moon has had fractional crystallisation, and may well be a good source or rare earth elements. Asteroids by and large have not melted because they were not big enough, although Vest and Magnya have, and maybe Eunomia. There are probably some asteroids that formed interior to Earth that have iron/nickel cores, and I agree they would be valuable assets, especially if we wanted to build space stations because the materials are already our of any gravitational well.
Since people know how to survive in the outer space - as they do on international space station, it seems anchoring a habitat to planets and similar celestial bodies is already a possibility. Hopefully, once nuclear transmutation becomes more accessible, it shouldn't become less of a problem to convert outside matter to what is needed for a habitat, so that supplies and resupplies won't be necessary
One of the problems indicated by this discussion is the difficulty that is becoming apparent for some with analysing evidence. Thus we have the statements:Europa has red streaks
Europa is a planetary body.
Some planetary bodies have tholins
Tholins are red
Therefore Europa has tholins.
I have put that in the form recommended by Aristotle, almost 2.5 kY ago, who made a big effort to get logical thinking accepted generally. He was not successful, and it appears he still is not. The problem is the statements are about a set of red objects, but they are one-way. If it has tholins, it is red, but if it is red it does not have to have tholins. As an example, Mars is red, because of iron III oxide.
It appears too many prefer to see what emotionally they want to see, what looks comfortable and exciting. Proper analysis appears to be merely a wet blanket for most. Which is probably why my fiction is down in the not very well selling league, because one of my themes is to have MCs that prevail by thinking properly.
Ian, you just basically said that others contributing to this thread are not thinking properly and can't analyze facts correctly. That, at least for me, is my feeling about your way of pushing your opinions in this thread.
Michel, any opinion must be consistent with the facts. If you find any of my facts to be erroneous, please point them out. I give a reference to a scientific paper that shows there is no nitrogen worth seeing on Europa, and get back because it has red streaks there must be thorns therefore there must be nitrogen. I hear people say there will be mining of asteroids, etc. Any planetary body starts with the dust from the accretion disk, and ends up as a solid mix. Unless there is some processing, which has occurred for iron-filled asteroids, it will have the composition of the dust. That is effectively similar to basalt. If you don't like those facts, show where they are wrong. You can feel they ought to be different, but that does not make it so. Nobody is going to mine anything unless they can get something of value out of it. At least not for long. If you think there has been some sort of processing concentrate certain elements, give us a clue as to what it was. You might be right. I am just going by what is known now.Just to be clear about terms, I am considering colonising to mean people go there and live their lives, bring up families, etc. If you just mean go out there and look for resources, do a "tour of duty" then come back, fine.
Ian wrote: "One of the problems indicated by this discussion is the difficulty that is becoming apparent for some with analysing evidence. Thus we have the statements:Europa has red streaks
Europa is a planet..."
That is not at all what I said, Ian. I said that Europa's banded appearance is believed to be the result of tholins, which are indicative of chemicals like nitrogen, oxygen and water.
As for your question about Europa, the interior liquids take millions of years to reach the surface. If nitrogen is part of the ice being churned up, then it would be present in the bands I already mentioned. The evidence of plume activity is another matter, but we have yet to even examine it. So saying that it should have nitrogen in its atmosphere if it's coming from within.
//Finally, why would the reddish-brown colour not be ferric?//
Why would objects in the outer Solar System not be ferric in nature? They too are red, but in those cases, it has been shown to be the result of methane being exposed to UV radiation. Hence why some scientists think the same pattern is at work here. Assuming it would be ferric merely because Martian soil is seems about as un-analytical as anything you've criticized.
As for the sources, did you read past the titles or abstracts? It is these studies that assessed the composition of Europa's surface, based on past missions, and ventured the chemical elements are there necessary for life. I hardly ignored what you gave, I offered counter-arguments. I assume we're allowed to do that here.
On the last point, I will concede much of what you've said, but the evidence for asteroids with iron cores is the Main Belt is quite promising. These may have very well formed within the interiors of larger bodies - in fact, we know that this is what became of Psyche - and the metals they offer would be immensely abundant.
Michel wrote: "Ian, you just basically said that others contributing to this thread are not thinking properly and can't analyze facts correctly. That, at least for me, is my feeling about your way of pushing your..."He does tend to do that, doesn't he? A reminder to Ian, you may be an accomplished chemist, but that doesn't lend your opinions more weight than others on matters of astronomy, especially when people have taken the time to familiarize themselves with the latest research and exploration news.
