Terraforming Ganymede: Making Life Possible?

[athrax]

a great posibility for a planet to spread life to is ganymede. i mean, its got the basics for life; water oxygen and light ( not that much for days are are about 3.2 Earth days). the only problem is its darn cold and its atmosphere is so dense that for a human it would be like brathing on top of a mountain three times higher than mount everest. is there a posibility that we could manipulate CO2 and make ganymedes atmosphere have a high enough pressure for us to live on?

 

[LURCH]

I don't think Ganymede has a strong enough gravitational field to hold an atmosphere that thick. Human habitation would probably need to be underground.

BTW; this would probably get more responses in a different Forum. Maybe Astrophysics.

 

[cesiumfrog]

its atmosphere is so dense that for a human it would be like br[e]athing on top of a mountain three times higher than mount everest. is there a posibility that we could [..] make ganymedes atmosphere have a high enough pressure for us

I don't think Ganymede has [..] an atmosphere that thick.

I think the OP meant "thin" rather than "dense", and I'd say it's unfixable due to the weak gravity. For humans there, we'd probably want fusion power and rotating habitats, so it doesn't sound like the first site we'd want to colonise.

On the other hand (note how I make this thread relevant to this solid state forum) if our high temperature superconductor program generally fails to meet ambient Earth-temperature, the low external temperature (and low atmosphere density) of these moons might be perfect for very long efficient maglev (gravity-simulating) trains.

 

[Integral]

This topic has nothing to do with Solid state physics. Moved to general engineering for lack of a better place.

 

[MaWM]

Just one point. Ganymede is larger than Titan, which holds an atmosphere just fine. So, it can probably hold an atmosphere.. does it have the gravity to hold an Earthlike atmosphere (assuming temperture and chemistry weren't issues)? I don't know.

 

[athrax]

i guess it could not hold the atmosphere but if it could how would we manipulate it?

 

[MaWM]

Ok.. let's talk completely hypothetical. Ganymedes surface is mostly ice. If we could somehow raise it temperture, much of the surface would vaporize. This would certainly create an atmosphere. Thick one too. But nothing you'd want to breathe.

 

[athrax]

mawm,

ganymede has a crust of rock few km deep and under that is the water/ice. what would happen if we melted it? and if the gravity was increased then could we make the atmosphere breathable?

 

[MaWM]

Hmmm.. no ice on the surface? That doesn't seem right. I'm pretty sure the ice is on the top. And if we could get the world to our kind of temperture, we'dporobably get a nice atmosphere of methene, CO2, water vapor and cyanide.

 

[Quantimez]

I don't think Ganymede has a strong enough gravitational field to hold an atmosphere that thick. Human habitation would probably need to be underground.

BTW; this would probably get more responses in a different Forum. Maybe Astrophysics.

I believe it is Ganymede has a mass and gravitation similar to Saturn's moon Titan. Which has an atmospheric pressure 50% thicker than that of Earth. Those gases on Titan probably exist (Nitrogen Methane etc.) because the can exist in cold tempuratures. Both of these are natural moons mostly ice and rock. But if the ices were melted to the point of evaporation under temperatures hotter than the sun (Hydrogen bombs) with hydrofluorocarbons 1,2500 times more potent than CO2 and ozone friendly perhaps it's possible. Electrical arcs and high radiation can create ozone (O3) naturally by splitting ionization or dislocation of molecules naturally this may be possible. Think out of the box ya'll :D

 

[Quantimez]

I don't think Ganymede has a strong enough gravitational field to hold an atmosphere that thick. Human habitation would probably need to be underground.

BTW; this would probably get more responses in a different Forum. Maybe Astrophysics.

Well look at Titan for instance slightly smaller mass and size than Ganymede but with a thicker atmosphere than Earth by 50%. It's atmospheric components can be etreme of course nitrogen can exist at cold tempuratures as well as methane and ethane. Titan has lower gravitation than our moon. Both Ganymede and Titan and many satellites are mostly ice and rock.

 

[Quantimez]

Just one point. Ganymede is larger than Titan, which holds an atmosphere just fine. So, it can probably hold an atmosphere.. does it have the gravity to hold an Earthlike atmosphere (assuming temperture and chemistry weren't issues)? I don't know.

Let me add that it's easy to freeze water ice and harder to freeze nitrogen. On Earth the atmosphere is thinner at the poles and thicker at the equator. Hence it's what's the atmosphere is made of. If that atmosphere is to keep heat and stay thick further out you may wish to add more of a greenhouse gas influx.(Ozone friendly)

 

[Quantimez]

Ok.. let's talk completely hypothetical. Ganymedes surface is mostly ice. If we could somehow raise it temperture, much of the surface would vaporize. This would certainly create an atmosphere. Thick one too. But nothing you'd want to breathe.

It might depend on the type of ice your trying to vaporize. If you detonante hundreds of Tsar Bomba like hydrogen bombs across it's surface for a burning inferno of heat. Say for instance the vast majority of ices is water ice CO2 ice a a bit of nitrogen and or methane. All of it would vaporize and rise into the atmophere/ Hydrogen would split from O2 and oxygen molecules may combine and make O3 for instance(Ozone) CO2 would flow freely as a gas amplifying and trapping the 19% sunlight it gets perhaps making it warm enough for that atmosphere to stabilize if not add hydroflouro carbons later :). Note CO2 is real low in Earth's atmosphere in comparison to other gases. Thank goodness. :)

 

[Quantimez]

a great posibility for a planet to spread life to is ganymede. i mean, its got the basics for life; water oxygen and light ( not that much for days are are about 3.2 Earth days). the only problem is its darn cold and its atmosphere is so dense that for a human it would be like brathing on top of a mountain three times higher than mount everest. is there a posibility that we could manipulate CO2 and make ganymedes atmosphere have a high enough pressure for us to live on?

We may be able to terraform it dude look at the previous posts :D

 

[Quantimez]

i guess it could not hold the atmosphere but if it could how would we manipulate it?

It can I'm confident it can because Titan is able to hold one thicker than Earth both Titan and Ganymede have slightly lower gravitation than our moon. Look at the otha posts dude Lol :D. I'm optimistic

 

[Quantimez]

a great posibility for a planet to spread life to is ganymede. i mean, its got the basics for life; water oxygen and light ( not that much for days are are about 3.2 Earth days). the only problem is its darn cold and its atmosphere is so dense that for a human it would be like brathing on top of a mountain three times higher than mount everest. is there a posibility that we could manipulate CO2 and make ganymedes atmosphere have a high enough pressure for us to live on?

