The Case for Titan

Tom Kalbfus · 2013-11-02 23:27:10

Titan already has a substantial atmosphere that is 98% Nitrogen with a surface pressure around 1.5 bars, to make it Earthlike, we need to add 20% oxygen, this would increase the surface pressure to 1.87 bar with a nitrogen/oxygen atmosphere, then we increase the Sunlight levels, this requires a solletta around Titan that is 60,000 km wide, and about 180,000 km in radius to gather enough sunlight and concentrate in on Titan, for comparison, Titan is 1,180,000 km to 1,250,000 km from Saturn and Saturn is 60,000 km in radius, so there is definitely room for such a solletta. I suspect this is farther than Titan's L1 point, so an orbit around Titan at this distance may not be possible, or the hoop would have to be strong enough to resist Saturn's tidal forces, spinning the Solletta at faster than what would be orbital speed may create enough centrifugal force to keep it circular against Saturn's tides. Lets do some rough calculations gravity of Saturn a 60,000 km is 1 g, at Titan's closest distace minus the 180,000 km radius around Titan, (1,000,000 km) the gravity would be at 16 and 2/3rds Saturn radii 1/ that numver squared or 1/278 times Earth's gravity at 1,360,000 km from Saturn that is 22 and 2/3rds Saturn Radii and so the gravity would be 1/514th of Earths gravity, about half as much at the far end of the Solletta as at the near end. The Gravity of Titan is 0.139 times Earths and 180,000 km is 70 Titan radii, gravity from Titan would be 1/35250 that of Earth so its practically non-existant. If the soletta rotates once every 75 hours, it will generate about 0.01 of Earth gravity, this is greater than the gravitational differental between thenear and far ends of the Solletta from Saturn, so it could hold a roughly oval shape that would be adequate to intensifying sunlight on Titan and warming it up, the supporting cables would have to be made of strong stuff however.

The next step after warming Titan up is to prevent its atmosphere from escaping into space, for that we need a transparent shell made of plastic, the other problem is a significant portion of Titan's ices is probably dry ice, we don't want that adding to the atmosphere when it turns into a gas, maybe we should wrap that up in an innershell and put a surface on top to weigh it down as it melts or sublimates. I suspect the inner shell will expand as the gas pressure builds up beneath as Titan absorbs heat.

Terraformer · 2013-11-03 03:44:05

Titan would be in no danger of losing it's atmosphere within unreasonable timescales. The calculation's around here somewhere. Apparently it could hold on to it's atmosphere a good long while, even with an exosphere the same temperature as Terra. Thermal loss would be dominant, given it's distance from the sun, and would be insignificant over Solar timescales.

My bigger worry would be the hydrocarbons. There's probably a few dozen mb worth on the surface. I'd prefer to figure out how to sequester it first, rather than having it reacting in the atmosphere and blocking out the light like it does at the moment.

I haven't heard anything about dry ice on the surface. I suppose it's possible, but we'll probably have to wait a while to know. Sending proper probes, maybe people.

RobertDyck · 2013-11-03 06:09:09

And people thought my ideas for Ganymede/Callisto were out there. I suggested a parabolic or hyperbolic mirror in orbit around the moon, 3 times the diameter of the moon. That would give the mirror 9 times collection area, but a hole missing in the shadow of the moon, so the moon plus the mirror would collect 9 times the sunlight it does now. A solletta may be a better idea. But it would have to sit in the planet's L1 point. That requires actively tracking the moon. And how do you do that for 2 moons?

Ganymede has 1/7 gravity of Earth, and Callisto has 1/8 G. My idea to deal with that is an atmosphere of oxygen and sulphur hexafluoride (SF6). That's a very heavy, inert gas; colourless, and odourless. It's also a super greenhouse gas.

Putting a shell around an entire celestial body to contain atmosphere is called a world house. The problem with a world house is meteorites. They happen every day, and will puncture your world house.

But the big problem that just can't be fixed is distance from the Sun. Your solletta is just too big.

Tom Kalbfus · 2013-11-03 06:41:21

Saturn is about 10 AU from the Sun and so is everything orbiting Saturn, that means the cross section of the collecting mirrors have to be 10 times the diameter of the World they would focus their light on which in the case of Titan is 5,150 km in diameter, so we need a collection cross section of 60,000 km just to gather the necessary light, then generally I make the radius of the light collection ring to about 3 times its width, its actual thickness is insignificant on these scales, if it weren't for the dim light, we could get away with an illumination ring of 6000 km width and 18000 km radius, and I think that is within Titan's gravitational influence, using the same method for reflecting light around Venus one could create a 24-hour day/night cycle. Alternatively once can simply generate artificial sunlight and power it with a fusion reactor. A fusion reactor on this scale would be huge, it would involve the creation of a powerful magnetic field to contain the plasma in a ring outside the illuminating surface of Titan. A tokamak toroid reactor about 1 km wide and 18000 km in radius around Titan, and as many of these rings as required north and south of the orbital plane would generate the required energy. The energy would be collected for the purpose of generating electricity, and then on one spot along the ring a plasma would be heated by microwaves to 6000 degrees kelvin which will reproduce the illumination effects of the Sun.

