Terraforming Neptune

nickname · 2007-10-16 05:50:10

How about we just combine two or more moons into one.

After the impact disaster clears up you might end up with a few real interesting places, still mighty cold worlds though.

Since the impacts would be in such a cold region of space the cool down time for these new worlds would be much shorter than the same sort of impact nearer the sun.

karov · 2007-10-16 06:36:24

How about we just combine two or more moons into one.

The maths work against it. If you combine N worlds with mass M and radius R , you get --

1. Volume < N x M ( cause higher mass, higher gravity = higher core compression ). The new radius is proportional to the cubic root of the new volume / i.e. roughly mass / , resp. the new surface is proportional to the square of the new radius, the new gravity is negligibely higher , a... and at the end you receive worstened figures, bad economy, bad trade of mass vs. surface and surface gravity...

Example. Take our Moon / Luna. Add into it one astronomical body which is it mass / volume analog.

The Moon has mean radius of 1 737km ( volume of 2.2x10EXP10km3 ) and mass of 7.35x10EXP22 kg , surface area of 3.8x10eXP7 km2, surface gravity of 0.1654 gees.

Now merge the moon with another moon-size chunk of mass ( same material for easiness.)

What you get is ( spherical again -- the moon is planemo, the elasticity of it can not withstand the gravity caused self-pressure !) :

Volume: 4.4x10EXP10 km3
Mass: 14.7x10exp22 kg
radius: 2 188 km
surface area: 6x 10exp7 km2 ( ~1.6 times the original )
surface gravity: 0.2 gees. ( 2 : 1.6 times the original )

vs.

two moons with total
area of 76x10exp6 km2 ( 16mln. km2 more = almost another South America )
with only 25% lower surface gravity.

For living surface with tolerable levels of surface gravity the economical interest is to split worlds not to merge them. === one Earth turned into 10 Marses = 1.5x10exp9 km2 or three times bigger area for three times lower surface gravity.

To merge moons you have benefit if only you search for utilization of the celestial mechanics potential and kinethic energy in more usefull form for the nowadays view = temperature gradient ( as the south pole of the tiny Enceladus - I`m sure that it comes from comparativelly recent impact , most probably with excentric retrograde "sister". )

nickname · 2007-10-16 17:18:20

karov,

Depends on how we impact one moon into another.
If we do the same sort of impact earth moon had, we could keep most of the heavy material on the bigger one and form a lighter material moon from the edjecta.

Two or 3 of those sort of impacts and we can create a decent sized world with a decent G level and a big moon for it.
What the heck would you call a Moons Moon anyway?

Trying to keep those worlds warm is another problem, but at close proximity to gas giants we could import what we need to make a custom atmosphere (maybe).

Terraformer · 2007-10-20 09:55:40

Gas giants atmospheres are made of nearly all Hydrogen and Helium.

nickname · 2007-10-21 04:26:39

Terraformer,

Lots of methane and amonia on the gas giants also.
Two real good gasses for building atmospheres and keeping them warm.

Getting those gasses of the gas giants is a problem in itself, but not imposible.

Is it feasable to make a moon world above the freezing point of water at those distances from the sun though?

Terraformer · 2007-10-21 07:44:49

No oxygen.

karov · 2007-10-21 10:16:30

No oxygen.

Water = oxygen.

m1omg · 2007-11-08 14:55:36

Are all of you sane?Neptune is ONLY a crushing atmosphere.The gases eventually liquifies a some point but there are temperatures of many thosands of degress.

Tom Kalbfus · 2007-11-08 17:04:21

There must be something down at the core that can be turned into an Earthlike world. The thing is, Neptune has about the same density as water with some rock thrown in. If you made a planet that was nearly all water and had a water surface gravity of about 1-g, it would be about the size of Neptune. Dump a nice breathable atmosphere in top and you have a liquid terraformed world, or at least as terraformed as a world can get if it has no surface to stand on.

nickname · 2007-11-08 18:43:21

Tom Kalbfus,

Not technically possible for us yet, but i bet a runaway fusion reaction on Neptune would do just that.
Wonder how much trouble a temporary second sun would be for earth though.
The reaction might be so violent that it fries everything in our solar system.

