Plutoids and Rogue Planets, Titanformation process, a cold treasure?

Void · 2016-10-21 09:12:56

6/11/2024, altered title to "Plutoids and Rogue Planets, Titanformation process, a cold treasure?" by adding "and Rogue Planets".

Antius caused me to do this.
http://newmars.com/forums/viewtopic.php?id=358
From that thread Antius said:

Antius
Member
Re: Titan Terraformation - Is it possible?
You don't need to turn Rhea into a star. Fusion reactors could simply be hung from balloons in Titan's atmosphere. That way 100% of the heat produced goes into the atmosphere. And you can cool the reactors by convection, which means better power density and better economics.
Still the wrong philosophy in my opinion. Titan is not Earth and is fundamentally different to the Earth in ways that cannot be reconciled with an Earth like environment. It is a ball of ice, ten times further from the sun than the Earth is. Its surface is cryogenic. Attempting to turn it into an Earth-like place using classic terraforming would require enormous energy and resources and you rapidly end up talking in terms of ridiculous levels of planetary engineering trying to build an Earthly environment: artificial stars, artificial surface, giant heat pumps to prevent the ice from melting, etc.
Instead, you could simply accept the place for what it basically is, and turn its attributes to your advantage. It has 1bar surface pressure, so habitats do not need pressure shells. Its atmosphere is cold and dense, so buoyant lift is easy. It has seas of liquid methane, probably the best heat sinks in the solar system. The last attribute means that habitats can be volumetric, you can put many layers of habitable land into a single habitat. In free space or on worlds without atmosphere, this is extremely difficult to achieve because of the amount of heat that needs to be removed from volumetric habitats. On Titan, liquid methane provides an excellent heat sink that can simply be pumped through heat exchangers and boiled off. You could conceivably create huge amounts of land this way. Solid ice can be used as the construction material for the outer shell. It can be melted and cast into the shapes we need. A habitat could start as an inflatable double walled polyethylene sphere. Fill the double wall with warm water heated to melting point using a nuclear power source and voila, you have very cheaply provided a habitable volume. Heat losses to the Titan atmosphere will prevent it from melting. Divide it into decks 10m apart, and a 1km diameter ice shell will support 52km2 of internal land. Enough for a city of millions of people, trees, lakes, whatever you want.
Global warming of Titan would eventually become an unwanted outcome, since temperature rises would compromise the great natural advantages that the place has to offer.

Plutoids:
https://en.wikipedia.org/wiki/Plutoid

So, the treasure would be having worlds that can hold an approximately 1 bar atmosphere preferably Nitrogen dominated, and that such worlds would serve as radiators of heat. This notion becomes much more sensible, if artificial fusion power becomes a reality.

I am guessing that smaller plutoids will underperform, as far as retaining such an atmosphere.

I choose to consider Triton to be a plutoid as well, or at least it seems likely that it was born as one.
It certainly resembles one.

I am guessing that from time to time plutoids get struck by a large impacting object, and that their atmospheres then inflate temporarily, and so during those times they might resemble Titan for a while. Of course, I am talking about diverting close passing comets, to impact a plutoid for our purposes, not waiting around for such an event to happen naturally.

So, that could be an initiating process, and then Fusion would be a holding process.

Where Titan has liquid Methane, perhaps these worlds could as well, but could they perhaps alternately have liquid Nitrogen, to fulfill the desire provide cryogenic cooling of multilayered very large building habitats?

So, supposing that fusion power becomes real, then that is like a hot summer day that will never end, as far as the human race is concerned, so maybe you do want ice cream. Maybe Plutoids?

I'm done for now.

Last edited by Void (2024-06-11 21:23:56)

Antius · 2016-10-21 15:48:41

I think Titan may be a special case. Its escape velocity is 2.3 times greater than Pluto. Even at Titan temperatures, Pluto would lose atmosphere quite rapidly. I do not know what the half life of a 1 bar atmosphere would be, but to produce a 1 bar surface pressure, the column density would need to be ~20x greater than Earths. At such reduced gravity, the scale height would be many times greater than Earth's and the atmosphere would extend a long way out into space. The higher you go, the lower the local escape velocity and Pluto's surface Ve is only 1200m/s.

