Terraforming Neptune

Tom Kalbfus · 2007-09-29 21:55:43

This made me think of using a mirror array (made up of many individually movable mirrors) on the surface of Mercury to achieve the same job [focusing heat on Jupitor's moons]. ...
Perhaps each segment can be built on the cold side and transported around to the hot side when completed.
Hi all, Michael.
The mirrors will be sending the light typically 930 million km. To create a mirror with a focal length with this precision will require the reflecting surface to be optically smooth at the sub-atomic level. These giant mirrors will have to flex to keep the moons in focus. They will have to adjust for the heat causing them to expand and change the focal length, etc. I don't see it being physically possible.
Mercury does not have a cold and hot side. It rotates 3 time every two orbits.
Warm regards, Rick.

The sort of lasers proposed to propel light sails to interstellar distances, might instead be aimed at Jupiter's moon's and focused so that the laser light intensity equals the sunlight wattage experienced on Earth. One possible candidate for terraforming might be Neptune.

Terraformer · 2007-10-06 10:16:33

The moons or the planet. The planet to me sounds like a big super earth.

Tom Kalbfus · 2007-10-06 16:13:23

Neptune could hold onto to such an atmosphere at Earth temperatures, its moons could not.

Terraformer · 2007-10-07 02:58:35

New Thread? Possiblity of Terraforming Neptune?

Antius · 2007-10-08 01:52:31

Question: Does Neptune actually have a solid/liquid surface? It's atmosphere is almost pure hydrogen/helium if memory serves and it's temperature is about 40K.

Tom Kalbfus · 2007-10-08 10:43:02

Question: Does Neptune actually have a solid/liquid surface? It's atmosphere is almost pure hydrogen/helium if memory serves and it's temperature is about 40K.

Boil it away and what do you have left? Neptune, I believe is a water world, it's global ocean lies beneath a crushing atmosphere, but what if we remove that crushing atmosphere?

karov · 2007-10-09 06:12:21

Question: Does Neptune actually have a solid/liquid surface? It's atmosphere is almost pure hydrogen/helium if memory serves and it's temperature is about 40K.
Boil it away and what do you have left? Neptune, I believe is a water world, it's global ocean lies beneath a crushing atmosphere, but what if we remove that crushing atmosphere?

Too huge power expenditure ( pure loss!!! ) for lifting. Yes, the surface gravity is OK ~1 gee , but the escape velocity is much higher than on earth. Better to do the things in the right direction which also gives us profit of energy -- the Neptune moons possess thousands of times the mass necessary to build stable floating shell over the moon. such shell with "caged" atmosphere would decrease the energy requirements for illumination many times... In one extreme but elegant scenarion the new shelled neptune will not need solar illumination at all -- just dump in it short-period cometary stuff onto it using electromagnetic and / or eletrctrostatic tether methods. The infalling stuff could be in ready form of goods for the market, and the world to be illuminated electrically only from the "waste" energy produced by the controlled descending of mass to lower position.

The simulations show that at the time of formation of the solar system there were not 1 but 5 Neptunes and 4 of them were billiarded away -- the Deepm Oort Cloud could occur to hide some of these rogue neptunes and utilization of local gravitational potential energy wealth could be feasible.

Tom Kalbfus · 2007-10-09 10:28:41

Question: Does Neptune actually have a solid/liquid surface? It's atmosphere is almost pure hydrogen/helium if memory serves and it's temperature is about 40K.
Boil it away and what do you have left? Neptune, I believe is a water world, it's global ocean lies beneath a crushing atmosphere, but what if we remove that crushing atmosphere?
Too huge power expenditure ( pure loss!!! ) for lifting. Yes, the surface gravity is OK ~1 gee , but the escape velocity is much higher than on earth.