I have no worries about that. I don't think it's too extreme for plants not to adapt. Lol. Like an odd more time for food but having an odd more time for sunlight. We all naturally adapt to our enviroments. Like people living in high to low alttitudes. Tropical or other areas. We naturally adapt to our surroundings and may not notice it. As long as we can terraform the moon to a sufficient degree.

 

[cjameshuff]

It can I'm confident it can because Titan is able to hold one thicker than Earth both Titan and Ganymede have slightly lower gravitation than our moon. Look at the otha posts dude Lol :D. I'm optimistic

The gases that a planet/moon can hold onto are a function of temperature as well as gravity...specifically, escape velocity and mean particle velocity at the top of the atmosphere. Titan's atmosphere is thick because it is extremely cold, it would be lost very rapidly if it were warmed up to Earthly temperatures.

A far bigger problem than the rotation period is the fact that it gets only 3-4% the sunlight of Earth. That's not enough for plants to thrive...some slow-growing plants might survive those illumination levels, but they'd be limited by the low amounts of energy they receive...and not nearly enough to keep the place warm. Artificial light and heat would be a necessity, and vastly more expensive than just constructing enclosed habitats instead. Terraforming Ganymede wouldn't just be impractical and pointless, it'd be counterproductive...you'd be turning it into an insanely inefficient unenclosed habitat, and in the process destroying all the potentially useful attributes of the original environment, like the above mentioned surface temperatures cold enough for superconductors to operate with minimal cooling, or the lack of an atmosphere to get in the way of mass driver assisted launches.

This isn't pessimism...there's no planet or moon in the solar system that can be easily terraformed, but we don't need to terraform any of them, and in fact stand to benefit by taking advantage of some of their differences from Earth. Look at the other possibilities...vacuum allows greater speeds to be achieved on the surface and insulates superconductors and cryogenic fuel storage tanks, while not impeding sunlight used for solar power or launches into orbit. Frozen ices are easy to mine for fuel and burrow into for well-shielded living spaces. Etc...

 

[Quantimez]

The gases that a planet/moon can hold onto are a function of temperature as well as gravity...specifically, escape velocity and mean particle velocity at the top of the atmosphere. Titan's atmosphere is thick because it is extremely cold, it would be lost very rapidly if it were warmed up to Earthly temperatures.

A far bigger problem than the rotation period is the fact that it gets only 3-4% the sunlight of Earth. That's not enough for plants to thrive...some slow-growing plants might survive those illumination levels, but they'd be limited by the low amounts of energy they receive...and not nearly enough to keep the place warm. Artificial light and heat would be a necessity, and vastly more expensive than just constructing enclosed habitats instead. Terraforming Ganymede wouldn't just be impractical and pointless, it'd be counterproductive...you'd be turning it into an insanely inefficient unenclosed habitat, and in the process destroying all the potentially useful attributes of the original environment, like the above mentioned surface temperatures cold enough for superconductors to operate with minimal cooling, or the lack of an atmosphere to get in the way of mass driver assisted launches.

This isn't pessimism...there's no planet or moon in the solar system that can be easily terraformed, but we don't need to terraform any of them, and in fact stand to benefit by taking advantage of some of their differences from Earth. Look at the other possibilities...vacuum allows greater speeds to be achieved on the surface and insulates superconductors and cryogenic fuel storage tanks, while not impeding sunlight used for solar power or launches into orbit. Frozen ices are easy to mine for fuel and burrow into for well-shielded living spaces. Etc...

You provided good points in many areas, and you are very right in so many points. Though one underlining theme may present itself as it does today. Economically speaking cost. Also not meaning to appear pessimistic. You would have to operate carefully in a vacuum and every member working there would need protection against a variety of things while the construct these things factoring in tourism. Titan was used as an example that though it had low G relatively small size and mass its components could exist in those tmperatues in some form(Nitrogen, methane, ethane etc.) Though water vapor and CO2 would not. These are green house gases to Earth's atmosphere trapping heat. Your right Titan gets minimal light. Though Jupiter being estimated 5.2 AU Ganymede may receive just enough heat and warmth 19% of Earth. You would just have to keep it "lit" from refreezing then implying more green house gases. Perhaps after global thermonuclear detonations. You can still use solar panels at that distance and comets become active and at that distance as well underlining the possibility. The Earth's atmosphere has less than 1% of CO2 and perhaps other trace green housegases and see what it has done?!? Once oxygen splits from hydrogen in the vast amounts of water ice on ganymede. Then vaporize naturally (O3 ozone) from radiation as easily as it forms from ionizing electrical arcs on earth. Now a vacuum makes sense for space travel but in a sense of priority of pace tourism and manufacture it seems easier and a bit more cost effective to have an Earth like biosphere for relaxation looking up into the jovian sky and for working on building those materials needed further out as a refreshing nostalgic waystation. The gravity would be similar to the moon already imagine how easy would(hypothetically) for the apollo astronauts without those"bulky but light already in lunar gravitation). As landing on the moon was a fearfully but time consuming maybe and maybe not but it was indeed possible. We came from figuring out how to get into orbit toward the moon in 8 years factoring in cost. Optimistically speaking, we don't know until we try it's a maybe so or maybe not. The impossibles of yesterday are proving possible today. Mars has water ice? Short liquid flows? Before it was thought only CO2 ice existed and it's GRAV was to low to hold a thick atmosphere and a no magnetic field. Venus has no magnetic field look at it's atmosphere! Those assumptions indeed contradicted what exists in our solar system. In all confidence may I imply that its highly beneficial to terraform at minimum Mars and a moon in the Jovian system Ganymede to make to bring things from home to makes the voyage more comfortable and reasuring. Nothing great ever strived and worked for was easy. There's nothing like a blue sky for the heart.

 

[cjameshuff]

These are green house gases to Earth's atmosphere trapping heat. Your right Titan gets minimal light. Though Jupiter being estimated 5.2 AU Ganymede may receive just enough heat and warmth 19% of Earth.