Thats not to say that Plutoids wouldn't have their own advantages. The abundance of nitrogen ice would provide an excellent heat sink. And any atmospheric pressure at all reduces the difficulty of building a habitat. If a body is dominated by water ice, then habitats could be constructed within ice covered lakes. An atmospheric pressure of 1KPa would be sufficient to suppress evaporation at 0C. Under Pluto gravity, 160m of water would produce a 1bar pressure. Under Sedna gravity, roughly twice that depth would be needed. Pluto may be problematic as its entire crust is dominated by frozen nitrogen, although there are sizable inclusions of water ice floating on the nitrogen crust.

Last edited by Antius (2016-10-21 16:18:22)

Terraformer · 2016-10-21 16:15:58

Part of the problem with building habitats on plutoids is that they're likely to be covered in nitrogen ice. That's not a stable base for a colony, given the waste heat, so you're going to want to sublimate your way down to the water ice at least.

I don't think retaining an atmosphere will be that much of a problem, though, given how cold it would be, the weak solar wind, and the lack of UV affecting the exosphere. The dominant escape method would be thermal. The average velocity of gas molecules is given by sqrt(3RT/m), so assuming a nitrogen atmosphere with an exosphere temperature of 63K - which doesn't strike me as being unreasonable - the average speed of molecules in the exosphere will be ~240 m/s. If the body has an escape velocity comparable to that of Ceres (500 m/s), it's quite plausible that the atmosphere could remain for tens of millions of years, due to the low density of the exosphere - loss from the exosphere would be quite rapid, but it's a very small proportion of the overall atmosphere.

The lower temperature also means the atmosphere would be much denser. Titan's is, I think, 4.5x as dense as Terra's, and if the temperature was even lower... that would significantly reduce the scale height.

I'm a big fan of Titanforming, followed by paraterraforming of the surface. It's going to need some very good aerogel insulation of course, and probably proton-proton fusion.

Antius · 2016-10-21 18:30:26

Maybe Charon would be a good target for colonisation. Its surface is largely water ice. Its gravity is about 40% of Pluto's and a 400m depth beneath its surface is equivalent to a pressure of 1 bar. There are extensice ammonia hydates on its surface, which would be useful fertliser for aquatic plants in an ice covered lake. On the downside, there appears to be little else on this moon that man might use.

Pluto's smaller moons are all water ice rich and would therefore also be good candidates for aquatic terraforming.

Void · 2016-10-21 19:28:35

Well...

That's a great pity. I guess I will have to fall on my sword for today. Tomorrow is another day. Still it is good to know better what the limits are.

For now, even beyond the Ice giants, in my mind, the Plutoids are the least desirable real estate.

Earth of course is the best.
Mars, is dead or almost dead, but could be perhaps patched into another life.
Small icy objects are very suitable for a scheme such as you have proposed Antius.
Ice Giants, and Saturn, just maybe could support floating robot devices which harvest energy.
Callisto, has a wide distribution of chemicals, and perhaps just enough solar energy.
Titan is unique, but usable per some variable desires/solutions.

But Plutoids have no reasonable solution that I am aware of yet. They at best can then be a dump of light chemicals, and they could perhaps temporarily be pressurized, but I hate waste for silly things.

Maybe someone else will figure something out.

Sorry for wasting peoples time.

Tom Kalbfus · 2016-10-21 22:10:24

Antius wrote:

I think Titan may be a special case. Its escape velocity is 2.3 times greater than Pluto. Even at Titan temperatures, Pluto would lose atmosphere quite rapidly. I do not know what the half life of a 1 bar atmosphere would be, but to produce a 1 bar surface pressure, the column density would need to be ~20x greater than Earths. At such reduced gravity, the scale height would be many times greater than Earth's and the atmosphere would extend a long way out into space. The higher you go, the lower the local escape velocity and Pluto's surface Ve is only 1200m/s.
Thats not to say that Plutoids wouldn't have their own advantages. The abundance of nitrogen ice would provide an excellent heat sink. And any atmospheric pressure at all reduces the difficulty of building a habitat. If a body is dominated by water ice, then habitats could be constructed within ice covered lakes. An atmospheric pressure of 1KPa would be sufficient to suppress evaporation at 0C. Under Pluto gravity, 160m of water would produce a 1bar pressure. Under Sedna gravity, roughly twice that depth would be needed. Pluto may be problematic as its entire crust is dominated by frozen nitrogen, although there are sizable inclusions of water ice floating on the nitrogen crust.

