PDA

View Full Version : terraforming venus



damienpaul
2003-Dec-26, 03:08 AM
Just a silly question, how would we go about terraformingn Venus for human habitation?

Fraser
2003-Dec-26, 04:03 AM
I'm not sure. But I used to have this old PC game called SimLife where one of the scenarios was to terraform Venus and Mars. Mars was relatively straightforward... Venus was HARD.

Josh
2003-Dec-26, 04:11 AM
So what you're saying is we have to take your old PC to venus?

damienpaul
2003-Dec-26, 04:14 AM
I have played that simulation also, i used it once in my class - yes, it is very hard! but we managed to get a planet with 65% water and an average temperature of 31 degrees celsius

B_Sirius
2003-Dec-26, 06:49 AM
Hmmm...sounds like we are all suffering from "Venus Envy" B)

Sorry...I know that was bad but I haven't had much sleep for several days now and I can't always be held accountable for my actions.

But anyway, I seem to remember from my basic astronomy knowledge that Venus is constantly shrouded in clouds that are raining very caustic acid rain down and the temperature on Venus is essentially incompatible with human life. Whatever means we would have for "terraforming" would have to be done remotely...I don't see us landing on Venus or building a base there.

It's definitely in the realm of science fiction at the moment. Or maybe the screenplay writers for "Star Trek: The search for Spock" could give us some insight. The screenplay writers for "Total Recall" already have Mars figured out.

damienpaul
2003-Dec-26, 10:01 AM
i read somewhere and in my 27 yr old age i cannot remember where exactly, that if we slam a whole lotta comets into venus then that may do the trick

kashi
2003-Dec-26, 10:07 AM
I believe the game was called SimEarth, not SimLife. A great game. I used to find venus more fun than mars.

damienpaul
2003-Dec-26, 10:13 AM
and a hell of a lot more challenging...were you able to terraform venus?

GOURDHEAD
2003-Dec-26, 03:05 PM
We may have already inadvertantly begun the terraforming of Venus by having deposited earth microbes there in some of our past missions.

We must use bio-engines to do the work in a hundred years or so that it took microbes 3 billion years to do here. At the Venusian altitude where the presure is about one atmosphere, the temperture is near the freezing point of water on earth and sulfuric acid is prevalent. As the altitude decreases, the temperature and pressure increase. On earth we have acid loving microbes and heat loving microbes. We already know how to modify them to combine features to our advantage. This suggests using microbial psychrophilic acidophiles (euplotes antarcticus, polaromonas vacuolata, etc.,) genetically modified, if and to the extent required, to break down the high altitude cold sulfuric acid clouds and barophilic hyperthermophiles [e.g., methanopyrus kandlerii, pyrolobus fumarii, etc., ] to break down the lower altitude hot CO2 respectively.

Some strain of bacteria (either staphococcus or streptococcus) inadertantly deposited on the moon, without special protection, survived for several years in a viable state. Compared to the moon the upper atmosphere of Venus is a piece of cake (I hope not yellow cake). :ph34r:

Once we (now we includes our microbes as respectable earthlings) dispel the greenhouse effect of the sulfuric acid clouds thereby reorganizing the hydrogen, carbon, and oxygen into molecules more to our liking, we will be well on our way.

Does anyone know how to compute the depth of water that may result including how much would wind up in silicates, iron sulphates, calcites, and calcates? If push comes to shove we can install "venusian blinds" in orbit about Venus to get the temperature down by reflecting solar heat away from Venus. (See my topic on Interstellar Transportation for more detail on a system needed to perform this task.) ;)

VanderL
2003-Dec-26, 03:20 PM
Hmm, it would be something of a wonder when we dumped the exact type of bacterial strain into the Venusian atmosphere. The biggest problem to me seems the enormous heat on Venus' surface; I don't buy the runaway greenhouse effect that is thought to cause all the heat, so it would need a lot more than changing the content of the Venusian atmosphere.

kashi
2003-Dec-27, 04:58 AM
Yeah I was able to terraform venus in that game.

g3wzr
2003-Dec-27, 11:52 AM
To terrform Venus, you need to take the really long view, because, even if you could dump enough water on it (by dropping icy bodies collected from the Kuyper Belt, say) to give any kind of life a chance, there is the time taken for the surface to cool from its present 450C, or thereabouts to 20C, say. A colleague of mine who has better maths than me calculated that time - it is around 1 million years. Long time to wait, huh?