When it's at 5.2 AU from the sun, Ganymede gets 3.7% of the sunlight Earth does when it's at 1 AU. I was speaking about the Jovian moons when I said 3-4%, not Titan, which gets closer to 1%. Again, plant life is not going to thrive as it does on Earth with 1/27th the light. It's not a matter of adaptability, there's just the fact of having 1/27th the energy to work with. Mars would have enough issues, with about half the light.

You would just have to keep it "lit" from refreezing then implying more green house gases. Perhaps after global thermonuclear detonations. You can still use solar panels at that distance and comets become active and at that distance as well underlining the possibility.

The possibility of what? It's not hard to evaporate water, ammonia, CO2, and other ices in vacuum. It's a simple fact that there's not much energy input from the sun out there.

The Earth's atmosphere has less than 1% of CO2 and perhaps other trace green housegases and see what it has done?!?

What has it done? It's not hard to maintain Earthlike temperatures at Earth's distance from the sun. Without that <1% CO2, Earth would have a fairly similar temperatures. A super greenhouse effect isn't going to make Ganymede Earthlike.

Now a vacuum makes sense for space travel but in a sense of priority of pace tourism and manufacture it seems easier and a bit more cost effective to have an Earth like biosphere for relaxation looking up into the jovian sky and for working on building those materials needed further out as a refreshing nostalgic waystation.

Terraforming is not remotely cost effective. It would be vastly cheaper to establish and maintain Earthlike conditions in large enclosed habitats, even on a world like Mars which is relatively well suited to terraforming. You'd be better off enclosing all of Ganymede than you would be trying to build and maintain a breathable atmosphere and sun-powered ecology there.

The impossibles of yesterday are proving possible today. Mars has water ice? Short liquid flows? Before it was thought only CO2 ice existed and it's GRAV was to low to hold a thick atmosphere and a no magnetic field. Venus has no magnetic field look at it's atmosphere! Those assumptions indeed contradicted what exists in our solar system.

The gravitational field of Mars was too low to hold a thick atmosphere. And the lack of a magnetic field has allowed Venus to lose most of its hydrogen. I don't know who assumed only CO2 ice existed on Mars, but the estimates on liquid water and such were based on the available measurements of temperatures on Mars.

In all confidence may I imply that its highly beneficial to terraform at minimum Mars and a moon in the Jovian system Ganymede to make to bring things from home to makes the voyage more comfortable and reasuring. Nothing great ever strived and worked for was easy. There's nothing like a blue sky for the heart.

Being difficult and costly don't alone make something worthwhile. As for the blue sky...it would be far easier to achieve inside a spacecraft or habitat than it would be to make Ganymede's sky blue. Even Mars, when the atmosphere is built to the depth needed to maintain Earthlike pressures in the weaker gravity, would likely have a white or orangish sky. If we're that unable to adapt to the lack of blue skies, we'll make them inside our habitats.

I don't think you've looked very much at the costs and difficulties of terraforming...you don't even appear to understand the relatively simple issue of distance from the sun, let alone the investments required, timescales involved, and returns you can expect to achieve. And there's the natural resources that would be destroyed in even a failed attempt at establishing an environment that, while taking constant effort to maintain, would be only marginally habitable to humans. It's not just expensive and difficult, it's just a bad idea.

 

[sophiecentaur]

Is terraforming an answer to anything?

 

[Quantimez]

When it's at 5.2 AU from the sun, Ganymede gets 3.7% of the sunlight Earth does when it's at 1 AU. I was speaking about the Jovian moons when I said 3-4%, not Titan, which gets closer to 1%. Again, plant life is not going to thrive as it does on Earth with 1/27th the light. It's not a matter of adaptability, there's just the fact of having 1/27th the energy to work with. Mars would have enough issues, with about half the light.




The possibility of what? It's not hard to evaporate water, ammonia, CO2, and other ices in vacuum. It's a simple fact that there's not much energy input from the sun out there.




What has it done? It's not hard to maintain Earthlike temperatures at Earth's distance from the sun. Without that <1% CO2, Earth would have a fairly similar temperatures. A super greenhouse effect isn't going to make Ganymede Earthlike.




Terraforming is not remotely cost effective. It would be vastly cheaper to establish and maintain Earthlike conditions in large enclosed habitats, even on a world like Mars which is relatively well suited to terraforming. You'd be better off enclosing all of Ganymede than you would be trying to build and maintain a breathable atmosphere and sun-powered ecology there.




The gravitational field of Mars was too low to hold a thick atmosphere. And the lack of a magnetic field has allowed Venus to lose most of its hydrogen. I don't know who assumed only CO2 ice existed on Mars, but the estimates on liquid water and such were based on the available measurements of temperatures on Mars.




Being difficult and costly don't alone make something worthwhile. As for the blue sky...it would be far easier to achieve inside a spacecraft or habitat than it would be to make Ganymede's sky blue. Even Mars, when the atmosphere is built to the depth needed to maintain Earthlike pressures in the weaker gravity, would likely have a white or orangish sky. If we're that unable to adapt to the lack of blue skies, we'll make them inside our habitats.

I don't think you've looked very much at the costs and difficulties of terraforming...you don't even appear to understand the relatively simple issue of distance from the sun, let alone the investments required, timescales involved, and returns you can expect to achieve. And there's the natural resources that would be destroyed in even a failed attempt at establishing an environment that, while taking constant effort to maintain, would be only marginally habitable to humans. It's not just expensive and difficult, it's just a bad idea.