Another down the road (fiction) option is anti gravity.
I wonder how easy it would be to terra form pretty much any world with anti gravity machines.
All the technical problems seem to disappear on even very difficult places like Venus using anti gravity.

Tom Kalbfus · 2007-11-11 09:39:27

How about the chemical combustion of Neptune's atmosphere with imported oxygen?
That will generate alot of heat and it would turn hydrogen into water, and the remaining heat coming from the hydrogen/oxygen reaction and the hydrogen/methane reaction might cause the remaining hydrogen to escape. Ideally we would want to shed as much hydrogen equal in mass to the imported oxygen.

Where would we get this oxygen from?
perhaps from the moons, although this may not be enough, perhaps from the Kuiper Belt, perhaps a large bit of it could be mined from the Sun itself using intense magnetic fields. We want to replace a large bit of Neptune's atmosphere with a large ocean of water.

Terraformer · 2007-11-11 10:52:21

We have about sixty bars of O2 in the form of CO2 in Venus. Carbon can be used to make spacecraft, oxygen for terraforming. We have the materials to terraform every body in the solar system; it's just in the wrong place.

nickname · 2007-11-12 05:34:06

Tom Kalbfus,

The ice ball moons in orbit around Neptune could be converted into a large quantity of oxygen.
It's quite a bit of hydrogen on Neptune to convert to water though, so a very long process.

How interesting it would be to see Neptune light up as a sort of low intensity star as you fed it oxygen over many thousands of years.

nickname · 2007-11-12 05:50:41

Terraformer,

That sounds a little like my idea of not wasting time trying to terra form Venus.
Just use Venus as a fuel depot for all projects in our solar system.
When the fuel supply runs low at Venus it is terra formed sort of.
The lack of hydrogen on Venus makes it a difficult place to produce rocket fuel, but not much hydrogen is needed with liquid oxygen to make an excellent fuel.

Only problem i found for Venus being a fuel depot is that Titan is much more attractive as one, easier than Venus in every respect to fuel the solar systems projects.
No need to go hunting for anything extra at Titan, it has all the elements for rocket fuel in abundance and a low escape velocity as a bonus.

RickSmith · 2007-11-12 21:33:27

The main problem with terraforming seems to be an excess of carbon. CO2 seems pretty abundant, as does Hydrogen, so water is no object. The gas giants are made of Hydrogen and Helium so the best planetary transportation would be helium filled airships.

Hi everyone, Terrafomer.
If you wanted to put a dirigible in a gas giant atmosphere, you would have to use hot hydrogen. He is more dense than hydrogen so it would sink.

Warm regards, Rick.

RickSmith · 2007-11-12 21:42:51

...
Then the problem of trying to have 17 times the quantity of sunlight at 20 times the distance from the sun as Earth comes to mind.
That is just to keep the place warm. ...

Hi everyone, nickname.
The situation is worse than that. Neptune is actually at 30 AU from the sun, so it gets 900 times less heat from the sun than Earth and about 150 times too little light for photosynthesis. Plants require a stupendous amount of light to grow so food and air are always going to be very expensive out there.

And this is an expense that has to go on year after century after millennium.

Rick

RickSmith · 2007-11-12 21:50:06

... I doubt Venus will obtain it volatiles from a planet 0.16 light years away.

Hi everyone, Tom.
Neptune is 30 AU out, but this is only 1.678e-25 lightyears.

Warm regards, Rick.

nickname · 2007-11-13 05:08:20

Hi RickSmith,

I agree, beyond the orbit of Mars the sun becomes a pretty feeble force for warming things up and trying to make anything grow.

Other than small outposts and enjoying the view i don't think altering worlds will be an option in the outer solar system.

Fun to think about how it could be done though.
Guess if we had a semi controlled nuclear reaction on any of the gas giants the moons around them become attractive places.

Sure we would have some minor side effects from making temporary suns like frying atmospheres and radiation pulses around the solar system.
But without a little experimenting how else are we going to learn?

Terraformer · 2007-11-16 06:21:16

The main problem with terraforming seems to be an excess of carbon. CO2 seems pretty abundant, as does Hydrogen, so water is no object. The gas giants are made of Hydrogen and Helium so the best planetary transportation would be helium filled airships.
Hi everyone, Terrafomer.
If you wanted to put a dirigible in a gas giant atmosphere, you would have to use hot hydrogen. He is more dense than hydrogen so it would sink.
Warm regards, Rick.