Hi Guys, scientific questions will be amenable to physical evidence. Are we sure we are discussing the same specific topic, if so then there should be a set of available physical evidence that will allow us to come to a definitive conclusion.Noting the conclusion may be that we are "not a 100% sure..."
This is also not an area of expertise for me, so I'm not weighing in. There are others who are far better informed than I am.
Matthew, the basic state of iron in rocky objects is ferrous, as in the olivine and pyroxene structures. In the original disk, a lot was simply iron. I would expect if the ice broke on Europa and water bubbled to the surface, it would be dirty, and hence contain ferrous. Hydroxyl radicals, known to be there due to the photolysis of water, will promptly covert ferrous to ferric, or even higher oxidation states. That is what has happened on Mars to surface dirt. If you scrape off the top few inches the ground is grey. The issue here, Matthew, is NOT astronomy - it is chemistry. Similarly, tholins are not the major degradation product from the photolysis of nitrogenous material - N2 is. You might care to look at the atmosphere of Titan, which is about 98% N2. There are tholins there, but nowhere near as much as N2, and most of the carbon seems to have formed hydrocarbons. Those chemical ratios will be the same for all other bodies, but if you look at the Kuiper Belt objects that are reddish, assumed due to thorns, they have too weak a gravitational field to hold nitrogen. The Jovian satellites are big enough, so I would expect some N2 if Europa, Ganymede or Callisto had nitrogen. They do not have it.Out may take millions of years for liquids to reach the surface. The solar system is 4.5 Gy old - easily enough time, AND Titan got its atmosphere fro the interior. We know it did not come from space because there is a very severe shortage of 36Ar.
I read your links and posted my objections to them. You have ignored my objections.
Re asteroids, there are some in the main belt that appear to have iron cores. Many do not, but I think the best chance of mining asteroids is to go for the Aten or Atira asteroids. Some of them will be objects removed from the main belt, but even if they are, they are a lot closer, so a lot easier to get at. My personal OPINION is that some of them will have iron cores because they did not originate in the main belt, but are objects formed originally, and were never accreted. Such bodies could be the origin of enstatite chondrites, which are quite different from chondrites from the main belt, and have oxygen isotopes very similar to Earth. Closer, and in my opinion, more desirable.
Ian wrote: "Matthew, the basic state of iron in rocky objects is ferrous, as in the olivine and pyroxene structures. In the original disk, a lot was simply iron. I would expect if the ice broke on Europa and w..."That's entirely possible, in fact, I was just thinking the same - how iron would rise up from the core-mantle boundary and become part of the ice. But its one of many possibilities. Tholins are no less of a possibility because we know with confidence that Europa has organic molecules in its interior which would become exposed to ultraviolet rays once exchanges take place.
And yes, chemistry is central to this, but the point I am making is that I and others are hardly uninformed on the subject. This is what I do for a living, thank you very much. So please don't talk to me as if I'm some kind of novice or don't know the basics of the Jovians or Cronians (i.e. you've mentioned Titan several times, I am well-versed in its atmospheric composition, prebiotic environment and organic chemistry).
And no, I haven't "ignored" your objections, I've responded to them by showing that your objections do not represent any scientific consensus. You've repeated your objections to the idea of asteroid mining and finding life on Europa many times over and I am continuing to respond to them. Don't mistake disagreement for dismissal. In this as with other subjects, I feel you are taking a narrow view based on entirely your own work.
As for asteroids, there appears to be some agreement there. Asteroid mining would be a possibility, even if it would be more difficult and less lucrative than some suspect.
Graeme wrote: "Hi Guys, scientific questions will be amenable to physical evidence. Are we sure we are discussing the same specific topic, if so then there should be a set of available physical evidence that will..."I would like to address something Ian raised, which was that "you want some sort of power plant, you have a problem with waste heat - you will slowly melt the ice underneath your power plant and it will sink into the ice. Oops."
This problem is easily addressed. For one, it would seem to me that you wouldn't want to build power plants directly into the ice. The smart money would be to build inside craters, insulate the surface with spray rock, and build your power plants (which would presumably rely on solar power and/or fusion) in a such a way that waste heat is dissipated to heat the colony.
It seems obvious to me, mainly because no engineer would be stupid enough to do otherwise.