GOURDHEAD
2003-Dec-27, 02:09 PM
We won't need to bring in water from outside Venus. The microbes will do the job for us using the hydrogen and oxygen already there. The danger is that we may get too much water (e.g., water world). As for cooling the planet down, we'll have to get a little smarter about heat exchanging technology and slide the schedule from 100 to 200 years. Come on! let's think positive! If it takes 10^6 years....well let's do it anyway. ;)

Sing the paranoid's anthem. :ph34r:

The universe is out to get us;
We have to get smart fast.
Learn by doing including the fuss;
Otherwise we'll be left in the past.
And if it proves to be a joke played by God,
Cheer up! He's still a good Sod.
:D :D :D :D :D :D :D

Hydrok
2003-Dec-27, 04:11 PM
Does anyone else think that we are nuts for even attempting terraform, think about this: Humans can only exist when they have all their nessesities met. What is the one thing that every human needs to survive; the one thing that we have been looking for all over the solar system? Liquid water. But what property of water makes it so hard to find? How about the VERY NARROW phase zone? the difference is only 100 C between ice and gas. now compare those differences to the two closest planets to us. Venus is always hotter than 100 C and Mars is always colder than 0 C. So how do you think we should cool venus down and warm mars up. Answer that and i think you might have something.

TheThorn
2003-Dec-27, 04:14 PM
Terraforming means setting up a balanced, stable ecology that can support humans. That's more than just an oxygen atmosphere. And the key word is "stable". Getting there from where Venus is now, if possible (and I think it likely IS possible) will involve a HUGE transient that will no doubt take a long long time to damp out. Not just the heat ether, but all the biological transients. Think about the unforeseen consequences of introducing, oh, say, rabits to Austrailia, or Zebra Mussels to Lake Erie. Multiply it a million fold.

As it stands, parts of Venus' atmosphere might support some carefully engineered species of Earth life. The trick is to put the right types of life there that would fill that niche, and modify part of the rest of the atmosphere to make it hospitable to some other forms of earth life so that we could introduce them and they'd fill THAT niche and modify other parts of Venus' environment and so on. It will be an iterateive process that will be filled with unforeseen effects and will take a long, long time.

So far, we haven't shown even the smallest understanding of all the interactions that are going on inside a stable ecology, much less how to create one from such nasty initial conditions.

Meanwhile, while the long, long process of terraforming Venus is going on, we also have to concentrate on avoiding UN-terraforming Terra (which is much more likely to happen, the way we are going now).

Planetwatcher
2003-Dec-28, 03:48 AM
I think we'd have to start by getting Venus about 15 million miles farther from the Sun. Then add water, and keep a good cloud cover which isn't deadly to humans.

victor sekulov
2003-Dec-28, 03:58 AM
I read an article by Carl Sagan where he went into detail about how you can make it rain in hell (ie Venus). Goes into detail about how to terraform Venus. Check out his book - Cosmos for more details.


cheers

kashi
2003-Dec-28, 04:02 AM
I think we'd have to start by getting Venus about 15 million miles farther from the Sun. Then add water, and keep a good cloud cover which isn't deadly to humans.

We could lasso it and pull it out (pulling us IN in the process).

Guest
2003-Dec-29, 03:58 PM
Originally posted by GOURDHEAD@Dec 26 2003, 03:05 PM
Some strain of bacteria (either staphococcus or streptococcus) inadertantly deposited on the moon, without special protection, survived for several years in a viable state.

Since we have never returned to a prievious landing site, how do you suppose this fact was learned?

GOURDHEAD
2003-Dec-29, 07:25 PM
Unless my memory has betrayed me, one of the Appollo crews landed near a site previously visited by an unmanned craft and collected a sample of some sort which to their surprize turned out to include viable bacteria. I assume appropriate handling procedures were practiced and that confidence in the source of the bacteria was accurate. Sorry I can't provide a web reference.

