Ability for Human Life on Other Planets

[apollo2011]

Hi Everyone!

 

I have been studying the Solar System in my Science class and particularly the gas giants. I just wanted some clarification. Aside from today's limited ability for us travel to another planet and live there, because of limited oxygen, etc. Would it be possible to live on a gas giant?

 

The project we have been working on was basically a presentation in the future persuading people to move to another planet. The would take place so far in the future that transportation and necessities of life would all no longer be an issue.

 

From my previous knowledge, I would have thought that the only planets that could actually sustain Human life in the future would be Mercury, Venus, Mars, and of cource, Earth. However, we were allowed to choose all the gas giant planets. One thought I had was that it was possible to live above the surface (even though today creating an airborne civilization would be impossible).

 

So I just wanted some clarification on the ability to sustain life on other planets and the actual amount of fact the project is based on.

[[Tycho?]]

Uh, living on the gas giants would probably not be a good idea. Even for an airborne habitat, gas giants usually have huge wind currents. It would be a lot easier just to live on one of the moons of said planet.

[ydoaPs]

gas giant have no real surface to speak of. the pressures would surely make the mission fail.

[Martin]

Would it be possible to live on a gas giant?

 

The project we have been working on was basically a presentation in the future persuading people to move to another planet. The would take place so far in the future that transportation and necessities of life would all no longer be an issue.

 

... However' date=' we were allowed to choose all the gas giant planets. One thought I had was that it was possible to live above the surface (even though today creating an airborne civilization would be impossible).

 

...[/quote']

 

It would be quite possible for humans to live in caverns hollowed out

in the ice on several of the moons of Jupiter. It might be rather attractive.

 

I dont think it would not be practical to try to live in Jupiter's atmosphere itself because of the strong gravity and the intense radiation.

 

Several of the moons (europa, ganymede, callisto) have layers of water ice at the surface which are estimated to be several kilometers thick, in some cases as much as 100 kilometers thick. the ice is mixed with minerals. on europa especially there is believed to be liquid water under the ice

 

Look up Europa on google, lots of sites describe the conditions there.

 

the point about ice on a low-gravity moon is this: you have some kind of power plant (it is in the future, maybe you have a clean nuclear reactor, I dont know) that makes electricity and heat----you melt a tunnel down into the ice----you close the entrance so that air won't escape-----you hollow out rooms----you electrolyze water to make a breathable atmosphere----if you like you can make a big stadium-size central hall filled with breatable atmosphere and it could have a lake of water, with fish.

 

in the gravity of a Jupiter moon things would weigh less, so you could do human-powered flight very easily in a large central cavern----humanpowered flight is just barely possible on earth with big awkward wings and an athlete pedaling furiously to turn the prop.----on Callisto anybody could do it, easy pedalling and smaller more graceful aircraft.

It would be fun.

 

the ice halls could be beautiful

 

if there was a large colony there could be horizontal tunnels to get from one community to another and you could ice-skate----the transportation network could, in effect, be an extended long skating rink.

 

the important thing is always to have a lot of cheap electricity to keep

the ice habitat cheerfully lit and warm enough so there would be ponds of water forming in many places, where algae would grow to feed the fish.

 

the pond water would be near-freezing like in arctic, but fish can cope with that all right (plenty of species thrive in arctic water as long as light and nutrients are right)

 

the habitat could be hollowed out deep enough below the surface so as to be safe from the surface vacuum, the surface cold, breakage by meteorite-hits, blowouts, radiation etc.

 

remember that Jupiter has a strong magnetic field that traps a lot of radiation and even in as close as the satellite Io it would be dangerous to live because of that (Io is a bad place anyway, volcanoes etc, too warm for ice). that is why the further out moons like Ganymede and Callisto might be better----no worry about radiation

 

when you occasionally put on a suit and went up to the surface for sightsee there would be this huge planet Jupiter in the sky, and other moons

 

the large ice-covered Jupiter moons would be a lot easier and more fun to live on than (for example) Mars. Mars is too dry and there is nothing immediately available to make a house out of. The ice at the poles is not very thick and probably not structurally solid enough---it changes seasonally which is bad news---and it is a mix of CO2 ice and water ice.