Mars had liquid water in the past(hint of a past thick atmosphere, Titan has less than half Mars Gravity, .14 but has a monsterous atmosphere,redundancy). Mars also has evidence from the existence of ancient oceans, dried up river beds, and permafrost! Some scientists consider it to be in the "habital zone". I understand the what you mean by the difficulties but regarding how science is continually changing. There are many methods and theories to terraforming(thus there would be a variety of approaches to cost which may change). Yes it will take time as technology progresses. Today scientists are slower to say something is impossible considering the progress that's been made. (Bending radio waves around an object may be a possible prelude to bending light making an object appear invisible). Besides I understand this may be difficult. What did President Kennedy say before NASA landed on the moon? (8 years later!)"We choose to go to the moon in this decade and do the other things not because they are easy but because they are hard." Alot of NASA scientists are and have been Star Trek fans! The little portable communication device (cell phone) and other things came up from the imaginations of that generation of imaginative people as well as landing on the moon. By the way it is known that the Greenhouse gas of CO2 is important on Earth without it the planet retains less heat. If it weren't for greenhouse gases emitting from geologic activity on earth, the planet could freeze over(possible ice age). The atmosphere is thicker at the equator were it is warmer and thinner at the poles due to condensed colder gases. We know how to warm up a planet we're doing it now! All we have to do is make it convienient. If we succeed we learn how to make Earth's in the cosmos. If we fail we still learn from the data collected in the future to improve upon and use the knowledge gained for Earth's benefit. By the way, before the discoveries of water ice and other features existed on Mars, it was assumed that the polar ices were CO2 and no water existed which was applied to the general knowledge and in textbooks also before the discovery. (Mars is about 200 million miles from the sun est. half of the Earth's sunlight) The sunlight Jupiter gets about 19%(around 500 million miles from the sun) depending on the orbit. Analyzing the galilean moons in respect to their synchronous orbits and quick rotation around the massive Jupiter(88,650 miles) that most of the surface area should receive sunlight in an odd fashion after emerging from behind Jupiter from an eclypse. Though the days are longer they are not "solar days" as they revolve around jupiter, once again, synchronously. Titan indeed receives low solar energy that is why I didn't suggest it as a candidate. The logic I'm implying incudes a greenhouse gas 1,200 times more potent than CO2 hydrofluorocarbons to enhance the retaining of heat from attenuating solar energy. Atmosphere can be released from carbonate rocks and ices which Mars and some of the galilean moons might have an overabundance of. Yes there are loopholes around these things as well as in physics. You are very knowledgeable in this topic. I'm impressed :D. I believe the word for this is "possible". What is one of NASA's goals? (to extend human presensce across the solar system). People may want to breathe, taste, and feel Mars without a space suit. Thats part of the appeal and could aid in space tourism in the future. I apologize for the lengthy explanation.

 

[Quantimez]

Is terraforming an answer to anything?

In the case of humans pioneering and exploring the cosmos it can be extremely beneficial.

 

[Quantimez]

I think the OP meant "thin" rather than "dense", and I'd say it's unfixable due to the weak gravity. For humans there, we'd probably want fusion power and rotating habitats, so it doesn't sound like the first site we'd want to colonise.

On the other hand (note how I make this thread relevant to this solid state forum) if our high temperature superconductor program generally fails to meet ambient Earth-temperature, the low external temperature (and low atmosphere density) of these moons might be perfect for very long efficient maglev (gravity-simulating) trains.

Please explain Titan a moon of Saturn to me. It has gravity(.146 less than our moon) less than half that of Mars holding and atmosphere 50% thicker than Earth's? Which is mostly ice and rock in compostion with a diameter of 3,193 miles?

 

[Quantimez]

a great posibility for a planet to spread life to is ganymede. i mean, its got the basics for life; water oxygen and light ( not that much for days are are about 3.2 Earth days). the only problem is its darn cold and its atmosphere is so dense that for a human it would be like brathing on top of a mountain three times higher than mount everest. is there a posibility that we could manipulate CO2 and make ganymedes atmosphere have a high enough pressure for us to live on?

Remember Ganymede synchronously(same side faces Jupiter) rotates as it revolves around Jupiter(it's not a solar day) As Ganymede emerges from it's Jovian eclypse there is sunlight. The dark side faces away from the sun but that changes in a weird fashion as it orbits illuminating much of the surface. The other Galilean moons may have a similar function. A scientist theorized about detonating numerous hydrogen bombs with heat higher than the surface of the sun spreading shockwaaves of heat along a great expanse melting ice and releasing greenhouse gases and other gases from carbonate rocks as well (on mars). The O2 can split from water vapor and fill the atmosphere bump around and form O3 (Ozone). Hopefully an end result may be a warmer thicker atmosphere global shallow oceans. Good question!

 

[Quantimez]

Just one point. Ganymede is larger than Titan, which holds an atmosphere just fine. So, it can probably hold an atmosphere.. does it have the gravity to hold an Earthlike atmosphere (assuming temperture and chemistry weren't issues)? I don't know.

Well, the gravity is almost identical to Titan's. Titan's atmosphere is thought to mimic Earth's early atmosphere so knowing this and Titan's 50% thicker atmosphere, I believe the answer would be yes.

 

[cjameshuff]

Mars had liquid water in the past(hint of a past thick atmosphere, Titan has less than half Mars Gravity, .14 but has a monsterous atmosphere,redundancy). Mars also has evidence from the existence of ancient oceans, dried up river beds, and permafrost! Some scientists consider it to be in the "habital zone".

I'm not sure why you're bringing this up. Yes, there's evidence Mars had large amounts of liquid water and a thick atmosphere. In the past. It no longer has these because its gravity well was too shallow to keep them at the temperatures it had.

I understand the what you mean by the difficulties but regarding how science is continually changing. There are many methods and theories to terraforming(thus there would be a variety of approaches to cost which may change). Yes it will take time as technology progresses. Today scientists are slower to say something is impossible considering the progress that's been made. (Bending radio waves around an object may be a possible prelude to bending light making an object appear invisible).

Irrelevant, but no, those "cloaking" developments will never lead to being able to make objects turn invisible. They operate in narrow bands under very particular geometric arrangements...they'll be extremely useful in development of new instrumentation and communications equivalent, but will never lead to a sci-fi "cloak".

Science is indeed always discovering new things, but some things will not change...we will not someday discover that the inverse square law does not apply to Ganymede, and that it can both retain a hot, thick atmosphere and be warmed by the sun to Earthly temperatures.

Besides I understand this may be difficult. What did President Kennedy say before NASA landed on the moon? (8 years later!)"We choose to go to the moon in this decade and do the other things not because they are easy but because they are hard." Alot of NASA scientists are and have been Star Trek fans! The little portable communication device (cell phone) and other things came up from the imaginations of that generation of imaginative people as well as landing on the moon.

Because it was hard, and because it had a very considerable scientific, technological, and political return on the investment. Being hard is not a good reason to throw away trillions of dollars and destroy vast amounts of natural resources. As for Star Trek...hate to break it to you, but it's fiction. Similarity of one or a few concepts to real-world developments does not mean that it's all reality.

By the way it is known that the Greenhouse gas of CO2 is important on Earth without it the planet retains less heat. If it weren't for greenhouse gases emitting from geologic activity on earth, the planet could freeze over(possible ice age). The atmosphere is thicker at the equator were it is warmer and thinner at the poles due to condensed colder gases.