What if you turned Pluto inside out?
Here is a variation of my artificial world idea:

the outer cylinder definitely rotates once every 90 minutes to produce 1-g
the inner optical cylinder might or might not rotate, it is separate from the outer cylinder, it does not need to have gravity, and probably would be easier to build and maintain if it did not. There is a gap between the walls and the inner cylinder, large enough to fly a spaceship through if desired!
The Solar Flux tube is the source of illumination, and at the bottom of this illustration is the fusion reactor that powers it. The fuel tank storage is not shown in this diagram, as this is not a spaceship, the fuel could be stored anywhere and delivered to the fusion reactor as needed. To a person standing on the floor of this cylinder, it would almost appear that he was standing on the surface of a planet, the sky above would be blue, the Sun would appear to rise in the east and set in he west, there would be stars in the night sky. The horizon would be indistinct and a blur if you looked north and south, and the surface would appear to curve upward, to meet a sharper sky horizon as you looked east and west. As you walked further from the equator of the cylinder, the sky would produce an image of the Sun that reaches its zenith lower above the horizon, days would get longer in the summer and shorter in the winter the further north or south you walked away from the equator. if the landscape was rugged, the horizon would be the peaks of mountains and hills in the distance, and the view would be indistinguishable from an Earthly landscape.

Last edited by Tom Kalbfus (2016-10-21 22:20:39)

Mark Friedenbach · 2016-10-22 02:13:25

Void, you're assuming Earth-like biology. There us no reason the creatures that colonize the plutoids need to be carbon-based life forms.

Antius · 2016-10-22 07:33:12

Void wrote:

Well...
That's a great pity. I guess I will have to fall on my sword for today. Tomorrow is another day. Still it is good to know better what the limits are.
For now, even beyond the Ice giants, in my mind, the Plutoids are the least desirable real estate.
Earth of course is the best.
Mars, is dead or almost dead, but could be perhaps patched into another life.
Small icy objects are very suitable for a scheme such as you have proposed Antius.
Ice Giants, and Saturn, just maybe could support floating robot devices which harvest energy.
Callisto, has a wide distribution of chemicals, and perhaps just enough solar energy.
Titan is unique, but usable per some variable desires/solutions.
But Plutoids have no reasonable solution that I am aware of yet. They at best can then be a dump of light chemicals, and they could perhaps temporarily be pressurized, but I hate waste for silly things.
Maybe someone else will figure something out.
Sorry for wasting peoples time.

Wouldn't be too negative about it. Each new world has to be tackled according to its own merits. Two things are noticable when looking at the list of Kuiper Belt objects that have been found so far. Firstly, they all appear to be different to one another. Some are dominated by silicates, some by water ice, others have deep crusts of frozen nitrogen. Secondly, the sheer number of them is mind boggling. There appear to be dozens already greater than 500km in diameter and many more in this size range await discovery. The right solutions for colonisation will depend upon the specifics of the body.

A large body like Pluto is dominated by nitrogen ices with floating water ice mountains. Water ice would make good building material. We could probably hollow out entire water ice mountains and build large pressurised volumes within them. If nitrogen is available as liquid beneath Pluto's crust, it serves two useful functions. Firstly as an evaporative coolant for volumetric habitats. It can be pumped into a heat exchanger and simply boiled into the atmosphere. Secondly, in a similar way, it could be used as working fluid for nuclear power plants. Boil it in a boiler, pass it through a turbine and vent directly into the atmosphere. No need for bulky condensers. This allows for very compact high efficiency nuclear power plants. One could even use the nitrogen in a direct cycle passing through the nuclear core. Likewise, surface transport could be achieved using nuclear gas turbines that dump spent nitrogen into the air.

For silicate bodies, the solutions are different again. For bodies with some water ice, heat rejection could be accomplished simply by volatilising it. Habitats could either be made from rocky shells or tunnels beneath the surface, or submerged in ice covered lakes. The solutions for water ice bodies have already been discussed.

For each new world, the best solutions will be different and depend critically on the resources present. But human beings are tiny things, with short lives and short timescales. We should think in terms of adapting to a place, rather than the other way around.

Last edited by Antius (2016-10-22 07:55:19)

Void · 2016-10-22 10:07:54

Well, it's another day.
Thanks, Tom, Mark, Antius.

Tom, your designs are getting better, I agree with the double cylinder concept, it is a warping of the toroid habitat design, you just extend the length of the cylinders. In such a design, air pressure pushes compression on the inner cylinder, and tension on the outer cylinder. If you have joining tethers, between them, that could help to give strength.

I am not inclined to be as fond of the illumination method, which is not to say it is wrong, but I would simply put lighting devices on the "Ceiling" (The "Bottom" of the interior cylinder). That way it could be made of stronger materials.