I would not trust it.

 

I would not want to live anywhere that didnt have a lot of H2O, the colony could get dehydrated which would be a real shame.

 

so I suggest you make sure that the teacher accepts that "living on planets" also includes the idea of "living on the satellites (moons) of those planets" as well. it would make the project more interesting to consider that possibility as well

[VendingMenace]

yeah, i think the other posters have covered it nicely. The largest problems would most likely be; increadibly high pressures, horrible weather, and decently high gravity. At least that would be my thoughts.

 

Though i thought that gas giants HAD surfaces. Am i just totally off base here. I thought they had a solid core surrounded by a gasseous layer?

[Nalos Surith]

From what we know, none of the gas giants have a current core and are primarily just made up of atmospheric gas.

[Martin]

yeah' date=' i think the other posters have covered it nicely. The largest problems would most likely be; increadibly high pressures, horrible weather, and decently high gravity. At least that would be my thoughts.

 

Though i thought that gas giants HAD surfaces. Am i just totally off base here. I thought they had a solid core surrounded by a gasseous layer?[/quote']

 

maybe Jupiter has a solid layer if you go deep enough

but deep down in the atmosphere the pressure (and temperature) would be enormous, so any kind of life that I can imagine would want to be floating in the atmosphere----high enough to be out of the worst pressure and temp.

 

it wouldnt be human, or any terretrial type, I guess.

it would be some life form that had evolved to living in

gas giant atmosphere

[Alexa]

From my previous knowledge, I would have thought that the only planets that could actually sustain Human life in the future would be Mercury, Venus, Mars, and of cource, Earth. However, we were allowed to choose all the gas giant planets. One thought I had was that it was possible to live above the surface (even though today creating an airborne civilization would be impossible).

A demontration of possible life would be easier on Mars. So I guess you weren't lucky with the choice. Let's we what we have available : Jupiter, Saturn, Uranus and Neptune (the Jovian planets)

 

I'll begin with what we know about their surface and atmosphere. I'm sure you know already all about it, but in my humble opinion, it will be easier to find a solution after a short revision.

1. Jupiter is the fifth planet from the Sun and is the largest one in the solar system. If Jupiter were hollow, more than one thousand Earths could fit inside. It also contains more matter than all of the other planets combined. It has a mass of 1.9 x 1027 kg and is 142,800 kilometers across the equator. The atmosphere is very deep, perhaps comprising the whole planet, and is somewhat like the Sun. It is composed mainly of hydrogen and helium, with small amounts of methane, ammonia, water vapour and other compounds. At great depths within Jupiter, the pressure is so great that the hydrogen atoms are broken up and the electrons are freed so that the resulting atoms consist of bare protons. This produces a state in which the hydrogen becomes metallic.

Colourful latitudinal bands, atmospheric clouds and storms illustrate Jupiter's dynamic weather systems. The cloud patterns change within hours or days. The Great Red Spot is a complex storm moving in a counter-clockwise direction. At the outer edge, material appears to rotate in four to six days; near the center, motions are small and nearly random in direction. An array of other smaller storms and eddies can be found through out the banded clouds. Auroral emissions, similar to Earth's northern lights, were observed in the polar regions of Jupiter. The auroral emissions appear to be related to material from Io that spirals along magnetic field lines to fall into Jupiter's atmosphere. Cloud-top lightning bolts, similar to superbolts in Earth's high atmosphere, were also observed.