Alternately a Saturn Solletta would be 3,600,000 km in radius (Outside the orbit of Titan) and 1,280,000 km wide, while most of the light would be focused on Saturn, some of it can track Titan, and a smaller Solletta 18000 km in radius and 6000 km wide would intercept that and reflect it around Titan to produce a 24 hour day/night cycle without a giant fusion reactor. The other Moons orbiting Saturn would simply be used as construction material for these giant mirror arrays, including Saturn;s rings Earth intensity sunlight would sublimate them anyway as they are mostly water ice.

A Saturnian Solletta would be huge, it might be easier just to build a giant fusion reactor For Saturn, you need an illuminating Artificial Sun surface of a radius of 360,000 km and 60,000 km wide for Saturn with a fusion reactor behind it.

Terraformer · 2013-11-03 08:28:36

Or, you know, we could just let Titan be by and large a gloomy world, and supply lighting where we need it. Plants don't actually need 1.4kw/m^2, they max out at 100W/m^2. Use fusion powered airships if you want to light a major area, and grow your crops under artificial lighting.

Tom Kalbfus · 2013-11-03 09:49:26

The thing is titan can absorb a lot of heat. One can grow plants under a dome that is heavily insulated and artificially illuminated inside. To terraform Titan means heating the entire planet to Earth normal temperatures, otherwise its not terraforming. So long as Titan is as warm as Earth, it might as well be illuminated as well and we'll need a surface to grow plants on. Titan will likely be a water world if heated to Earthlike temperatures, but that may be fine, and Earthlike atmosphere will have a pressure close to 2 bars at its ocean covered surface, humans may prefer to hover at the 1 bar level of the atmosphere at 1/7th of Earth gravity flight is easy to achieve. I wonder what the terminal velocity would be for a human falling towards Titan's global Ocean if dropped from the 1 bar altitude to hit the ocean at the 2 bar altitude, would such a human survive a fall like that without a parachute, or would the terminal velocity still be too high when he hits the ocean for a safe dive?

Void · 2013-11-14 11:13:21

You have caused me to wonder if the following could be done:

Place a honeycombed floating shell in the mostly N2 atmosphere of Titan, so creating multiple zones, (1) the atmosphere above the honeycomb shell,
(2) the atmosphere below the honeycomb shell, (3) and of course a multitude of enclosed chambers incorported into the honeycomb shell.

If greenhouse gasses which will not consense could be pushed into zone 1, then below that could be kept as vaporized a significant amount of Methane,
as a further greenhouse gass.

Presumably the (3) honeycomb shell chambers could be partially filled with Helium for flotation, and if they were warmer inside that would also aid flotation.

Heat directed into zone (2) would eventually melt everything to an ocean, and also likely release a huge amount of hydrocarbons, which would have to be
mechanically moved to zone (1). In zone (1), those hydrocarbons could be exported from the world, and hopefully sold to a buyer. This would eventually allow a N2 atmosphere in zone (1) and a N2/O2 atmosphere in zone (2), but you would want to make sure that the amount of combustable gasses in zone (1) was kept below the flamable limt, in case zone (1) and zone (2) atmospheres got mixed.

Eventually when the ocean of Zone (2) existed, a very large amount of hollow floats made of plastic could be dropped into the ocean. They would have
anchors for plants to root onto, and would likely collect into rafts. Bog plants modified could cause them to become floating islands. Of course
zone (2) would need artificial lighting for bog plants to grow, but then as much of the ocean as was desired could be covered in this manner. I believe
that normal plastic objects can persist for quite a long time. A method would be required however to keep them from becomming waterlogged over a long
period of time.

If zone 2 were to have a temperature near freezing in the areas of bog, then it could be a floating permafrost bog. Otherwise at elivated temperatures
where trees grow on the floating bog, it still might be able to support the weight of a person, especially under a .1 g (Approximately) situation.

It might be possible to have one hemisphere as tropical, one as arctic, and a transition band of temperate between them. For the arctic hemisphere,
then it would be required that the honeycomb shell above that area would not be heated on average above freezing. To allow ice to form, the lights would
be turned off periodically.

Minerals could be extracted from the water, although the core is likely surrounded by several types of pressurized ice I speculate without proof,
minerals from the core may travel to the water ocean if cyro-volcanism occurs in that pressurized ice.