What specific gases do you believe condense out at Earth's poles? There's only one that does so, and it typically only accounts for a few percent of the atmosphere at most.

We know how to warm up a planet we're doing it now! All we have to do is make it convienient. If we succeed we learn how to make Earth's in the cosmos. If we fail we still learn from the data collected in the future to improve upon and use the knowledge gained for Earth's benefit.

When the project fails (as it would, for reasons that would be obvious to you if you did a little research into the things people are trying to tell you about), it'll have rendered vast amounts of natural resources far more difficult to access and have sucked up enormous amounts of material, energy, and manpower that could have been devoted to doing something that was actually productive. And it's so utterly different from Earth that it'd be insanity to pursue such a project with the aim of benefiting Earth.

By the way, before the discoveries of water ice and other features existed on Mars, it was assumed that the polar ices were CO2 and no water existed which was applied to the general knowledge and in textbooks also before the discovery.

Cite a reliable mainstream source that stated it was certain that Mars has no water ice. As far as I'm aware, the polar caps were never thought to be pure CO2.

(Mars is about 200 million miles from the sun est. half of the Earth's sunlight) The sunlight Jupiter gets about 19%(around 500 million miles from the sun) depending on the orbit.

No, it gets about 3-4%. Jupiter's mean orbital radius is approximately 5.2 AU, 1/5.2^2 is 0.037, not 0.19.

Analyzing the galilean moons in respect to their synchronous orbits and quick rotation around the massive Jupiter(88,650 miles) that most of the surface area should receive sunlight in an odd fashion after emerging from behind Jupiter from an eclypse. Though the days are longer they are not "solar days" as they revolve around jupiter, once again, synchronously.

What does this matter? Their distance from the sun changes by only their orbital diameter as they do so, and eclipses only happen when they line up directly with Jupiter, so they may as well be spinning in solar orbit. That they rotate synchronously with their orbit around Jupiter is irrelevant.

The fact that they're synchronous with their orbit around Jupiter is fairly irrelevant.
People may want to breathe, taste, and feel Mars without a space suit. Thats part of the appeal and could aid in space tourism in the future. I apologize for the lengthy explanation.

That is possibly the most pointless and absurd justification for terraforming that I've ever seen. Change Mars (something vastly more believable than doing so to Ganymede, but still utterly impractical and counterproductive) so they can do this, and it won't be Mars they're breathing, tasting, and feeling. And even with our best terraforming efforts, they'd likely be gasping and looking for a heated shelter.

 

[cjameshuff]

Please explain Titan a moon of Saturn to me. It has gravity(.146 less than our moon) less than half that of Mars holding and atmosphere 50% thicker than Earth's? Which is mostly ice and rock in compostion with a diameter of 3,193 miles?

It's already been explained. It has an atmosphere because it's cold.

The mean surface temperature of Titan is 93.7 K, Earth's is 287.2 K. That's -179.5 C. It has a thick atmosphere because it's 16 K too warm for the nitrogen to liquefy into lakes and seas. At surface pressures, oxygen may be stable in liquid form...it boils at 90.2 K under one atmosphere. Surface pressure is 1.4 times that of Earth, and to achieve that in the lower gravity, the atmosphere is much, much deeper than Earth's. Titan's atmosphere actually masses more than Earth's, despite Titan being so much smaller...there's 7.3 times as much atmosphere above a given area of ground, the atmosphere is nearly a thousand km deep. Molecules at the top of Titan's atmosphere are just barely trapped by its gravity well, and if the atmosphere were warmed to Earthly levels, they would quickly escape into space.

Again, Titan's atmosphere masses more than Earth's. You'd need to transport essentially Earth's entire atmosphere to give Ganymede one that temporarily reaches Earthlike surface pressures. You'd need more in reality: a warmer, lower density atmosphere would extend further out of the gravity well, requiring more mass to reach a given surface pressure. Where are you going to get this much atmosphere, mostly nitrogen?

Jupiter's moons likely lack atmosphere in the first place because they were warmed early on by tidal friction and by heat radiated from Jupiter. Even with that, Io's the only one that got warm enough that water near the surface couldn't remain solid...we know this because Io no longer has any substantial amounts of water, very unlike its icy siblings. It lacked a gravity well deep enough to hold onto water vapor or an atmosphere dense enough to make water stable as a liquid, and if its original composition was anything like the others, it could easily have started out heavier than Ganymede. (it has 60% of Ganymede's mass now, and Ganymede is ~50% volatile ices like those Io lost...though it's quite possible it never had them, always having been too small and hot to accumulate them during its formation)

 

[Quantimez]

It's already been explained. It has an atmosphere because it's cold.

The mean surface temperature of Titan is 93.7 K, Earth's is 287.2 K. That's -179.5 C. It has a thick atmosphere because it's 16 K too warm for the nitrogen to liquefy into lakes and seas. At surface pressures, oxygen may be stable in liquid form...it boils at 90.2 K under one atmosphere. Surface pressure is 1.4 times that of Earth, and to achieve that in the lower gravity, the atmosphere is much, much deeper than Earth's. Titan's atmosphere actually masses more than Earth's, despite Titan being so much smaller...there's 7.3 times as much atmosphere above a given area of ground, the atmosphere is nearly a thousand km deep. Molecules at the top of Titan's atmosphere are just barely trapped by its gravity well, and if the atmosphere were warmed to Earthly levels, they would quickly escape into space.

Again, Titan's atmosphere masses more than Earth's. You'd need to transport essentially Earth's entire atmosphere to give Ganymede one that temporarily reaches Earthlike surface pressures. You'd need more in reality: a warmer, lower density atmosphere would extend further out of the gravity well, requiring more mass to reach a given surface pressure. Where are you going to get this much atmosphere, mostly nitrogen?