As for how you transform a plutoid into such a machine, your "Inhabitants" would need to have a place to live during the process. Maybe a plutoid with a moon would give them that. Antius has mentioned Charon.

Last edited by Void (2016-10-22 10:15:27)

Void · 2016-10-22 10:21:03

Mark,

I am supposing you are suggesting "Transhumanism". I guess. Not sure what form that would eventually be.

Interesting thought.

Humans I have been told go between two extremes with their view of nature, and have for a very long time. Some people want extremely groomed gardens, some want wilderness. (We have recently been in the wilderness phase I believe).

Tom is an uber groomer. Antius accepts the wilderness more, but sees the value of grooming in some cases. Perhaps like a beaver, there are certain situations where it pays to make a dam to create a pond. But not all situations.

And are you Mark the one who thinks of modifying the human instead of nature?

Interesting thing, if their is a effective/efficient form for plutoids, it is possible that two entirely different alien races could eventually arrive at the same solution for what the inhabitants of plutoids would be like. Convergent evolution, perhaps.

Void · 2016-10-22 10:23:46

Antius,

Thanks. I will pick up on the notion that not all plutoids are the same. However, so far as far as size, Pluto appears to be the largest plutoid. It could be that somewhere in the Kuiper belt and Oort cloud there are larger ones, but that is not proven at all yet, so it is speculation. I believe some speculation has it that their could be some Mars size objects.

Of course I am cheating a bit, as I have brought the Oort cloud into this, but I would be willing to call it's larger objects (If any), "Plutoids" also, if you don't mind.

https://en.wikipedia.org/wiki/Oort_cloud
Unproven speculation, but at least not mine:
http://www.space.com/7728-earth-sized-w … ystem.html
Quote:

Some astronomers say that a planet the size of Mars or Earth could be lurking on the fringes of our solar system. But even the latest space telescopes that launched in 2009 stand little chance of finding such a distant object.
Such a world, if it exists, would probably have an orbit far beyond Pluto or similar dwarf planets in the outer solar system. It would likely resemble a frozen version of Mars or Earth at best, a most unsuitable home for life. And it would not be alone.
Advertisement
"When the solar system's story is finally written, it's much more likely that it will have closer to 900 planets rather than the nine that we grew up with," said Alan Stern, a planetary scientist at the Southwest Research Institute (SwRI) in Boulder, Colo.

It seems that as it is, the atmospheric losses of Pluto have been very small over the history of the solar system. So, I am going to take a run at it again, if only to try to figure out more why Pluto cannot sustain an atmosphere. I will start another post, because this one is rather long.

Last edited by Void (2016-10-22 10:33:50)

Void · 2016-10-22 10:37:08

Pluto's atmosphere.

I would like to know what the limits are of practicality. Desiring a 1 bar pressure is nice, but perhaps not practical. Desiring a 10 mb atmosphere which would be much higher than it is now, would provide some radiation protection, but that might not matter much, if you are not going to be on the surface much. Anyway:
https://en.wikipedia.org/wiki/Atmospher … uto#Escape

However, subsequent data from New Horizons revealed that this figure was overestimated by at least four orders of magnitude; Pluto's atmosphere is currently losing only 1×1023 molecules of nitrogen and 5×1025 molecules of methane every second. This presumes a loss of several centimeters of nitrogen ice and several dozen meters of methane ice during the lifetime of the Solar System.[10]
Molecules with high enough velocity, which escape into outer space, are ionized by solar ultraviolet radiation. As the solar wind encounters the obstacle formed by the ions, it is slowed and diverted, possibly forming a shock wave upstream of Pluto. The ions are "picked up" by the solar wind and carried in its flow past the dwarf planet to form an ion or plasma tail. The Solar Wind around Pluto (SWAP) instrument on the New Horizons spacecraft made the first measurements of this region of low-energy atmospheric ions shortly after its closest approach on 14 July 2015. Such measurements will enable the SWAP team to determine the rate at which Pluto loses its atmosphere and, in turn, will yield insight into the evolution of the Pluto’s atmosphere and surface.[40]

OK, you can feel free to correct me as that is what I am after.
Gravity for Titan ~.14 g
Gravity for Pluto ~.083 g
Gravity for Triton ~.08 g

Sunlight for Titan ~1% of Earth or 100 lumens?
Sunlight for Pluto ~1/1000th of Earth or 10 lumens?
Triton? Probably about similar to Pluto.

