terraforming venus

[alt_cosmos]

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]

what would the effect of firing comets into the atmosphere of venus be? would it be of assistance?

[SHSUBearkat]

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]

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]

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]

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]

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]

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]

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]

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


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

[DaveDennis]

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]

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]

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]

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]

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]

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]

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 can’t be zero.
That would imply the existence of counter rotating winds. There is no evidence of them.
Super-rotation is defined as:
“A phenomenon in which the atmosphere of a planet rotates independently of the surface.”

Let’s 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 planet’s rotation must slow down in order for the atmosphere to speed up.
That doesn’t 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 I’m aware of:-
1. Thermal transpiration . Occurs in a radiometer. http://en.wikipedia.org/wiki/Crookes_radiometer
2. The “YORP” effect. Sunlight on its own has been shown to spin asteroids http://physicsworld.com/cws/article/news/27276
So why hasn’t super-rotation had any effect on the planet’s 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. It’s 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]

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 I’m aware of:-
1. Thermal transpiration . Occurs in a radiometer. http://en.wikipedia.org/wiki/Crookes_radiometer
2. The “YORP” 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 hasn’t super-rotation had any effect on the planet’s 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. It’s 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]

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]

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."