That's just it, since the escape velocity is greater than Earth's, it can certainly hold on to an Earthlike atmosphere. It would be necessary to heat up Neptune so that the average velocity of the free hydrogen molecules is greater than the escape velocity, but such that the average velocity of the oxygen, nitrogen, and water molecules is less than the escape velocity. We would then boil down Neptune's atmosphere until it is something lighter and more Earthlike than what it is now. If most of the hydrogen and helium escapes, we'd be left with the heavier gases and a global ocean of water which makes up most of the planet, surrounding a rocky core in the center. Neptune's rotational period of 16 hours, 6 minutes and 30 seconds is not bad. The name Neptune would be very appropriate in this case as it would be a water world, it would still be blue with lots of weather and hurricanes, its size would remain much the same, probably the loss of its atmosphere would be compensated by the expansion of its ocean as it heats up. Neptune has a mass of 17 Earth's.

nickname · 2007-10-09 17:28:36

The only way i can think of boiling away Neptune atmosphere is with a runaway fusion or fission reaction in the atmosphere.

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.
We are talking about a much larger than Earth sized lens on mercury.
Or we might get away with one about the size of Earth close in to the sun.

I think the escape velocity of the remaining terra formed Neptune would also be just beyond our abilities to escape with current technology

Just a few tech glitches

Tom Kalbfus · 2007-10-10 11:33:34

The only way i can think of boiling away Neptune atmosphere is with a runaway fusion or fission reaction in the atmosphere.
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.
We are talking about a much larger than Earth sized lens on mercury.
Or we might get away with one about the size of Earth close in to the sun.
I think the escape velocity of the remaining terra formed Neptune would also be just beyond our abilities to escape with current technology
Just a few tech glitches

I think terraforming Mars is beyond our current capacity right now too, since we are not on Mars. I do think terraforming Mars is easier to do than terraforming Venus and that terraforming Venus is easier than terraforming Neptune.

I do think that any planet that has close to Earth's gravity at its surface that is also in the outer Solar System will tend to be the size of Neptune, an Earth-sized planet of the same density would have one quarter to three tenths of Earth's gravity and an escape velocity of 3-4 km/second. The planet would be made mostly of ice, and would probably have an atmosphere with a surface pressure greater than Earth, but I think this would not be a proper target for terraforming. I suppose an icybody with a Marslike gravity is not out of the question, but warm it up to Earth temperatures and you still have a global ocean but with Mars gravity or less. Holding the diameter at one Earth diameter, the escape velocity should be proportional to surface gravity. If you want to duplicate Earth's gravity environment, you'd probably have to start with an Neptune-sized planet. All that light stuff tends to accumulate during planetary formation when you are far from the Sun.

nickname · 2007-10-12 05:23:47

Tom Kalbfus,

I think Mars is a pretty easy place to alter into a more human friendly world.
Just scrapping off the dust from phobos and allowing it to bombard the poles would completely alter Mars atmosphere.
But could we ever call the place with an atmosphere of nearly 100%co2 terraformed?

All the candidate worlds for terraforming are missing key elements to attempt terraforming.
Mars Nitrogen, Venus Water, The Moon pretty much everything.

Beyond Mars the worlds are either so bathed in radiation or so cold, that without radical technologies i think they are at best just temporary landing posts.

With the exception of Titan, i don't believe we will colonize any other worlds other than Moon and Mars.

No real need to try and terraform The moon, just use it as a giant space station.
Mars on the other hand we should try and make the place as comfortable as possible, but terraforming Mars to anything like earth will require lots of nitrogen.
Maybe the goal for Mars should just be friendly first, then the laborious long term import of nitrogen.
Venus is a good candidate to get nitrogen from.

In my opinion we wont terraform any worlds because we don't need to for the moon and mars and because we cant in the case of Venus.

As for titan it is already terraformed and radiation safe, we just need to bring heated structures.

Tom Kalbfus · 2007-10-12 07:06:19

With worlds that are cold, you just add energy, and I think its a mistake to assume that this energy will just come from the Sun.

nickname · 2007-10-12 15:00:37

Tom Kalbfus,

Even on a moon sized place with a thick atmosphere like Titan.
Trying to keep it warm for 1 year would require more energy than all of earth uses for hundreds of years.
Even using fusion it would be a staggering fuel bill.
Realistic heating from the sun beyond Mars is doubtful as the structures to heat moons would be enormous, with large structures as close to the sun as mercury they would be subject to the full force of solar storms.