2. Saturn is the sixth planet from the Sun and is the second largest in the solar system with an equatorial diameter of 119,300 kilometres. Much of what is known about the planet is due to the Voyager explorations in 1980-81. Saturn is visibly flattened at the poles, a result of the very fast rotation of the planet on its axis. Its day is 10 hours, 39 minutes long, and it takes 29.5 Earth years to revolve about the Sun. The atmosphere is primarily composed of hydrogen with small amounts of helium and methane. Saturn is the only planet less dense than water (about 30 percent less). In the unlikely event that a large enough ocean could be found, Saturn would float in it. Saturn's hazy yellow hue is marked by broad atmospheric banding similar to, but fainter than, that found on Jupiter. The wind blows at high speeds on Saturn. Near the equator, it reaches velocities of 500 meters a second. The wind blows mostly in an easterly direction. The strongest winds are found near the equator and velocity falls off uniformly at higher latitudes. At latitudes greater than 35 degrees, winds alternate east and west as latitude increases.

 

3. Uranus is the seventh planet from the Sun and is the third largest in the solar system. It has an equatorial diameter of 51,800 kilometres and orbits the Sun once every 84.01 Earth years. It has a mean distance from the Sun of 2.87 billion kilometres. The length of a day on Uranus is 17 hours 14 minutes. The atmosphere of Uranus is composed of 83% hydrogen, 15% helium, 2% methane and small amounts of acetylene and other hydrocarbons. Methane in the upper atmosphere absorbs red light, giving Uranus its blue-green color. The atmosphere is arranged into clouds running at constant latitudes, similar to the orientation of the more vivid latitudinal bands seen on Jupiter and Saturn. Winds at mid-latitudes on Uranus blow in the direction of the planet's rotation. These winds blow at velocities of 40 to 160 meters per second. Radio science experiments found winds of about 100 meters per second blowing in the opposite direction at the equator.

 

4. Neptune is the outermost planet of the gas giants. It has an equatorial diameter of 49,500 kilometres. If Neptune were hollow, it could contain nearly 60 Earths. Neptune orbits the Sun every 165 years. A day on Neptune is 16 hours and 6.7 minutes.

The first two thirds of Neptune is composed of a mixture of molten rock, water, liquid ammonia and methane. The outer third is a mixture of heated gases comprised of hydrogen, helium, water and methane. Methane gives Neptune its blue cloud color.

Neptune is a dynamic planet with several large, dark spots reminiscent of Jupiter's hurricane-like storms. The largest spot, known as the Great Dark Spot, is about the size of the earth and is similar to the Great Red Spot on Jupiter. Voyager revealed a small, irregularly shaped, eastward-moving cloud scooting around Neptune every 16 hours or so. This scooter as it has been dubbed could be a plume rising above a deeper cloud deck.

Long bright clouds, similar to cirrus clouds on Earth, were seen high in Neptune's atmosphere. At low northern latitudes, Voyager captured images of cloud streaks casting their shadows on cloud decks below.

The strongest winds on any planet were measured on Neptune. Most of the winds there blow westward, opposite to the rotation of the planet. Near the Great Dark Spot, winds blow up to 2,000 kilometres an hour.

I'll take Neptune and try to prove a civilization under water. Not a human one, of course. Anyway, if you have to show some pictures, the blue color would be nice.

I hope this can help you.

[Skye]

Alexa, you should cite where you find stuff.

[Alexa]

I would like to give the souce, but unfortunately I've saved that stuff in a word document without refference to the link. If I can remember it soon enough, I'll write it in another post. Sorry. The initial info was for my knowlegde only.

[Gilded]

Heh, the gas giants are nice in the aspect that they might have diamonds raining from the upper layers.

 

"on europa especially there is believed to be liquid water under the ice"

 

Europa has a nasty cover of sulfuric acid from the sulfur ions coming from Io. You could use the H2SO4 to make batteries or something fun though. Luckily, it doesn't cover the whole moon.

[Cap'n Refsmmat]

Alexa, you should cite where you find stuff.

Try googling it.

www.solarviews.com

That's where it came from.

[ydoaPs]

o, gas giants may have liquid cores due to pressure

[Playmaker03]

Just a quick point. Why should anyone "cite" when they find information, it is so easy to find such basic info like that posted about the outer most planets.