Another difference is that Titan is in Saturn's magnetic field about 95% of the time.

Pluto seems to resemble Venus in the way it interacts with the solar wind. So there is some protection from the solar wind, somehow, otherwise the atmospheres of each of them would be gone by now, but they both have tails like comets.

Mars is the planet that the solar wind does the most damage to, and apparently this is because it has a partial fossil magnetic field, which is much worse it seems than having no magnetic field at all.

Per the quoted information the loss rate for Pluto is more than reasonable as Pluto is now. All planets loose some atmosphere to space over time. In fairness though it is thought that sometimes Pluto's atmosphere freezes out entirely (???), and so that would reduce losses over time as well.

I understand Antius is that your concern is that a very swollen atmosphere will puff up to the point that the solar wind will have a more powerful effect, and that perhaps even the sunlight could pry away molecules, due to the weakness of gravity at those distances.

For sure impactors would find it easier to remove atmosphere under those conditions, but I suspect that the rate of impacts is small.

As for solar wind, I am going to fetch information about Venus for that:
http://www.nature.com/nature/journal/v4 … 06026.html

Venus has no significant internal magnetic field1, which allows the solar wind to interact directly with its atmosphere2,3. A field is induced in this interaction, which partially shields the atmosphere, but we have no knowledge of how effective that shield is at solar minimum. (Our current knowledge of the solar wind interaction with Venus is derived from measurements at solar maximum3, 4, 5, 6.) The bow shock is close to the planet, meaning that it is possible that some solar wind could be absorbed by the atmosphere and contribute to the evolution of the atmosphere7, 8. Here we report magnetic field measurements from the Venus Express spacecraft3 in the plasma environment surrounding Venus. The bow shock under low solar activity conditions seems to be in the position that would be expected from a complete deflection by a magnetized ionosphere9. Therefore little solar wind enters the Venus ionosphere even at solar minimum.

OK, I am making the ASSumption that Pluto behaves something like Venus, but I will confess that Pluto is much smaller, colder, and I really don't know what the power of the solar wind is at that distance. I ASSume it is less, but it is the solar wind, I really don't understand it well. I could argue, that if you did not puff the atmosphere up too much perhaps the induced atmospheric magnetism could still protect the atmosphere from the solar wind, but I have no proof. I just don't know.

As for the possibility that sunlight could remove atmosphere, I am still largely ignorant, but still:
OK, you can feel free to correct me as that is what I am after.
Gravity for Titan ~.14 g
Gravity for Pluto ~.083 g
Gravity for Triton ~.08 g

Sunlight for Titan ~1% of Earth or 100 lumens?
Sunlight for Pluto ~1/1000th of Earth or 10 lumens?
Triton? Probably about similar to Pluto.

So, Pluto has about .59% the gravity of Titan, but 1/10 as much light.
So, that looks favorable to me. However I am not completely ignorant, I think the gravity of Pluto will fall off much faster as you go further out with a puffed up atmosphere.

You definitely want to puff up as little as possible, and you want to keep the upper reaches as cold as possible, down to the condensation point if possible.

So Titans working fluid is Methane, which melts at 90.7 K, but for Pluto, perhaps liquid N2 could be the working fluid, and that could be somewhat colder, melting at 63.15 K. So, a little less puffing from that, if you did it.

I am going to also presume that the heat applied would be from Fusion reactors, and that it would be applied on the surface, not from artificial suns.
There would really be no purpose to have artificial suns on a world where liquid nitrogen runs in streams and rivers.
.
So, so far, heat is the only manipulation to Pluto that was mentioned, but like Titan, perhaps a cloud deck of Tholin. Pluto has N2 and Methane in it's atmosphere now, and I would think they form, but are removed during periodic atmospheric collapse.

The cloud deck could be both harmful and useful perhaps. It would interfere with radiating heat to the universe which is what a liquid Nitrogen worlds primary value would be (Along with a presumed 1 bar atmosphere), but it would also allow the upper atmosphere to be cooler, which would help to reduce the risk of atmospheric loss.

I could also call in the dreaded Hall Weather Machine (Per Karov), and propose to have a thermal regulating blanket that way.

But gravity falls off pretty fast on Pluto, perhaps indeed, at the puffed up altitudes, there simply would not be enough gravity to wrestle with both the solar wind, and possible losses to solar radiation. I will defer to your judgement Antius finally, however, I will suggest that perhaps an object larger than Pluto (Not planet 9) could lurk in the Oort cloud, and perhaps it would be large enough to "Titanize" (Sort of).