Also, Ian, these and other statements strike me as classical academic elitism://One thing you notice in solar system science is that it is full of enthusiastic physicists and geologists. Chemists are far rarer, and biochemists are only a little more probable than hen's teeth. Enthusiasm is needed, of course, to get funding, and space probes need a lot of it. By the way, I am not criticising space funding so far, but I really believe digging into Europa hoping to find life is an exercise doomed to fail. //
//It appears too many prefer to see what emotionally they want to see, what looks comfortable and exciting. Proper analysis appears to be merely a wet blanket for most. Which is probably why my fiction is down in the not very well selling league, because one of my themes is to have MCs that prevail by thinking properly.//
To claim that NASA, the ESA and every other federal space agency is being deliberately emotional in their thinking when evaluating missions and exploration simply to get funding, or that you are somehow more qualified, also strikes me as conspiratorial. Not only do they have countless scientific minds from all backgrounds at their disposal evaluating their missions, their research and information is current.
Also, claiming your book sales are an indication that no one wants to hear the truth, that's just self-indulgent. You may have your opinions, and no one would doubt that they are informed, but you are not the only clear-thinking person in the room or more qualified than the people currently in charge of the world's space programs.
Matthew, obviously building power plants on rocky bodies would be sensible, but the problem is that the Jovian satelites (other than Io) have relative densities less than 2, which means they are more than 50% ice. Now to form a rocky mass, the silicates have to melt, which requires temperatures over 1000 degrees C. If so, they would melt the ice under them and sink. We know that each of these satellites partially differentiated, so any mass of significantly greater density would sink. Accordingly, the surface is almost certainly dirty ice, i.e. ice with the original dispersion of dust in it. There should not be any rocky masses, or there have been a lot of faulty observations.
While I am not what you would call a qualified scientist, I will say this: the only data and info we have on Jupiter, Saturn and their moons come either from distant observation by telescopes or by stand-off measurements by passing probes. Nobody has yet landed on these moons. Nobody has drilled the surface of these moons for samples. So I find it ludicrous that anyone would have categoric opinions about the presence or not of life (in any form) under the surface crust of these moons. The same goes for the composition of asteroids in the various asteroid belts in the Solar System. The fact is that we still have very few hard facts about these moons and what we will find on or inside them. What we know for sure is that many of these moons contains lots of water ice. With that water ice, we can get oxygen to breathe and water to drink. With water, we can also operate hydroponic gardens to feed colonists, at the price of having to either import or find somewhere in the Jovian/Saturn system the necessary fertilizing elements (we could provide some of these ourselves, via our urine and feces). So, I choose to be optimistic about the future prospects of colonizing the Outer Solar System, including the Main Asteroid Belt and asteroid groups, rather than making categoric statements to poo-poo the idea based only on a partial knowledge of the facts on the ground. Let's keep our minds open and our hopes and dreams up!
Ian wrote: "Matthew, obviously building power plants on rocky bodies would be sensible, but the problem is that the Jovian satelites (other than Io) have relative densities less than 2, which means they are mo..."Hence why I recommend placing down spray-rock. It's a speculative idea at this point, but it involves materials that are liquid at cold temperatures and harden at much lower temperatures. And if you were to take the realistic approach and place silicates on top of ice, you could create your own craters. Let the silicate material harden on top of the ice to form the ground layer of a colony, lay more on top to level it off, and then build your power plants.
Matthew, we do not know Europa has organic molecules in its interior because apart from its gravitational effects, and what we can infer from the surface, we know nothing about the interior. All we have is satellite data about the surface. I am glad to hear you are proficient in chemistry. Please explain then how you can get nitrogenous material on the surface without getting any in the atmosphere when the gravity is strong enough to hold it and nitrogen molecules are in possibly the deepest potential well of any molecule, and why the albedos of Europa and other Jovian moons is over an order of magnitude greater than tholin covered bodies?
As to why there is no nitrogen in the Jovian system and there is in the Cronian system, I have offered an explanation in the latest blog that is on Goodreads. Feel free to comment, explaining any of the chemical errors. Note also that Cronian system does not appear to have prodigious tholins on their surfaces.
Ian wrote: "Matthew, we do not know Europa has organic molecules in its interior because apart from its gravitational effects, and what we can infer from the surface, we know nothing about the interior. All we..."
That is exactly the point I just made in my post #33, Ian, yet you insist again on pushing you knowledge as a chemist to justify rejecting others' opinions and also to make sarcastic remarks about other people's knowledge of chemistry. Please get off your high horse and realize that this is a group discussion, not a one-sided lecture by you.