TheThorn
2003-Dec-29, 09:00 PM
Hi Gourdhead.

Try this site:Apollo 12 Surveyor III Analysis (http://www.lpi.usra.edu/expmoon/Apollo12/A12_Experiments_III.html)

Sounds like there is some question over whether the Streptococcus mitis they found was a passenger in the camera on Surveyor, and spent 31 months on the moon unprotected, or whether it was contamination during the testing afterwards. 33 samples were tested for batcteria, only one came up positive.

John M. Burt
2003-Dec-30, 06:22 AM
Well, if we seed the Venusian atmosphere with the right microbes, and they produce an atmosphere where there's more oxygen and water vapor and less sulphuric acid, and the greenhouse effect is greatly reduced so that the surface temperature drops enough that the water can fall to the surface in the proverbial Big Rain, there's still the difficulty of a surface atmosphere 90 times denser than Earth's. Tricky.

We might have to import cometary materials after all -- not to supply extra water (although IIRC, Venus only has about 100cm of precipitable water) but to provide the hydrogen, nitrogen, &c. to bind the excess carbon and oxygen.

GOURDHEAD
2003-Dec-30, 01:26 PM
The Thorn:
Thanks for the reference. Looks like Streptococcus mitis isn't so tough after all. The good news is that a pathogen is not as tough as I thought. The bad news is that it may be more difficult than I thought to engineer microbes to do the teraforming. Maybe some combination of deinococcus radiodurans and strain 121 will bail me out.

John M. Burt:
It will be tricky indeed to get rid of 90 atmospheres pressure. I have assumed that once a few thousand feet of water (additional water from the shuffling of C,O,S, and H) have accumulated on the surface of venus, natural chemical reactions, aided and abetted by the properly engineered microbes, will expedite the precipitation of various solids or will combine the CO2 (the source of most of the pressure) with the surface rocks. I'm not enough of a chemist nor geo-chemist to be sure about the reasonablness of these assumptions. By intuition a planet that is less massive than the earth and exposed to more heat from the sun can be "encouraged" to modify or shed such a massive atmosphere no matter how many picks we have to dull trying.

I hope some of you already have a better scheme than I have proposed. Evaluation and criticism are most valuable prior to implementation. Let's do it from a "can do" perspective. ;)

Guest_Faulkner
2003-Dec-30, 02:01 PM
Maybe we should look at terraforming Earth first?

Just what does "terraform" mean? Breathable to humans? Or liveable? Either way, Earth is losing. There is scientific info out there (look it up yourselves) which says the oxygen in our atmosphere is running out.

Guest_Faulkner
2003-Dec-30, 02:42 PM
I read an article by Carl Sagan where he went into detail about how you can make it rain in hell (ie Venus). Goes into detail about how to terraform Venus. Check out his book - Cosmos for more details.


I just read "Cosmos"...oh hang on, no it was "Contact". I was gonna say, it was a real bad "2001" rip-off.

Didn't Carl Sagan work for the CIA?

jennyrussell
2003-Dec-30, 08:59 PM
I totally agree with thethorn that, before we start messing about with other planets, we should staighten things out here on our own first!

To answer the question: what is terraforming? It is the hypothetical process of altering the environment of a planet, specifically its atmosphere, to create an uncontained planetary biosphere that would make it suitable for human habitation (as opposed to an artificially contained system, such as a bio-dome). The word was first used by the science fiction writer, J. Williamson, in 1942.

There are four stages of terraforming a planet:

1) ecopoiesis (a term created by Prof. Robert Haynes to describe the creation of a "self-sustaining ecosystem, or biosphere, on a lifeless planet."

2) the introduction of anaerobic life

3) the introduction of aerobic life

4) terraforming


The principal problems with terraforming Venus are its proximity to the Sun, its massive atmosphere, its aridity, and its slow rotation. To make the planet habitable, planetary engineers wold have to remove almost all the gaseous carbon dioxide (vitually the entire atmosphere!) and process about 1% of into oxygen. Additionally, a substantial amount of water would have to be added. Even after the planet has cooled, steps would have to ba taken to prevent it from relapsing into a runaway greenhouse state, such as reducing the planet's insolation, whlst at the same time mantaining its high albedo. The lengths of the Venusian days and nights (each nearly two months long) would also have to be altered.