Jupiter's moons likely lack atmosphere in the first place because they were warmed early on by tidal friction and by heat radiated from Jupiter. Even with that, Io's the only one that got warm enough that water near the surface couldn't remain solid...we know this because Io no longer has any substantial amounts of water, very unlike its icy siblings. It lacked a gravity well deep enough to hold onto water vapor or an atmosphere dense enough to make water stable as a liquid, and if its original composition was anything like the others, it could easily have started out heavier than Ganymede. (it has 60% of Ganymede's mass now, and Ganymede is ~50% volatile ices like those Io lost...though it's quite possible it never had them, always having been too small and hot to accumulate them during its formation)

Indeed perhaps, remember the reason Io may not have a thick atmosphere is not because of it's gravity well which is 1/5 of Earth's but it is that the moon is closer to Jupiter than our moon is to us meaning that all the charged particles brush against Io stripping it's atmosphere at a ton per second. Io's gravitation is higher than Ganymede's and it's composition is reminiscent of the terrestial planets along with Europa. Impressive, Io's volcanism which could possibly add to an atmosphere is negated by Jupiter's radiation stripping it and forming a massive nebulae of ionized gas in the jovian system. So poor Io didn't have a chance. Nevertheless, it is not as much temperature as it is the type of gas and the conditions of a celestial body. If Io was moved to the utter most orbit away from the demolishing radiation it might begin to accumulate an atmosphere regardless with the intense heat which remains within it. Alot of the moons in our solar system are perhaps ice and rock anyway. That's a lot of frozen trapped gases from the birth of the solar system laying dormant due to lack of geologic activity and favorable conditions for an atmosphere to form. Ganymede's gravity may not be as a problem for the very reason it is mostly ice and rock. An abundance of a potential frozen atmosphere makes up much of Ganymede's mass. While having perhaps sufficient gravitation like Titan to retain it. It is further away from Jupiter and does not show significant tidal interaction as Io does. With that said, may it be said in confidence that Ganymede has a wealth of potential substance to compose a thick atmosphere. Looking at it's composition may I say it may contain a far greater abundance than required.

 

[Quantimez]

I'm not sure why you're bringing this up. Yes, there's evidence Mars had large amounts of liquid water and a thick atmosphere. In the past. It no longer has these because its gravity well was too shallow to keep them at the temperatures it had.




Irrelevant, but no, those "cloaking" developments will never lead to being able to make objects turn invisible. They operate in narrow bands under very particular geometric arrangements...they'll be extremely useful in development of new instrumentation and communications equivalent, but will never lead to a sci-fi "cloak".

Science is indeed always discovering new things, but some things will not change...we will not someday discover that the inverse square law does not apply to Ganymede, and that it can both retain a hot, thick atmosphere and be warmed by the sun to Earthly temperatures.




Because it was hard, and because it had a very considerable scientific, technological, and political return on the investment. Being hard is not a good reason to throw away trillions of dollars and destroy vast amounts of natural resources. As for Star Trek...hate to break it to you, but it's fiction. Similarity of one or a few concepts to real-world developments does not mean that it's all reality.




What specific gases do you believe condense out at Earth's poles? There's only one that does so, and it typically only accounts for a few percent of the atmosphere at most.




When the project fails (as it would, for reasons that would be obvious to you if you did a little research into the things people are trying to tell you about), it'll have rendered vast amounts of natural resources far more difficult to access and have sucked up enormous amounts of material, energy, and manpower that could have been devoted to doing something that was actually productive. And it's so utterly different from Earth that it'd be insanity to pursue such a project with the aim of benefiting Earth.




Cite a reliable mainstream source that stated it was certain that Mars has no water ice. As far as I'm aware, the polar caps were never thought to be pure CO2.




No, it gets about 3-4%. Jupiter's mean orbital radius is approximately 5.2 AU, 1/5.2^2 is 0.037, not 0.19.




What does this matter? Their distance from the sun changes by only their orbital diameter as they do so, and eclipses only happen when they line up directly with Jupiter, so they may as well be spinning in solar orbit. That they rotate synchronously with their orbit around Jupiter is irrelevant.




That is possibly the most pointless and absurd justification for terraforming that I've ever seen. Change Mars (something vastly more believable than doing so to Ganymede, but still utterly impractical and counterproductive) so they can do this, and it won't be Mars they're breathing, tasting, and feeling. And even with our best terraforming efforts, they'd likely be gasping and looking for a heated shelter.

Using logic the Earth is an estimated distance from the sun at 94 million miles avg. Mars is a little more than twice that distance(200 million miles) so it would be half. Jupiter would be at about 500 million miles away from the sun meaning about a 1/5th of the solar energy Earth recieves. The percentages your referring to is more relevant to Saturn's orbit. A simple mathematical approach diminishes the likelyhood of error nevertheless the that's impressive :D. Pulling out the whole armada I see :D. Excuse my humor.

 

[cjameshuff]

Alot of the moons in our solar system are perhaps ice and rock anyway. That's a lot of frozen trapped gases from the birth of the solar system laying dormant due to lack of geologic activity and favorable conditions for an atmosphere to form. Ganymede's gravity may not be as a problem for the very reason it is mostly ice and rock. An abundance of a potential frozen atmosphere makes up much of Ganymede's mass. While having perhaps sufficient gravitation like Titan to retain it. It is further away from Jupiter and does not show significant tidal interaction as Io does. With that said, may it be said in confidence that Ganymede has a wealth of potential substance to compose a thick atmosphere. Looking at it's composition may I say it may contain a far greater abundance than required.

What precisely in its composition makes you think it could build the sort of thick nitrogen atmosphere you'd need? You're looking for an Earth-atmosphere-mass of nitrogen in something that's mostly rock and water. There might be some ammonia there, but its presence is mostly speculation. "far greater abundance than required" of what, and how do you know this?

Using logic the Earth is an estimated distance from the sun at 94 million miles avg. Mars is a little more than twice that distance(200 million miles) so it would be half. Jupiter would be at about 500 million miles away from the sun meaning about a 1/5th of the solar energy Earth recieves. The percentages your referring to is more relevant to Saturn's orbit. A simple mathematical approach diminishes the likelyhood of error nevertheless the that's impressive :D. Pulling out the whole armada I see :D. Excuse my humor.

That's not logic, it's just bad math. You don't get to simplify inverse square falloff to simple inverse falloff...that certainly isn't going to "diminish the likelyhood of error". Mars is about 1.5 times Earth's distance from the sun (not "a little more than twice"), which does work out to very close to 1/2 the sunlight per unit area. Venus, at about 0.7 AU, gets twice the sunlight. Jupiter and its moons are 5-5.5 times the distance, which means it gets 1/25-1/30th...as I've said multiple times, 3-4%. For Jupiter, not Saturn...once again, Saturn and its moons would get around 1% of what Earth does...which is why Titan's cold enough to retain its atmosphere, despite having one full of methane and other greenhouse gases. Your estimates of the difficulty involved are wildly off because you're not even using the right scaling laws.