Fishy Science:
http://www.dnr.state.mn.us/fish/burbot.html

Long post. Sorry!

Last edited by Void (2016-10-22 11:55:08)

Tom Kalbfus · 2016-10-22 11:45:18

Void wrote:

Well, it's another day.
Thanks, Tom, Mark, Antius.
Tom, your designs are getting better, I agree with the double cylinder concept, it is a warping of the toroid habitat design, you just extend the length of the cylinders. In such a design, air pressure pushes compression on the inner cylinder, and tension on the outer cylinder. If you have joining tethers, between them, that could help to give strength.
I am not inclined to be as fond of the illumination method, which is not to say it is wrong, but I would simply put lighting devices on the "Ceiling" (The "Bottom" of the interior cylinder). That way it could be made of stronger materials.
As for how you transform a plutoid into such a machine, your "Inhabitants" would need to have a place to live during the process. Maybe a plutoid with a moon would give them that. Antius has mentioned Charon.

Actually the blue area is the atmosphere, because of the centrifuge, it never gets up high enough to push against the atmosphere. the inner cylinder is just a giant curved television screen, it also hides the landscape above, it redirects the light coming from the central flux tube, to produce fictional images of an Earth like sky. What you would see if you were walking on its surface would appear to be the surface of an Earthlike planet, the only thing that would give it away is if you are on a very flat landscape and can see all the way out to what would be the horizon, in a hilly or mountainous setting, it would look just like the surface of the Earth. the inner surface according to my drawing which is scaled 10 kilometers per pixel, is 510 kilometers above the floor of this cylinder, th atmosphere attenuated to a vacuum before reaching the surface of the inner cylinder, that is why you can fly a spaceship between the top of the atmosphere and the inner cylinder. The outer cylinder would spin around you once every 90 minutes, at about the same relative velocity as a spaceship in a low orbit around Earth. What one would see while between the atmosphere and inner cylinder would be a black sky above with an image of the sun and stars, and landscape and weather below, much the same as one would see while orbiting Earth, the only difference is the curvature of the ground below would be negative instead of positive, it would wrap around the artificial sky above, which is why I think the inner cylinder should not rotate at all because then the spaceship could dock with it, perform maintenance in zero gravity, or close to it.

Void · 2016-10-22 11:57:08

That's very imaginative Tom. Far out. And far out of reach, but I'm not criticizing.

Last edited by Void (2016-10-22 11:57:31)

Void · 2016-10-22 12:00:24

Antius, I don't blame you if you just wander away, but, do you have a notion of a size limit for a Oort Cloud "Plutoid" that could retain a 1 bar atmosphere at low temperatures? I ASSume that the solar wind will not be much of a factor in the Oort cloud, but perhaps the interstellar flows are even more of a problem or not?

Last edited by Void (2016-10-22 12:01:12)

Antius · 2016-10-22 12:36:40

Void wrote:

Antius, I don't blame you if you just wander away, but, do you have a notion of a size limit for a Oort Cloud "Plutoid" that could retain a 1 bar atmosphere at low temperatures? I ASSume that the solar wind will not be much of a factor in the Oort cloud, but perhaps the interstellar flows are even more of a problem or not?

I do not know. I suspect in Pluto's case the atmosphere would have a half-life. The higher the surface pressure and the greater the temperature, the lower the gravity at the exosphere base, so the greater the mass escape rate. At temperatures of 50K, nitrogen liquefies at 0.1bar, so you would need to warm it up a bit to achieve a 1 bar atmosphere. According to this phase diagram, temperature would need to be at least 80K. Accounting for thermal inversion effects, probably closer to 90K, I.e Titan temperatures. It is possible in fact that Titan may have liquid N2 on parts of its surface.

http://www.chemix-chemistry-software.co … agram.html

At 6% of Earth gravity, the column density of a 1 bar N2 atmosphere would be 180 tonnes/m2. That is a lot of gas and a huge amount of energy would be needed to sublime it in the first place. According to my calculations, it would take 6E23 joules to vaporize tye atmosphere in the first place. That's 20 million GW-years, or a million large nuclear reactors for 20 years. That's a lotof energy and resources and why I think we should adapt to the environment and not the environment to us. You could probably put together a spreadsheet to work out mass loss rate as a function of gravity, temperature, surface pressure, etc. It would be a project.