 

Within ten minutes of searching on a search engine you could find all the ifo posted and much more!

[Sayonara]

Just a quick point. Why should anyone "cite" when they find information, it is so easy to find such basic info like that posted about the outer most planets.

Firstly, if you copy a block of someone else's information and do not reference where it came from, most academics will consider this plagiarism (whether that's what you intended or not).

 

Secondly it allows your peers to follow up the citation and get an idea of how good the source is (as an example of why this is still ueful on the web, put the exact phrase "the Earth is flat" into google).

[[Tycho?]]

From what we know, none of the gas giants have a current core and are primarily just made up of atmospheric gas.

 

No. The gas giants are beleived to have a core. Jupiter for example is believed to have a core comprised of metallic hydrogen, as a result of the huge pressures, as well as rock.

 

 

Planetary composition

 

Jupiter is composed of a relatively small rocky core, surrounded by metallic hydrogen, surrounded by liquid hydrogen, which is surrounded by gaseous hydrogen. There is no clear boundary or surface between these different phases of hydrogen; the conditions blend smoothly from gas to liquid as one descends.

 

http://en.wikipedia.org/wiki/Jupiter_%28planet%29

[ydoaPs]

']No. The gas giants are beleived to have a core. Jupiter for example is believed to have a core comprised of metallic hydrogen' date=' as a result of the huge pressures, as well as rock.

 

 

 

 

http://en.wikipedia.org/wiki/Jupiter_%28planet%29[/quote']

 

what do you mean "metallic" hydrogen? isn't all hydrogen metallic?

 

edit: "the earth is flat" got 2,300,000 results

[VendingMenace]

what do you mean "metallic" hydrogen? isn't all hydrogen metallic?

 

Well, that is a good question.

 

Hydrogen is typically in its gas phase when you encounter it. As such, it doesn't really display the properties that metals have (ie. shiny, malleable, ductile, heat conducting, electrically conducting, ect.) As such, it is rarely reffered to as a metal.

 

However, if one was to compress it (or cool it) enough, then it would condense and start to display these properties (at least the electronically conductive one -- kinda hard to see if the small short lived samples made so far are shiny ). As such, the term "metallic hydrogen" is commonly used to refer to hydrogen when it is in its solid state.

 

 

For more information, the wikipedia is always a decent choice

http://en.wikipedia.org/wiki/Metallic_hydrogen

[Martin]

However' date=' if one was to compress it [b'](or cool it)[/b] enough, then it would condense and start to display ... As such, the term "metallic hydrogen" is commonly used to refer to hydrogen when it is in its solid state.

...

 

I disagree with your statement that metallic hydrogen means solid hydrogen.

 

You can have solid hydrogen that is not metallic.

 

I also think one can have metallic hydrogen that is not solid (metallic and solid do not mean the same thing)

 

I disagree with your saying "OR cool it" because I do not think cooling is enough to make hydrogen metallic. I think you always need to compress it--- to get the nuclei close enough together that the electron wave functions become no longer localized around a single nucleus or a few nuclei.

 

In a large piece of metal, some of the the electron wave functions are macroscopic in size----similar in size to the sample itself---engulfing many nuclei.

 

This is what characterizes a metal. It also causes the metal's low electrical resistance.

 

something can be liquid and still be a metal----may still be shiny and have low electrical resistance---if the wavefunctions surround many nuclei.

 

when metallic hydrogen is made experimentally, the test for whether it has become metallic is nothing other than a large drop in conductivity (signifying that bit about the wavefunctions). one does not worry about solid or liquid because that is not the issue---metallic is not about that

[VendingMenace]

You can have solid hydrogen that is not metallic.