This is ignoring what would be blocked by the thousand-km-deep atmosphere you'd need to have Earthlike pressures at the surface, and you've said nothing about how you'll get around the issue of atmospheric loss. You can't just ignore inconvenient problems.

 

[inflector]

All these worlds are yours except Europa. Attempt no landings there.

 

[JaredJames]

I've just spent 30 minutes reading through this lot and I really wish I hadn't.

Quantimez, you clearly don't understand the basics of the maths and concepts behind simple issues (such as sunlight and atmospheric conditions) and yet you are making wild claims regarding energy and compositional makeup of these bodies.

You also don't appear to have a solid understanding of the economic side of things and are again making rather wild and extremely speculative claims regarding the justifications for such tasks (terraforming).

 

[Saturn V]

I don't think Ganymede has a strong enough gravitational field to hold an atmosphere that thick. Human habitation would probably need to be underground.

BTW; this would probably get more responses in a different Forum. Maybe Astrophysics.

I disagree, a possible explanation might be the eroding of atmospheres due to cometary impacts increased in ferocity by Jupiter's gravitational field. Ganymede is mostly ice and silicates as well as Callisto and Titan.

 

[Saturn V]

I've just spent 30 minutes reading through this lot and I really wish I hadn't.

Quantimez, you clearly don't understand the basics of the maths and concepts behind simple issues (such as sunlight and atmospheric conditions) and yet you are making wild claims regarding energy and compositional makeup of these bodies.

You also don't appear to have a solid understanding of the economic side of things and are again making rather wild and extremely speculative claims regarding the justifications for such tasks (terraforming).

I agree. Though he dosen't seem to understand the basics of math and the economic issues. He's hit quite a few hard points that need to be explored. There is stark difference between Titan and Ganymede despite their similar compositions "Gravitation" and the cleshay mainstream assumption of gravity. It was "ALOT" of reading. Nice try nonetheless.

 

[Saturn V]

All these worlds are yours except Europa. Attempt no landings there.

I've wondered about that... Where did that come from?

 

[Saturn V]

You provided good points in many areas, and you are very right in so many points. Though one underlining theme may present itself as it does today. Economically speaking cost. Also not meaning to appear pessimistic. You would have to operate carefully in a vacuum and every member working there would need protection against a variety of things while the construct these things factoring in tourism. Titan was used as an example that though it had low G relatively small size and mass its components could exist in those tmperatues in some form(Nitrogen, methane, ethane etc.) Though water vapor and CO2 would not. These are green house gases to Earth's atmosphere trapping heat. Your right Titan gets minimal light. Though Jupiter being estimated 5.2 AU Ganymede may receive just enough heat and warmth 19% of Earth. You would just have to keep it "lit" from refreezing then implying more green house gases. Perhaps after global thermonuclear detonations. You can still use solar panels at that distance and comets become active and at that distance as well underlining the possibility. The Earth's atmosphere has less than 1% of CO2 and perhaps other trace green housegases and see what it has done?!? Once oxygen splits from hydrogen in the vast amounts of water ice on ganymede. Then vaporize naturally (O3 ozone) from radiation as easily as it forms from ionizing electrical arcs on earth. Now a vacuum makes sense for space travel but in a sense of priority of pace tourism and manufacture it seems easier and a bit more cost effective to have an Earth like biosphere for relaxation looking up into the jovian sky and for working on building those materials needed further out as a refreshing nostalgic waystation. The gravity would be similar to the moon already imagine how easy would(hypothetically) for the apollo astronauts without those"bulky but light already in lunar gravitation). As landing on the moon was a fearfully but time consuming maybe and maybe not but it was indeed possible. We came from figuring out how to get into orbit toward the moon in 8 years factoring in cost. Optimistically speaking, we don't know until we try it's a maybe so or maybe not. The impossibles of yesterday are proving possible today. Mars has water ice? Short liquid flows? Before it was thought only CO2 ice existed and it's GRAV was to low to hold a thick atmosphere and a no magnetic field. Venus has no magnetic field look at it's atmosphere! Those assumptions indeed contradicted what exists in our solar system. In all confidence may I imply that its highly beneficial to terraform at minimum Mars and a moon in the Jovian system Ganymede to make to bring things from home to makes the voyage more comfortable and reasuring. Nothing great ever strived and worked for was easy. There's nothing like a blue sky for the heart.

You forgot to add wator vapor, though it is a variable it still counts as a greenhouse gas. Indeed water vapor plays a big role in the system so water vapor and CO2 may go hand in hand for Earth's atmosphere and keeping it stable.

 

[Quantimez]

What precisely in its composition makes you think it could build the sort of thick nitrogen atmosphere you'd need? You're looking for an Earth-atmosphere-mass of nitrogen in something that's mostly rock and water. There might be some ammonia there, but its presence is mostly speculation. "far greater abundance than required" of what, and how do you know this?




That's not logic, it's just bad math. You don't get to simplify inverse square falloff to simple inverse falloff...that certainly isn't going to "diminish the likelyhood of error". Mars is about 1.5 times Earth's distance from the sun (not "a little more than twice"), which does work out to very close to 1/2 the sunlight per unit area. Venus, at about 0.7 AU, gets twice the sunlight. Jupiter and its moons are 5-5.5 times the distance, which means it gets 1/25-1/30th...as I've said multiple times, 3-4%. For Jupiter, not Saturn...once again, Saturn and its moons would get around 1% of what Earth does...which is why Titan's cold enough to retain its atmosphere, despite having one full of methane and other greenhouse gases. Your estimates of the difficulty involved are wildly off because you're not even using the right scaling laws.

This is ignoring what would be blocked by the thousand-km-deep atmosphere you'd need to have Earthlike pressures at the surface, and you've said nothing about how you'll get around the issue of atmospheric loss. You can't just ignore inconvenient problems.

Well, as you implied about the inverse-square law. Solar radiation propagates with distance. I apologize for my silly error I was counting point to point light not the propagating dispersing radiation. (Note: Solar wind is a form of radiation decreasing also). For instance, from the Mercury(9140 watts per sq meter) to Earth(1370 watts per sq meter. Of course a threefold increase of distance would result in a ninefold decrease in radiation. This would only leave Mars as the terraforming candidate.