Thus far, the possibilities of even partially terraforming Venus lie well beyond the present capabilities of planetary engineers, although this doesn't stop them speculating on how it might be done. For those seriously interested in terraforming, there are two books which I would recommend - "Terraforming - Engineering Planetary Environments" by Martyn Fogg (1995 - USA: Society of Automotive Engineers) and "New Earths: Restructuring Earth and Other Planets" by James Oberg (1981 - USA: New American Library).

James Oberg was one of the first scientists to suggest importing large quantities of hydrogen from the atmosphere of Saturn to restore the chemical balance of the early Venusian atmosphere, and te reduce the amount of carbon dioxide, by producing carbon and water. Martyn Fogg's book is the most thoroughly comprehensive text on terraforming Venus and also Mars.

The possibilities of terraforming have long been an interest of mine, and I have just written a paper on the subject as part of an MSc. in Astronomy, which, I'm relieved to say, was very well received by the examiner. My conclusions were that we should continue research into terraforming, if only as a means of learning more about our own planet. It's no good messing Earth up, and then find ourselves forced to abandon the planet and move somewhere else to survive! Realistically, I think it's extremely unlikely that we will ever be able to fully terraform another planet, before our time runs out on this one. The planetary scientist, David Grinspoon, sums up my view when he says that homo sapiens may have intelligence, but it doesn't have wisdom or the capacity to act in the global interest!

Jenny

GOURDHEAD
2004-Jan-02, 03:38 AM
I sense that a few of you are somewhat timid about taking on the universe. We can not survive nor evolve unless we do. The universe will eliminate us if we don't; whether we are the only technologically sentient species in the whole universe or not.

We have problems here on earth but they are small and manageable by manipulating the environment and making adjustments to our life styles including genetically modifying as many species as we need to. Eternal vigilance and a good deal of tolerance for each other are necessary. The efficient management of energy and fresh water and use thereof will solve most of earth's problems. We must ensure that we develop alternative (with respect to fossil fuels) energy sources/supplies before we deplete the fossil fuels which are neeeded to develop and emplace the alternatives.

A total review and restructuring of copywright and patent laws is needed. The new rules should encourage the exchange of ideas and designs toward the benefit of humanity as a whole and should be less focussed on generating inordinate wealth for the holder. Newton claimed to have benefitted from standing on the shoulders of giants; surely any one of us has benefitted from many more than he, thus our ideas and designs are more of a cumulative nature across human intelligence than were those of earlier generators of ideas and designs. The admonition to "love our neighbor as ourself" should compel us to cooperate at a level required to freely exchange information needed to preserve the habitable state of the earth while also terraforming as much of the universe as we need. The trick is to avoid making mistakes that can not be corrected before the conditions generated by the mistake destroy us. The more planets/moons we have occupied; the less likely that a single mistake, or even a few, will terminate us. The nature of what we must do can not be done without making mistakes.

The universe, without evil intent, is violent, not predictable at levels we would like, and persistent. We must be vigilant, informed, focussed, risk takers, and risk managers. It may well be that the reason we don't detect any others is that they failed to see the universe for what it is and take appropriate precatuions.

alt_cosmos
2004-Jan-02, 04:59 AM
Hi,

Interested in Terraforming?

I've been working on the idea or a while now:

http://www.geocities.com/alt_cosmos/index.html

I'd enjoy any (constructive) criticism or feedback :]

Michael

GOURDHEAD
2004-Jan-02, 01:51 PM
Go Aussies!! Be cautious!! Be eternally vigilant!! :unsure:

The earth is but humanity's cocoon precariously attached to the solar system which is but a twig on the galactic tree. Now is the time for the imago to emerge and explore the tree----and eventually, its neighbors.

Shall our dreaming limit our vision of progress to having our descendants do less than engineer the expansion of the universe...with appropriate deference to the will and grace of God of course?