At an atmospheric temperature of 90K (I.e Titan temperature) the amount of heat lost from the Plutonian atmosphere and surface would be 67TW. Thats 50,000 large nuclear reactors. If the population of Pluto grew large enough, it would happen as a natural byproduct of human presence. But it would probably require a population of at least a billion and millenia to build an atmosphere so dense. But it could be done.

A 10mbar (1KPa) atmosphere is above the vapour pressure of water. So in a limited sense, you could terraform it with a 10mb atmosphere and local nuclear heat sources to keep ice covered lakes liquid. You then build an aquatic ecosystem under the ice. That would be the path of least resistance and it would occur as a natural consequence of human habitation.

Last edited by Antius (2016-10-22 13:10:23)

Mark Friedenbach · 2016-10-22 12:50:30

Void, well that line of thinking can bifurcate in two directions.

The first is trans/posthumanist: assume people will upload themselves to machine/computer bodies and ask what the best computational substrates are at that temperature, pressure, and available resources. Carbon (for diamond) and silicon are probably still two very desirable elements for computation itself, but you also have to think about heat transfer and energy distribution. Energy will probably distributed via hydrocarbons.. a nitrogen atmosphere would be useful for heat dissipation, but liquid cooling is probably more efficient.

That's really as far as I've thought this through -- I'm too busy working on transhumanist tech at standard temperature and pressures to consider optimal low temperature, low pressure designs, but I would read with earnest speculation anyone else wants to put together.

The second is exemplified by Robert Forward's book Camelot 30K. It's a terrible book -- very little plot and character development, long-winded chemical explanations that drag on for pages -- but the speculative biology is absolutely incredible in its worked out detail and reasonableness (except the isotopic separation, but you got to allow at least one hand-wavey exception in a work of fiction). Without spoilers, the book deals with first contact between humans and a hive-like pre-technology species living on a plutoid object. The speculative biology (both chemical and evolutionary) is really interesting and relevant to this conversation -- pressurized liquid blood & internal chemistry, an energy cycle feeding on cosmic ray spallation, and a reproductive cycle enabling ecosystem spores to spread from object to object in the Kuiper belt.

Except for maybe the destructive reproductive cycle, it illustrates a wonderful basis for what life might look like in low pressure, low temperature environments. For those that are more in the wilderness camp than gardeners (I count myself in that group), it would be interesting to work out a minimally viable low-P, low-K single-celled organism would be -- probably engineered based on entirely different speculative chemistry than Earth biology -- and then guide the rapid evolution of ecosystems using targeted genetic engineering to introduce complexity and then let the results play out naturally. Every plutoid object in the Kuiper belt could have a differently evolving ecosystem overseen by its post-human occupants themselves in low-P, low-K compatible bodies.

It may seem more science fiction to someone not previously exposed to transhumanist ideas. But it is a more realistic idea of how this might actually play out.

Void · 2016-10-22 13:44:35

Antius,

Your notions seem rather sane. I would only comment, that perhaps a Plutoid would be inhabited and population growth would be allowed to be explosive, and depending on the ability of a Plutoid to hold an atmosphere, one of three things could happen.

1) The atmosphere would be inflated, and temperatures allowed to rise to the degree suiting purposes. Perhaps at that point, materials would be exported to "moons", to form Antius Aquarium worlds, or Tom spinning worlds or both. Perhaps the population growth would drop off after that, or perhaps large amounts of persons would depart in their aquarium or spinning spaceships. It is fusion after all. All the energy you want more or less.

2) A smaller plutoid could not hold an atmosphere, so you would more on to the export phase, as soon as an atmosphere began to form.

3) They just let the atmosphere drift away, after all it really isn't lost, it may be useful to the universe in forming new planemos and stars in the future.

Void · 2016-10-22 13:51:00

Mark,

I just might order that book. Maybe. Frankly since I retired, I find myself wanting to do things other that what I did previously. For instance I did a bit of programming, and for now, I'm not interested at all in it.

Hmmm....

Ya, Transhumanism is a bit of a step too far for me. It's not that I don't believe in it, I just think I am a bit too far gone for it. Everyone departs the stage sooner or later. We don't have parts in every play.

I do not have a opposition to the thinking or the effort to ponder what could be done.

It is a great pity that the human race is so powerless in reality. It only takes up new knowledge, if that knowledge satisfies some stone age instinctive programming. And in fact so many humans, almost all, have so little awareness of themselves.

So, for the purpose of hope, I do support such really out there thinking.

I'm not going to be much of a useful playmate however. Lack of ability, I am afraid.