Tom Kalbfus · 2013-11-14 12:49:56

The greenhouse effect would really be an insignificant part of the terraforming strategy for Titan. At the distance of Mars from the Sun, the Greenhouse effect can perhaps make up for some of the extra distance between Mars and the Sun, but Saturn and its moons are ten times the distance as the Earth is from the Sun, and it receives only 1/100th of the energy the Earth receives per square meter. Or to put it another way Saturn receives about the same amount of sunlight as the Earth does even though Saturn is ten times bigger!. What we need to do is add sunlight, we need mirrors that are ten times as large as Titan and focus the sunlight those mirrors receive onto Titan, or else we can provide an artificial means to Illuminate titan. whichever is easier. I think simply by the fact that Titan has low gravity means that even if its atmospheric composition is the same as Earth's the greenhouse effect will be greater just due to the extra mass of atmosphere that will be required to provide 1 bar of air pressure at the surface. There is probably a lot of carbon dioxide frozen on Titan's surface, if you heated it up to room temperature that carbon-dioxide will be a gas, and we have to do something about that, as we don't want too much carbon-dioxide, one could perhaps split it up to carbon and oxygen to make the air breathable, clean up the other poisonous gases for a breathable atmosphere, and what's left of the crust will be an endless global ocean. Titan has a gravity of 0.139 that of Earth The air pressure will be close to 2 bar with the oxygen added, so its atmosphere would stack 14 times as high as on Earth that is about 1400 km if you consider that Titan's diameter is 5150 km that means the diameter with atmosphere will be about 7950 km, that is a lot of air!, the breathable portion of it will be 140 km high! Flight would be easy in this atmosphere, falling into the ocean need not be a serious concern, as we could have floating islands over this ocean.

The thing is though, your can't place a solletta around Titan the way you could around Mars or Venus. A solletta would have to collect 100 times as much sunlight as Titan now receives and it would have to be 10 times as wide. A solletta around Saturn would do the trick The thing about the Saturnian solletta is that Saturn is 10 times as wide as Venus 120,000 km instead of 12,000 km, you can't have a solletta that is ten times as wide that is 128,000 km north to south and 390,000 in radius as that would not collect enough light for Saturn, you'd need a solletta that is 1,280,000 km wide and 3,900,000 km in radius in orbit around Saturn, there is no point in going to the Saturn-Sun L1 point as that would require an even larger Solletta. The Saturn Solletta would focus sunlight on Saturn, but a portion of that light could be focused on Titan. Titan's orbit is inside this radius. Saturn is the big prize for terraforming however, if we could place a shell around Saturn, we could have a surface to live on that is 95 times the surface area of Earth. I am sure Saturn contains enough nitrogen and oxygen for a 1 bar breathable atmosphere on top of the shell. It should have plenty of water too, the water cloud level of Saturn would be deep inside Saturn's atmosphere, just have to bring it up and place enough of it on top of the shell to make an ocean. Gravity on Saturn is about the same as on Earth. Might as well cover the shell with a global ocean, as there will be pressure waves under the shell that will cause the shell to undulate like the waves of an ocean, place water on top of that and you have an endless ocean with waves and you can place floating structures on top of that, maybe like oil platforms to create some stability against those waves. The waves will be quite sizable as there would be nothing to stop them. Perhaps low flying balloons will be the way to go. weather systems will be huge but temporary under Earth level sunlight.

Last edited by Tom Kalbfus (2013-11-14 13:13:52)

karov · 2013-11-14 13:07:40

Everything is about Watts per square meter.

In case the total light flux which could be focused on the planet -- without the space optics used to go outa aesthetical proportions -- is too small, we could always play out the trick with the Illumination Oasis - a sunspot on the planet - dozens, or hundreds, or thousands of km wide where all the light goes.

Titan gets 1/100 of the Earhs level of illumination in W/m2? OK. Just instead of illuminating the whole concentrate ( via Hall's Weather Machine ) all the incident light on 1/100th of its surface. Which is still about a million km2! The rest of the planet's atmosphere however in eternal darkness won't freeze away on surface due the heat circulation -- the incident sun light is not diverted, the flux has the same magnitude, the planet is neither impoverished or enriched with energy...

Eternal daytime. If the spot is on a ice-shell little world like these circum-gas-giant planemos, then the spot will melt the ice down to the liquid water = bottomless ocean surrounded by steep or not so steep icy cliffs , onto which the whole local civ could be hanged on.

Similar to Karl's Schroeder Permanence's Oculus world.

Atmospheric composition differences? Just put molecular sifting mesh via inflatable support mesosphere high around and leave sky open...

Last edited by karov (2013-11-14 14:15:21)

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#1 2013-11-02 23:27:10

The Case for Titan

#2 2013-11-03 03:44:05

Re: The Case for Titan

#3 2013-11-03 06:09:09

Re: The Case for Titan

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#6 2013-11-03 09:49:26

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#7 2013-11-14 11:13:21

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