I was referring to the other planets like Mars, Ceres, Venus, the various moons.

qraal · 2008-01-02 07:22:03

Hi All

What we need is wormholes of arbitary size and positioning - park one end at Titan and the other end on Mars to transport nitrogen, one on Venus and the other on Titan to dispose of the carbon dioxide and warm up Titan. Stick one in the Sun and one on Neptune/Uranus to dump the excess hydrogen/helium into the Sun. Orbit some really close to the Sun and use them as "artificial Suns" to warm up Mars-sized objects in the inner Oort Cloud thick disk.

A bit of gravitational physics, but we're a century or two from terraforming on such a large scale...

Terraformer · 2008-01-02 07:31:17

Grevitational energy is available that far out from the Sun (tidal stress). Maybe what we need to do is kickstart a runaway greenhouse effect on Titan.

I remember reading an article about atoms. One of the points on the timeline was synthisising Oxygen atoms. Could carbon be converted into Oxygen in the outer solar sytem?

To teraform Titan: First, start to split the Methane into Carbon and Hydrogen (the Hydrogen can be sent to Venus or just let into space, the Carbon used to construct dwelling and in the manufacture of PFCs (if possible synthesised Oxygen)). Then, warm the Moon up. Electrosise the water to get Oxygen. You now have a Nitrogen/Oxygen atmosophere. Move in.

qraal · 2008-01-03 17:50:03

A relevant paper from 2006...

Liquid Water Oceans in Ice Giants

...Ken Croswell gives a nice summary of the paper here...

No Ocean on Neptune Yet

...so once the Sun chills out Neptune's odds of forming an ocean will improve manifold - and after the Sun's AGB phase it'll probably have less H/He anyway. If the "Voyager" gravity data was correct - there's 19% odds that Neptune has an ocean now.

Of course it does have a rather pesky layer of H/He to dispose of presently - fusing them to carbon would give us a shell of diamond to build on. And 10 bars H/He + 0.4 bar O2 is breathable and non-flammable, plus it'd have a decent greenhouse effect.

Our current ignorance of Neptune's interior means we really don't know if it has an ocean or not, though odds are against it. Imagine the fishing if it did!

Terraformer · 2008-01-04 07:42:50

If only we could extact He from gas giants. If we then bombarded titan with alpha radiation some of the Nitrogen would be converted to O2.

qraal · 2008-01-16 06:06:41

Hi Terraformer

Much too hard to make nitrogen into oxygen via alpha reactions - you're wasting a lot of energy to make oxygen when it could be done by converting some of the ice and binding the hydrogen to something else.

qraal · 2008-01-16 06:21:56

Hi All

Neptune, and Uranus, suffer from the problem that they have no solid surface that's not incandescent and under millions of bars of pressure. A solid shell of diamond could be produced, the carbon made via hydrogen fusion, and the shell could then be supported by gas pressure. It would need to be incredibly strong - as diamond is - because of the rotational forces acting on it.

Alternatively we could build floating habitats of sufficiently low density to float in atmospheric conditions that better suit Terran life (say the 300 K level.) Neptune's temperature at its 1 bar level is 72 K, thus at 300 K the pressure should be about 140 bar, assuming an adiabatic atmosphere. The gas density is 14.6 kg/m^3 at that pressure (av. molecular mass is 2.6 inside Neptune, at least at the top of the atmosphere.)

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Re: Terraforming Neptune

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#29 2007-10-20 09:55:40

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#31 2007-10-21 07:44:49

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#33 2007-11-08 14:55:36

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#34 2007-11-08 17:04:21

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#35 2007-11-08 18:43:21

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#36 2007-11-11 09:39:27

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#37 2007-11-11 10:52:21

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#38 2007-11-12 05:34:06

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#39 2007-11-12 05:50:41

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#40 2007-11-12 21:33:27

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#41 2007-11-12 21:42:51

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#42 2007-11-12 21:50:06

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#43 2007-11-13 05:08:20

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#44 2007-11-16 06:21:16

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#45 2008-01-02 07:22:03

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