GOURDHEAD
2004-Jan-02, 03:09 PM
alt_cosmos:

Thanks for the link to your site. There's a lot of good information there for learning to dance with the devil of the details of terraforming. Reality, in the short run, can be frustrating, and, in the long run, a valued and trusted companion.

Although L and R0 will strongly influence the temperature of the atmosphere of the planet, why is the temperature not directly included in Equation 1? Also, does the frequency, at which the star's radiation peaks, play a significant role in terms of molecular disassociation?

alt_cosmos
2004-Jan-03, 07:41 AM
Hi,

Temperature is not directly used in Equation 1 as I wanted to show how minimal orbital velocity will influence the escape of Hydrogen from the atmosphere. I also wanted the equation to be usable for other star systems (variable L). When I did directly use temperature I had all the space-settler crazies arguing about temperature differentials and the greenhouse effect.

The frequency does play a role, however to include it you must take a multitude of other highly variable factors into account. I wanted to keep the equations easy, and use easily obtainable data, so I used averages for the solar "not-so-constant".

I'm currently working on an Equation that proves you can decrease a planet gravity and atmospheric pressure, by adding mass. I plan to use it to show how Venus can be terraformed without the need to land. This should remove the "Venu-cant-be-terraformed-because-of-its-air-pressure" arguement.

Michael
http://www.geocities.com/alt_cosmos/index.html

damienpaul
2004-Jan-03, 07:47 AM
what would the effect of firing comets into the atmosphere of venus be? would it be of assistance?

SHSUBearkat
2009-Mar-11, 02:12 AM
I know that venus has a nasty greenhouse effect, so we would need to make Venus' atmosphere more human friendly. Even then, I would suppose that the temperatures would be very high, so I'm not sure Venus would be a great idea.

WayneFrancis
2009-Mar-11, 05:00 AM
What is with all these old post getting dug up?
SHSUBearkat have you ever thought that after 5 years the people asking the question might not be monitoring this thread anymore?

Neverfly
2009-Mar-11, 05:08 AM
What is with all these old post getting dug up?
SHSUBearkat have you ever thought that after 5 years the people asking the question might not be monitoring this thread anymore?

Notice SHSUBearkat's post count.

It takes a bit of getting used to to check "Last Post Date" and it's VERY easy to not notice it.

I've done some thread necromancy myself without realizing it.
And I actually appreciate some of the old threads being pulled to the surface as some are quite interesting.


There is currently a discussion about this in Forum Feedback.

GOURDHEAD
2009-Mar-11, 02:25 PM
what would the effect of firing comets into the atmosphere of venus be? would it be of assistance?If Ganymede and Callisto are mostly ice, together they might make a noticeable difference, but not a very significant one. There's a lot of thermal capacity tied up in the configuration of Venus. Short of the hypothesized Oort cloud population, there may not be enough thermal capacity in all the comets to counter that of Venus.