That is exactly the point I just made in my post #33, Ian, yet you insist again on pushing you knowledge as a chemist to justify rejecting others' opinions and also to make sarcastic remarks about other people's knowledge of chemistry. Please get off your high horse and realize that this is a group discussion, not a one-sided lecture by you.
Ian wrote: "Matthew, we do not know Europa has organic molecules in its interior because apart from its gravitational effects, and what we can infer from the surface, we know nothing about the interior. All we..."Once again, you are telling me nothing I don't already know. I said it is believed that there are organic chemistry taking place inside Europa because the constituent elements all appear to be there, based on survey data (or at least, there is compelling evidence of such). Also, there's plenty of nitrogen in Jupiter's atmosphere, so unless its moons were all acquired (no evidence of that), they too had access to this element.
And I never said I was proficient in chemistry, nor implied I was, so let's not get arrogant. However, there is no basis for saying there's no nitrogen in Europa's atmosphere or the Jovian system! It may be tenuous, but I've already shown you research that claims it is likely to be there, which you've denied. And the reason for the differences in albedo is obvious, the concentrations of organic molecules (such as methane) are higher in the outer atmosphere, where the greater distance ensures they remain in ice form.
You're stating opinion here and asserting a singular claim to authority to back it up, and we both know that this isn't the first time. You've also asserted your unique qualifications as a chemist to dispute the widely-held Nebular Theory, and I recall the argument going the same way. I am going to move this topic forward now, with or without your participation.
To add a little good faith to this discussion, let us assume that the Jovian system is bereft of life. That is secondary to our discussion at any rate, and would actually make colonization an easier affair. If there is no native life to worry about, then the ethical concerns about interfering or eradicating indigenous life is no longer an issue.That being said, what do you imagine colonies on Jupiter's moons would be like? Where would you want to set up shop (only three real options, unless you're really adventurous and have highly-advanced technology). And how would the colonists see to their needs.
Shameless plug, I did an article on this for UT. Please feel NO obligation whatsoever to check it out. I just mention it because it's there.
https://www.universetoday.com/130637/...
And here's a great video from our friend, with whom my does does the occasional collaboration, Isaac Arthur:
https://www.youtube.com/watch?time_co...
And on the subject (just broke), the argument over whether or not Europa is habitable is likely to be settled sooner other than later:https://www.jpl.nasa.gov/news/news.ph...
Matthew, the reason I said you were claimed proficiency came form this quote from your post: "And yes, chemistry is central to this, but the point I am making is that I and others are hardly uninformed on the subject. This is what I do for a living, thank you very much. "I you do it for a living, I assumed you were proficient. Sorry if I got this wrong.
There will be no ices in Europa's "atmosphere" - they haven't been detected and the atmosphere is so thin they could not be supported.
I don't know what you mean by my rejecting the "nebular theory" - for what it is worth, everyone accepts planets formed in an accretion disk because you can see it happening. However, the oligarchic formation of planets requires planetesimals, and after 70 years, nobody has a realistic means of how they form, and the idea that dust coagulates is wrong because we see dust in all the disks, except sometimes in specific zones.
The reason Jupiter's atmosphere has nitrogen is because the atmosphere was retained as gas from the accretion disk and is essentially of solar composition (except the hydrogen and helium are actually relatively depleted.)
Michel, I have no intention of giving a lecture, and I apologise if anyone thinks I am, but a discussion should be based on facts, not what you hope are facts.
Matthew, I read your "shameless plug", and by and large, I think it is a fairly good article. Obviously I disagree about the nitrogenous material under the ices, however, in my opinion, the article makes the strongest case yet for why the satellites of Jupiter, except possibly Callisto, won't be colonised - the radiation levels are just too high. Robotic missions to the inner moons would seem to be all that is likely to happen.
After a little more thought, I guess I should be strongly advocating such missions to Europa. Since everyone is so sure there will be lots of nitrogenous stuff under the ice on Europa I should be pleased to have the chance to prove them wrong. My problem here is if they don't find anything they will say they didn't dig deeply enough. (In a recent post on SpaceCom they are suggesting even a centimeter down could be sufficient!)Being a little selfish, perhaps, I would rather they go and dig deep on Mars because there the find should be positive for solid nitrogenous stuff (if I am right and they dig in a suitable place, suitable being where water once lay). As far as Europa goes, by the time that is settled one way or the other, I shall probably be dead, so younger people here could recall this post and see what the answer to this issue was.