Heating a full sized city on a non teraformed Mars or on the Moon or Titan requires a medium sized fission reactor.

I think that is the main reason we won't terraform anything, the energy costs and time evolved to terraform are staggering.

To set up an expanding colony on a non terraformed world energy costs are quite small and time waiting is just when you have the first structure up and the heater on-line.

None of the candidate worlds can be terraformed, Mars being the best candidate lacks a inert gas allowing the C02 atmosphere to be reduced to safe Oxygen and C02 levels.
Even on a warm Mars C02 levels above 20% and nothing will grow on the surface, Oxygen levels above 30% self ignite.
If we end up with a 500mb Mars we need a similar import or 25% larger of nitrogen just to have a safe world that can have the above safe levels of gas.
Then we need to alter the C02 levels like happened naturally on earth from 50% to less than 20% so life has a chance on the surface.
This is possible to do with specialized bacteria in the water, but the wait to convert 80% of 500mb of C02 to Oxygen will take about the same length of time it took on
Earth a few billion years.
Maybe longer since Mars only receives about 1/2 the light Earth does (we will give bio engineers the benefit of the doubt here).

I say the only place we can terraform is Earth, and we are

Terraformer · 2007-10-13 10:35:03

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.

Tom Kalbfus · 2007-10-13 14:44:42

Tom Kalbfus,
Even on a moon sized place with a thick atmosphere like Titan.
Trying to keep it warm for 1 year would require more energy than all of earth uses for hundreds of years.
Even using fusion it would be a staggering fuel bill.

How do you know what fusion would cost, since we don't have it?
There is alot of hydrogen in the Universe, and if we have fusion, then all of it becomes a potential source of energy, not just that which are part of stars.

I also think there are alot of rogue planets out in between the stars, and that those bodies out number the stars, and thus the nearest one is closer to us that the nearest star.

There is a reason I talk about terraforming Neptune. I believe the nearest Neptune-sized planet beyond Neptune itself is probably an interstellar wanderer, and it is probably much closer to us than Proxima Centauri. Once we've colonized the major planets, our next target will probably be such an interstellar wanderer. Getting to a rogue Neptune-class planet will be easier, and we can relax they requirements for interstellar travel to the nearest star.

The Sun has the mass of 1.989 * 10^30 kg, Neptune is 1.024 * 10^26 kg, that means out of the material of one Sun, you can have 19,423 Neptunes, take the cube root of that, the number is 26.9, take the inverse and multiply that by 4.4 light years, and we have the nearest Neptune-sized body being 0.16 light years away on average.

Terraformer · 2007-10-13 15:27:43

And it would orbit Sol.

Tom Kalbfus · 2007-10-13 15:50:08

And it would orbit Sol.

It just may, or it might just be passing through, depends on what velocity its at, it would make very little difference to us though. If this Neptune-class planet is just passing through, it will be around for a very long time and for most of recorded history would remain at a distance of 0.16 light years, assuming it travels at typical stellar velocities through the galaxy, it would take 16 years to reach for a spaceship traveling at just 1% of the speed of light, that same space ship would take 440 years to reach Alpha Centauri. There are many more options for us to reach 1% of the speed of light than 10% of the speed of light. 1% is more confortably within the realm of fusion while 10% would require a 2 stage fusion rocket, and a plasma sail for slowing down and with that most of the launch mass would be devoted to rocket fuel. For the requirement of reaching 1% of the speed of light, you can have a reusable starship that accelerates and slows down with its rockets, it can refuel at the Neptune-class planet and then make the return journey back to Sol. If you wanted to get away from it all, a dark Neptune-class planet would be the place to go, there may be more than one. If 0.16 light years is the closest, there maybey 3 more within 0.2 light years. If one discovers a Neptune-class rogue planet, its location could be kept secret for some time, if one wants to establish a colony there and not be noticed. I think such planets would be very hard to find.