Antius · 2016-10-22 14:42:05

On an old space studies institute website, I can remember discussions on a nuclear powered subselene. This was a nuclear powered tunnelling machine that would literally melt its way through lunar rock, producing tunnels and potentially casting blocks from the molten basalt. I cannot find any reference to it on Google now. The problem with doing this on the moon is the temperatures needed to melt rock, which challenges fuel temperature limits. Molten rock is both corrosive and abrasive.

On icy bodies it would be much easier to build and use a device like this, as it would only need to reach temperatures of a few hundred degrees and could use light water reactor technology. Using a device like this, a small team of people could excavate city sized 1 bar pressurised spaces on icy bodies before any humans arrive.

A 700kW device would melt 1kg of ice per second. So a 700kw device would bore 1.1metres of 10m wide tunnel per day. If the core lasts for 10 years, the reactor would melt a tunnel some 4km long. We could deliver this remotely to an icy body. If the drill includes a power generation cycle and dumps heat by melting ice, it can also generate oxygen using an onboard electrolysis unit. After 10 years the humans crew turn up and the drilling reactor is shutdown. The crew have ready-made living space.

In terms of oxygen generation, it takes about 25MJ to produce 1kg of oxygen and 1kg of O2 generates 4m3 of habitable space. If the tunnelling machine generates 200kw of electrical energy, then it can produce 28.8kg of oxygen per hour. That is sufficient to keep pace with the rate of tunnel production.

Last edited by Antius (2016-10-22 15:28:45)

Void · 2016-10-22 15:33:21

Yes, that seems quite reasonable, and perhaps a good way to start a presence.
I might add the possibility of a prior impact creating a lake of water, that of course perhaps being then used to grow food somehow, but it is not a necessary item. If you have fusion energy, and ice, and traces of everything else, you have got a lot.

A Segway of course; about the atmosphere, thick or thin, the solar wind is deflected from it for the most part, by a induced magnetism. This really makes me wonder about magnetism and the flow of electrons or (+)ions in the atmosphere of such a place. I don't have any point of leverage, we don't know enough yet, but wouldn't it be completely something if somehow this could be a generative machine that somehow humans could tap energy out of? After all the upper atmosphere of plasma, deflects a flow of solar wind plasma. Solar wind flowing around a stator?

It's a long shot, it may even be true, but cannot be accessed for energy, but still I am going to have my receiver tuned in on this one. I am very interested.

Last edited by Void (2016-10-22 15:38:11)

Terraformer · 2016-10-22 16:57:01

Re. atmospheric escape, the escape velocity of Pluto is 1.2 km/s. At an exosphere temperature of ~90K, the average velocity of the molecules would be >300 m/s, 4x less, so it should be able to hold on to the atmosphere for a very, very long time. Even if the exosphere rises to ~250K (which I would only expect to happen if the surface was completely paraterraformed), the escape time should be measured on the millions to tens of millions of years. The atmosphere would be wedge shaped (which is why you can discount the reduction in gravity - the atmosphere spreads out at the same rate the gravity reduces, so you end up with the same scale height as if you treat it as a flat surface with constant gravity). If the body is not spinning rapidly, and thus avoids the centrifugal effect which makes terraforming Ceres so tricky, there shouldn't be a problem.

Now the energy issue is something different entirely. You could use impactors, perhaps. Alternatively, if you have a civilisation that routinely manufactures solar sails, you could use a mirror 5-10 times as wide as the planet to focus sunlight on it...

Tom Kalbfus · 2016-10-22 23:06:42

Void wrote:

That's very imaginative Tom. Far out. And far out of reach, but I'm not criticizing.

Most things are out of reach for me, I am 1 year shy of 50 years old, My Uncle died at 69, My mother died at 52, My father is still alive in his seventies, my maternal grandmother lived to 94, so I figure I probably have 20 more years of life left in me. So when we talk about terraforming, its all the same to me. I am hoping for some medical miracle, or artificial intelligence in te next 20 years, so that I might live longer and see further progress. Anything that occurs past my natural lifespan is all theoretical to me, just like theoretically, I might live past 100 years old, but I'm not counting on that! I guess what I'm trying to do here is throw some ideas out, so they don't stay in my head when I eventually do die. These ideas might live on past my death, and maybe some future generation might do something with them.

Last edited by Tom Kalbfus (2016-10-22 23:09:00)

Antius · 2016-10-23 07:30:22

A Plutonian ice cave?

WAX_9Ap

Antius · 2016-10-23 08:07:45

Will try again...

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