Congratulation, Ian: you basically chased away the other participants to this thread with your tone and vehemence. This was supposed to be a discussion about the future colonization of the Outer Solar System, but you turned it into a diatribe to show your expertise in chemistry. You are now free to talk with yourself.
It was my intention to provide information others probably do not have, and it was most certainly not my intention to chase anyone away. Accordingly, unless requested, I promise not to post anything further in this discussion. Everyone else is free to say whatever they want. Please go for it - say whatever you want.
Ian wrote: "It was my intention to provide information others probably do not have, and it was most certainly not my intention to chase anyone away. Accordingly, unless requested, I promise not to post anythin..."Ian, we understand you didn't want to alienate others, but you committed the cardinal sin. You posted opinion as unassailable fact and even said as much - that NASA doesn't know what it's doing because it lacks people of your background and are lying for the sake budgets, and that you're truth-saying nature is why people aren't buying your books.
You are free to post things and offer opinions, I'm sure they would be welcome. Just please don't act like you're word as a chemist is the final authority on the subject.
Getting back to the subject at hand, let's consider life on the Jovian moons first. As I said earlier, you've only got three options unless you are REALLY willing to get creative - Europa, Ganymede and Callisto. In the first two cases, you've got Jupiter's radiation to deal with, though Ganymede provides some protection due to its magnetic field. 
Callisto is beyond the reach of Jupiter's powerful magnetic field, but its arguably way less interesting. It's interior ocean is cold and not likely to support any life. But lots of craters to play in! And if you're adventurous, Io has lots of lava plumes and sulfuric chemicals (if you're into that kind of thing).
What are the best options from a colonisation perspective?
Locations that is in priority order with rationale.Would we go back to the moon first establish a base there to prove technology or is going straight to Mars a better option.
After Mars, what then?
Graeme wrote: "Locations that is in priority order with rationale.Would we go back to the moon first establish a base there to prove technology or is going straight to Mars a better option.
After Mars, what then?"
Whoa, slow down. Okay, so establishing an outpost on the Moon (and in orbit of the Moon) is the best option before moving onto Mars. Then you want an outpost on the Martian surface and a habitat in orbit. From there, you get your ass to the Asteroid Belt, build some bases on the larger rocks (Ceres, Vesta, Pallas and Juno) and then onto Callisto. As the outermost moon in the Jovian system, its the natural first stop.
Funny thing is, people who claim "we need to go back to the Moon first before going to Mars" - i.e. Obama was wrong and Bush/Trump are right - don't seem to know the first thing about the "Journey to Mars" (approved in 2010 by the Obama admin). NASA's plan has always involved operations in cislunar space before moving onto Mars, the establishment of a habitat orbiting the Moon (the Deep Space Gateway), collaborating with the ESA to build a Lunar Village, and the creation of a Mars Base Camp in orbit around Mars before any missions to the surface take place.
Step by step, it's the only way.
I myself am for going directly to Mars from Earth orbit, where the Mars ship would be assembled before departing for the Red Planet. I feel that a combination of nuclear rocket engines and magneto-plasma engines (two technologies we already know) would be efficient and powerful enough to make the intermediate step of a Moon base or orbital station unnecessary. I also favor sending a big ship, loaded with a number of landers loaded with the prefabricated elements of a Mars surface base, which would ideally be built inside an empty lava tube or cavern in order to avoid the strong radiations bathing the surface of Mars. One a Mars base is solidly established, switch your efforts to going to the Jupiter and Saturn systems and build outposts there, sunken under the surface of water ice of a moon in order to protect the astronauts from Jupiter's radiations. From there, things will pick up, but it will take many decades and maybe up to 200 more years before Humans are solidly established throughout the Outer Solar System. However, I believe that it will be done.
Michel wrote: "I myself am for going directly to Mars from Earth orbit, where the Mars ship would be assembled before departing for the Red Planet. I feel that a combination of nuclear rocket engines and magneto-..."Hi Michel, are these the technologies that you are discussing?
REF: WIKI:
https://en.wikipedia.org/wiki/Variabl...
https://en.wikipedia.org/wiki/Nuclear...
World, Writing, Wealth
Books mentioned in this topic
Entering Space: Creating a Spacefaring Civilization (other topics)The Case for Mars (other topics)
A. Do you think its doable (allowing for time and technological advancements)?
B. What would be the benefits?
C. What would be the downsides?