 

[Quantimez]

You forgot to add wator vapor, though it is a variable it still counts as a greenhouse gas. Indeed water vapor plays a big role in the system so water vapor and CO2 may go hand in hand for Earth's atmosphere and keeping it stable.

Thank you

 

[Quantimez]

I've just spent 30 minutes reading through this lot and I really wish I hadn't.

Quantimez, you clearly don't understand the basics of the maths and concepts behind simple issues (such as sunlight and atmospheric conditions) and yet you are making wild claims regarding energy and compositional makeup of these bodies.

You also don't appear to have a solid understanding of the economic side of things and are again making rather wild and extremely speculative claims regarding the justifications for such tasks (terraforming).

The compositional makeup of Ganymede, Callisto and Titan are indeed mostly rock and ice. Economics change, this does not imply today but the far future when these ventures might be more feasible for mankind. So in that regard its sound to make educated guesses on what may be available in the distant and not foreseeable future based of progress made in the last 100 years. In that regard it would be understandble to speculate to that degree. I made an error concerning the inverse square law not imputing it in terms of outward dispersing weakening energy and seeing it as point to point.

 

[Jon Richfield]

Is terraforming an answer to anything?

That is a rather curious question, isn't it? What is it an answer to? What sort of answer would you regard as constructive? Would mental stimulation count as an answer in the sense you have in mind? Do you mean: "Is it useful for anything?"? Does my thread "Venus for Termites" supply any useful answer?

 

[qraal]

If we're talking about Terraforming in the broader sense of increasing habitats for life then this recent paper is worth considering...

Hydrogen Greenhouse Planets Beyond the Habitable Zone

Raymond Pierrehumbert, Eric Gaidos
(Submitted on 29 Apr 2011)
We show that collision-induced absorption allows molecular hydrogen to act as an incondensible greenhouse gas, and that bars or tens of bars of primordial H2-He mixtures can maintain surface temperatures above the freezing point of water well beyond the "classical" habitable zone defined for CO2 greenhouse atmospheres. Using a 1-D radiative-convective model we find that 40 bars of pure H2 on a 3 Earth-mass planet can maintain a surface temperature of 280K out to 1.5AU from an early-type M dwarf star and 10 AU from a G-type star. Neglecting the effects of clouds and of gaseous absorbers besides H2, the flux at the surface would be sufficient for photosynthesis by cyanobacteria (in the G star case) or anoxygenic phototrophs (in the M star case). We argue that primordial atmospheres of one to several hundred bars of H2-He are possible, and use a model of hydrogen escape to show that such atmospheres are likely to persist further than 1.5 AU from M stars, and 2 AU from G stars, assuming these planets have protecting magnetic fields. We predict that the microlensing planet OGLE-05-390L could have retained a H2-He atmosphere and be habitable at ~2.6 AU from its host M star.

...from http://arxiv.org/abs/1105.0021" . Assuming hydrogen loving organisms are biochemically feasible, then Life's domain might be extended out to Saturn.

 

[qraal]

To tie this discussion to engineering let's look at the physical requirements of the task of providing Ganymede with 10 bars of hydrogen atmosphere. The radius is 2634.1 km and surface gravity is 1.428 m/s², letting us compute the total mass of atmosphere as 6.1E+19 kg. Sourcing that much hydrogen from the gas giants will be challenging, but not ludicrous in the context of a solar system wide economy. Of course we're a long way from that point as yet.

The question for would be terraformers of the gas giant Moons is just what to do about the ice? The outer Galileans and Titan are half ice, implying very deep oceans if they fully melted. The obvious answer is to keep their average temperature sub-glacial, but then the Moons aren't much better than the Antarctic ice-caps as habitats and a lot further away.

 

[cjameshuff]

To tie this discussion to engineering let's look at the physical requirements of the task of providing Ganymede with 10 bars of hydrogen atmosphere. The radius is 2634.1 km and surface gravity is 1.428 m/s², letting us compute the total mass of atmosphere as 6.1E+19 kg. Sourcing that much hydrogen from the gas giants will be challenging, but not ludicrous in the context of a solar system wide economy. Of course we're a long way from that point as yet.

The question for would be terraformers of the gas giant Moons is just what to do about the ice? The outer Galileans and Titan are half ice, implying very deep oceans if they fully melted. The obvious answer is to keep their average temperature sub-glacial, but then the Moons aren't much better than the Antarctic ice-caps as habitats and a lot further away.

You're nowhere near to the point where the ice can become a problem.

Your assumption that the entire mass of the atmosphere would be subject to the surface gravity of the moon is wildly wrong. The more you pile on, the further out of the gravity well it extends and the less the atmosphere you're piling on contributes to the surface pressure. Titan, with very similar size and surface gravity, has an atmosphere of nitrogen (about 14 times the density of hydrogen at a given temperature and pressure), with "only" 1.47 bar of surface pressure. That atmosphere extends out a thousand km from the surface, at its current frigid temperatures. It's not just a matter of piling more atmosphere on...what do you suppose happens when the molecules of your upper atmosphere are moving at greater than escape velocity at that altitude? We're not talking the tail of the velocity distribution, either, but the main body...there's just no way you're getting a deep, dense, warm atmosphere to stick to such a low-mass object. The quoted paper referred to a super-earth three times the mass of the largest terrestrial planet in our solar system, not a tiny moon!

 

[qraal]

You're nowhere near to the point where the ice can become a problem.

Your assumption that the entire mass of the atmosphere would be subject to the surface gravity of the moon is wildly wrong. The more you pile on, the further out of the gravity well it extends and the less the atmosphere you're piling on contributes to the surface pressure.

I am well aware of the issue. Rather than being over-enthusiastic but maths challenged, like some who suggested these things, I have modeled the atmosphere to some extent. You do realize that the region inside the Roche lobes of the Ganymede-Jupiter system is under control of Ganymede's gravity don't you? The atmosphere could extend out a very long way, albeit very diffusely. But most of it is relatively close to the surface, surprisingly.

However I have probably neglected UV energy input into the stratosphere a bit too much. And I can't pin down just how high the exobase is, so my model is probably too simple. A hydrogen atmosphere is probably unstable, but I haven't definitely ruled it out yet. A Mars to Earth mass object might hold on to it for sufficient periods of time.