neilzero
2009-May-26, 05:13 PM
I have likely posted details on terraforming Venus more recently than 2004. Terraforming requires several heroic technologies. Statite sun shades could block most of the Solar energy reaching Venus. Venus would cool significantly in a few years, not a million years, unless we are trying for minus 100 f to to make dry ice out of the carbon dioxide. Without sunlight we can not use photosynthesis to convert the carbon dioxide to bio-char and oxygen. Some of the free oxygen would react with the rocks on the surface, but we could have too much free oxygen in the atmosphere by converting as little as 1% of the carbon dioxide.
Venus does not have enough hydrogen to make more than one small shallow ocean, so the water for photosynthesis is a problem. Daily comet impacts interfere with almost everything else we might want to do, unless they are small comets that vaporize completely before reaching the surface, or we can restrict the comet impacts to less than half of Venus = extreme accuracy requirement. Worse sulphuric acid bonds strongly to water, so we would get weak acid instead of free water.
My guess is we should start with perhaps 5% of the area of Venus near the North pole of Venus. It already has one of the tallest mountain ranges on Venus. We surround that area with a snow fence = more correctly a dust fence, more heat tolerant than the plastic dust fences required by EPA for many construction sites. For best results, more than one thousand miles of double fence.
Now we can begin adding algae, water and fertilizer to the narrow band of upper atmosphere, where the temperature is suitable. This is a huge project as much of the stuff we deliver will fall to altitudes which are too hot to grow algae. The sulphuric acid is mostly in a narrow band closer to the surface, so this is not a near term problem. The high altitude winds spiral around the Northern Hemisphere ending in a great polar down draft. As the algae descends it becomes bio-char = algae charcoal. Surface winds near the North pole are toward the equator. The dust fence will deposit the algae charcoal, and other dust just outside the fence. We will need to move the fence as it becomes buried. Over several thousand years the fence location will become a mountain range which will block the rare North bound surface winds allowing the polar plateau to cool. Shortly before the sulphuric acid rain reaches the surface, we will cover the Arctic plateau (perhaps a million square miles) with an impervious coating, so the acid will not sink into the very dry bio-char and dust, This will be very acid mud as the dust continues to arrive with the strong acid. After a few years we will move the statite sunshades so they provide less shade; the rain will stop until we install another impervious layer. We will repeat this several (many?) times until nearly all the sulphuric acid is sequestered inside the growing polar plateau. Now fresh water rain will fall. so we can think agriculture on the higher portions of the polar plateau. The atmosphere is still almost 90% carbon dioxide, about 0.3% free oxygen which is optimum for humans at about 80 atmospheres. We will have to genetic engineer the humans, and they will need a prosthesis to remove carbon dioxide from their blood. The algae program can now be reduced, as more than 0.3% oxygen at 80 atmospheres will be a major fire hazard. We sort of terraformed about 5% of Venus.
Advantages are: it took less than one million years. Up to a billion genetically altered humans can live on the surface of Venus. There is a million year supply of sulphuric acid which can be pumped to the surface as needed. New technology and new ideas can terraform more of Venus if that is a good option. The mile plus layer of algae charcoal is good insulation so the internal heat of Venus cannot reach the new surface. The old surface under the center of the Arctic plateau may be as hot as 1000 degrees c. Will the plateau sink due to it's weight? Neil

Fiery Phoenix
2009-May-26, 05:19 PM
I really don't see why one would want to terraform a hellish place like Venus when Mars is obviously the more appropriate choice. That being said, let's colonize our own Moon first before we can attempt to terraform and colonize the planets.

neilzero
2009-May-27, 01:44 AM
Polar colonies up to a few hundred humans on Mercury may work well, because the sun never shines at the bottom of polar craters. It is almost as hot as Venus at the edge of the creator but the bottom stays cold -133c according to one measurement. Mirrors a few inches above the rim can supply small amounts of light and heat to optimise the colony temperature. This is possible because Mercury and our moon have almost no air. We think Mercury and our moon will loose any atmosphere we bring there in a few thousand years, perhaps even faster. Mars with more gravity and weaker solar wind can likely retain an atmosphere for a few million years, even if we cannot give Mars a magnetic field.
Colonies can be built many miles below the surface of planets, moons, asteroids and comets that do not come much closer to the sun than Earth, except for the 4 gas giant planets, which likely do not have a surface anything like Earth.
A major disadvantage of deep underground colonies is a gently sloping tunnel to the surface is perhaps 100 miles long. Elevators are possible but high maintenance items. Catastrophic failure is the main hazard of human built colonies in solar orbit or other orbit. Neil

omegaclass
2009-Aug-16, 03:03 AM
i was looking into Venus and found a guy that has a totally different theory on making Venus habitable any opinions?

terraforming-venus-and-the-myth-of-runaway-greenhouse
(http://graemebird.wordpress.com/2008/07/11/terraforming-venus-and-the-myth-of-runaway-greenhouse/)

he dose make some interesting points that should be looked into.

DaveDennis
2010-Jan-12, 09:16 AM
After watching Earths Evil Twin on National Geographic I had an idea that could solve 2 major problems of terraforming Venus.

Solar wind

Long day.