 

Intersting point. Do you know of any experiments in which people belived that they made solid hydrogen and it was not metallic? That would be interesting to read about. (i know very little about this expect for what i remember reading in HS)

 

I also think one can have metallic hydrogen that is not solid (metallic and solid do not mean the same thing)

 

True. I am afraid that was bad writting on my part. Obviously' date=' you can have a liquid metal (ie. the obvious, mercury). I just thought that most of the experiments that had been done, people thought they made the solid state of hydrogen. But i could be wrong here too, i suppose (most likely).

 

I disagree with your saying "OR cool it" because I do not think cooling is enough to make hydrogen metallic.

 

Again, perhaps my understanding may be incomplete, i thought it was theoretically possible to cool hydrogen enough so that metalic propreties emerged. But i could have just misunderstood the explination that i was given at the time :/

 

I think you always need to compress it--- to get the nuclei close enough together that the electron wave functions become no longer localized around a single nucleus or a few nuclei.

 

In a large piece of metal, some of the the electron wave functions are macroscopic in size----similar in size to the sample itself---engulfing many nuclei.

 

I am afraid that i do not quite understand what you are saying...

It seems that the electron wavefuctions yeild a probability density that ALWAYS yeilds an area that is macroscopic -- in the sense that there is some probablility that an electron in your computer could be on the moon. The problem is that this would be extremely unlikely.

 

What i thought happens in metals is that the electrons in the conduction band are delocalized over large areas and hence are free to move about the metal. This leads to the metalic properties of conduction and luster (caused by the surface plasmon), ect.

 

So, it seems that all that is required is for the activation energy for electron transfer across the substance ---> 0 for the substance to be a metal. Is this correct?

 

Now of course this will cause the electron to be able to be described by a wavefunction which has a probability density which remains significant over large volumes of the metal, but really it is this small activation energy for electron tranfer that is the root cause of metal. Would you agree? And the wavefunction is just a convienent way of talking about the effect that this low activation energy has on the electrons within the substance.

 

Or is this all, crap? Feel free to tell me why. I am not really a physisist. I am kinda flying by the seat of my pants, so i would welcome some enlightenment on the subject

 

something can be liquid and still be a metal----may still be shiny and have low electrical resistance---if the wavefunctions surround many nuclei.

 

Here, i mispoke again. SOrry. I meant to say luster -- which is a product of the surface plasmon (if i remember right) and, hence, is a property of metals.

 

when metallic hydrogen is made experimentally, the test for whether it has become metallic is nothing other than a large drop in conductivity (signifying that bit about the wavefunctions). one does not worry about solid or liquid because that is not the issue---metallic is not about that

 

 

Ok, so people don't really know whether it is solid or liquid then? Or do they have a guess?? And i am assuming that you ment a large drop in RESISTANCE and an increase in CONDUCTIVITY, right? I think that would make more sense. Or am i completely way off base here?

 

 

 

Anyways, thanks for your reply above -- always good to have people to keep you honest when you are lazy and to point out where you are wrong. ANd if you could correct me here where i am in error in my thinking that would be most welcome, thank you.

 

[Martin]

And i am assuming that you ment a large drop in RESISTANCE and an increase in CONDUCTIVITY' date=' right? I think that would make more sense. Or am i completely way off base here?

 

[/quote']

 

You are right! I misspoke. I meant a large drop in resistance. that is what they found in the hydrogen, at the moment they applied those very high pressures. it is the test of having achieved metallicity

 

everything you said just now seemed right to me, but it would be good if you got swantsont (a local expert) to check out any remaining questions since I cant speak from authority.

 

I couldnt study every point in your post but it seems the main thing still unresolved is whether there can be hydrogen that is frozen solid (say at ordinary atmospheric pressure) but not metallic.

 

I will have to check the freezing point of hydrogen, or learn some more about its phase diagram.

right now I only speak from memory----I think I did read, some years back, that hydrogen has a solid phase that is nonmetallic

(metallic, AFAIK, takes huge pressure). I will double check this and get back to this thread tomorrow.

 

regards,

Martin

[ydoaPs]

so, state of matter can change an element from metal to nonmetal?