Terraformer · 2007-10-14 07:04:33

I think people would notice the shipments of CO2 from venus that would be heading towards the terraforming project. It seems to me like we'll have to teraform Mars, Venus, Neptune, Ceres, Pluto, any object, in tandem. We ahve the Carbon, we have the Oxygen, we certainly have the Hydrogen, all the materials are there. We have a huge fusion reactor right in the middle for energy, we just need the will power. The only planets to leave alone are Jupiter and Saturn for huge antimatter production facilities.

Tom Kalbfus · 2007-10-14 09:00:57

Illuminating a subgas giant to such intensity so as to blow off its outer hydrogen layers, might make such an interstellar planet more visible, especially if heated to such temperatures that it glows. I think it is the cores of these planets that we need to get to for terraforming purposes, and leave just enough volatiles behind for terraforming purposes and no more. Most planets that are large enough to terraform in interstellar space would likely be sub gas giants such as Neptune.

Terraformer · 2007-10-14 10:46:28

Except the volotiles are needed for other terraforming projects. CO2 from venus and Mars + H from neptune gives us C, H2O, and O2. Carbon could be used for spacecraft, water and oxygen, they're needed just to survive. Everythings there, it's just in the wrong place. Helium can just be used for airships for planetary travel. Get terraforming and you solve loads of problems. And we'll grow in experience that could be useful for other things.

Tom Kalbfus · 2007-10-14 12:15:24

If you are on vacation and have plenty of time to kill, then Airships work marvelously, but most people who are trying to meet a schedule prefer Jet Airplanes. I doubt Venus will obtain it voltiles from a planet 0.16 light years away.

Terraformer · 2007-10-14 12:23:29

Neptune and Uranus aren't 0.16 light years away. If you use acceleration gravity style stop travel it won't take you that long to get there.

Triton should be terraformed first. Then it can be used as a base to terraform Neptune.

Tom Kalbfus · 2007-10-14 12:34:50

Triton is a small moon. If we can't terraform our own Moon, we certainly can't terraform Triton, unless you call covering the surface with greenhouses "terraforming".

Terraformer · 2007-10-14 12:40:45

Just use it as a base for then.

Tom Kalbfus · 2007-10-15 15:55:15

Just use it as a base for then.

One can always create a miniworld.

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#1 2007-09-29 21:55:43

Re: Terraforming Neptune

#2 2007-10-06 10:16:33

Re: Terraforming Neptune

#3 2007-10-06 16:13:23

Re: Terraforming Neptune

#4 2007-10-07 02:58:35

Re: Terraforming Neptune

#5 2007-10-08 01:52:31

Re: Terraforming Neptune

#6 2007-10-08 10:43:02

Re: Terraforming Neptune

#7 2007-10-09 06:12:21

Re: Terraforming Neptune

#8 2007-10-09 10:28:41

Re: Terraforming Neptune

#9 2007-10-09 17:28:36

Re: Terraforming Neptune

#10 2007-10-10 11:33:34

Re: Terraforming Neptune

#11 2007-10-12 05:23:47

Re: Terraforming Neptune

#12 2007-10-12 07:06:19

Re: Terraforming Neptune

#13 2007-10-12 15:00:37

Re: Terraforming Neptune

#14 2007-10-13 10:35:03

Re: Terraforming Neptune

#15 2007-10-13 14:44:42

Re: Terraforming Neptune

#16 2007-10-13 15:27:43

Re: Terraforming Neptune

#17 2007-10-13 15:50:08

Re: Terraforming Neptune

#18 2007-10-14 07:04:33

Re: Terraforming Neptune

#19 2007-10-14 09:00:57

Re: Terraforming Neptune

#20 2007-10-14 10:46:28

Re: Terraforming Neptune

#21 2007-10-14 12:15:24

Re: Terraforming Neptune

#22 2007-10-14 12:23:29

Re: Terraforming Neptune

#23 2007-10-14 12:34:50

Re: Terraforming Neptune

#24 2007-10-14 12:40:45

Re: Terraforming Neptune

#25 2007-10-15 15:55:15

Re: Terraforming Neptune

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