My idea is to use the energy of the super rotating atmosphere to speed up the planet’s rotation. This will shorten the day of course but also kick start the magnetic field and deflect the solar wind in the same way as earth’s magnetic field does.

Ok this is far fetched. Lower an anchor from a kite flying in the super rotating wind to the ground. It’s bound to catch on something. It doesn’t need to be a fixed point on the ground and slippage just like a sea anchor is not a disaster. Then repeat millions of times.

eburacum45
2010-Jan-12, 11:18 AM
The kites could be used to generate power (electricity)- enough to run a substantial civilisation - but not enough, I'm afraid, to alter Venus' rotation very much. Venus is very massive compared to its atmosphere; the amount of energy in the atmosphere is tiny compared to the energy required to substantially alter its day length.

traceur
2010-Jan-12, 01:27 PM
i'm really not that certain i understand why you'd need to shorten the day night cycle: it seems long enough for an entire generation of flora to live entirely within the sunlight region, sure they'll die out at the edges but wouldn't the winds spread the oxygen all around the planet? as for food supply i somehow doubt that any civilization advanced enough to terraform the Venusian atmosphere isn't advanced enough to have the same globalization we have - and many regions today on earth aren't exactly self-sufficient in agriculture.
plus after a few cycles there would be enough nutrition in the soil from dead plants for mushrooms and fungai to grow at the night side, and vitamin D decencies are already treatable today.

DaveDennis
2010-Jan-12, 11:09 PM
The kites could be used to generate power (electricity)- enough to run a substantial civilisation - but not enough, I'm afraid, to alter Venus' rotation very much. Venus is very massive compared to its atmosphere; the amount of energy in the atmosphere is tiny compared to the energy required to substantially alter its day length.

I agree that the atmosphere doesn't have enough momentum to alter the spin of the planet significantly. But that is like saying the crank shaft and pistons in your car's engine don't have enough momentum to move your car. The point is that the super rotation is an engine powered by the sun. Its not going stop anytime soon. Super rotation continues to astound me. The moving parts of the atmosphere circle the planet in 4 hours. The speed is 60 times faster than the planet's rotation.

DaveDennis
2010-Jan-12, 11:11 PM
i'm really not that certain i understand why you'd need to shorten the day night cycle: it seems long enough for an entire generation of flora to live entirely within the sunlight region, sure they'll die out at the edges but wouldn't the winds spread the oxygen all around the planet? as for food supply i somehow doubt that any civilization advanced enough to terraform the Venusian atmosphere isn't advanced enough to have the same globalization we have - and many regions today on earth aren't exactly self-sufficient in agriculture.
plus after a few cycles there would be enough nutrition in the soil from dead plants for mushrooms and fungai to grow at the night side, and vitamin D decencies are already treatable today.

Yes it is important to shorten the day. Without a magnetic field solar wind will create havoc in a newly terraformed atmosphere. Energised particles will break down water and the hydrogen will be lost to space. Earths magnetic field occurs because of relative motion between its solid iron inner core and its liquid iron outer core. Its a self exciting dynamo. It needs to spin.
Its safe to assume that Venus has similar solid inner and liquid outer iron cores. What is missing is the rotation.

IsaacKuo
2010-Jan-12, 11:39 PM
I agree that the atmosphere doesn't have enough momentum to alter the spin of the planet significantly. But that is like saying the crank shaft and pistons in your car's engine don't have enough momentum to move your car. The point is that the super rotation is an engine powered by the sun. Its not going stop anytime soon.
It sure won't stop, nor will it have a significant effect on Venus's rotation.

The bottom line is that the sun does NOT impart a torque onto the wind. It neither adds to nor removes from Venus's overall angular momentum. You may think your kites are a cool idea, but the drag from your kites is peanuts compared to the natural drag that has already existed between the wind and the land. If super-rotating winds haven't sped up Venus's rotation in billions of years, what chance do your kites have?

DaveDennis
2010-Jan-14, 07:05 AM
The torque from sunlight thing is not as clear cut as you would have us believe.
Thinking about angular momentum.
On average the angular momentum of the atmosphere with respect to the planet canít be zero.
That would imply the existence of counter rotating winds. There is no evidence of them.
Super-rotation is defined as:
ďA phenomenon in which the atmosphere of a planet rotates independently of the surface.Ē

Letís consider the angular momentum of the planet plus atmosphere as a whole. Say angular momentum of this system is conserved, that is it neither increases or decreases by the addition of sunlight. That must follow in order for the atmosphere to gain momentum the planet must lose some. In other words the planetís rotation must slow down in order for the atmosphere to speed up.
That doesnít make sense. What process could possibly be responsible for slowing the planet so the atmosphere can speed up?

We know that the atmosphere is rotating. It follows that it has had a torque applied to it.

Torque from sunlight is real.
There are 2 effects that Iím aware of:-
1. Thermal transpiration . Occurs in a radiometer. http://en.wikipedia.org/wiki/Crookes_radiometer
2. The ďYORPĒ effect. Sunlight on its own has been shown to spin asteroids http://physicsworld.com/cws/article/news/27276
So why hasnít super-rotation had any effect on the planetís after a few billion years?
Super-rotation occurs at altitude (around 70km) not ground level. So interaction with the surface is minimal. .

Back to my kites.
Anything dragging on the rotating atmosphere from the planet will exert torque on the planet.
I came up with the kite idea because I was thinking about a passive device to couple the momentum of super-rotation to the planet. Kites will do this.
Terraforming is planetary scale and technologies that don't exist. We are free to use our imaginations. I imagine big kites with strong strings. Itís a scalable solution.
Is it any more ridiculous to lower a mass driver to the surface and firing dry ice into space?
Ease up on the new guy.

IsaacKuo
2010-Jan-14, 02:49 PM
The torque from sunlight thing is not as clear cut as you would have us believe.
In this case, it is.

That would imply the existence of counter rotating winds.
No, it implies that there is some cause for the extra rotation, that is all.

Super-rotation is thought to be caused by a combination of topographical torque (torque against terrain) and Hadley circulation. The way Hadley cells get their rotation is because of convective circulation causing airflows toward and away from the poles/equator. As air flows toward the axis, the flow is deflected spinward; as air flows away from the axis, the flow is deflected anti-spinward. This is because of conservation of angular momentum and the change in radius; the same effect as when an ice skater pulls her arms in/out. However, things are complicated by terrain and weather effects so actual wind patterns are not so simplistic.

Torque from sunlight is real.
There are 2 effects that Iím aware of:-
1. Thermal transpiration . Occurs in a radiometer. http://en.wikipedia.org/wiki/Crookes_radiometer
2. The ďYORPĒ effect. Sunlight on its own has been shown to spin asteroids http://physicsworld.com/cws/article/news/27276
Neither of these effects are relevant to Venus, since Venus is symmetric (forced that way by gravity).

So why hasnít super-rotation had any effect on the planetís after a few billion years?
Super-rotation occurs at altitude (around 70km) not ground level. So interaction with the surface is minimal. .
Sorry, but there's no such thing as a frictionless bearing. Whether you like to believe it or not, there's immense friction between the atmosphere and the surface. Thus any difference between the rotation of the surface and the rotation of the atmosphere must be due to an actively powered phenomena. Superrotation is not a well understood phenomena yet, but there are a great many things which clearly do not cause it.

I imagine big kites with strong strings. Itís a scalable solution.
Is it any more ridiculous to lower a mass driver to the surface and firing dry ice into space?
Well, it is worthy of more ridicule because it can't work, rather than merely probably won't work.

Ease up on the new guy.
I'm not attacking you, I'm attacking your idea. Unfortunately, your idea can't work.

captain swoop
2010-Jan-14, 05:29 PM
DaveDennis. Welcome to BAUT. Please take some time to read the rules for posting linked at the bottom of this post.
This Forum (Q&A) is for asking and answering questions on the Mainstream of Astronomy. If you want to start a speculative discussion about kites speeding up planets this is not the place for it.

jogleby
2010-Jan-14, 06:17 PM
One of the main problems with terraforming Venus is its thick, carbon dioxide rich atmosphere. I think we could take care of that problem easily. One word: Megamaid. Just make sure she is set to "Suck."