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GOURDHEAD
2004-Dec-02, 02:49 PM
The data I've seen on the atmosphere of Venus indicates that its atmosphere contains 3% nitrogen and, although sulfuric acid clouds abound, no quantitative value for the mass of the sulfuric acid is stated. With conversion of Venus' atmosphere to one more suitable to humans in mind, do any of you know how to compute the mass of solids and liquids that would result from its current surface pressure of 90 bars down to 3 or less bars? If we could do this and leave the nitrogen as is, would we have too much (3% of 90 bars is 2.7 bars or is the calculation more complex?). How can we calculate the amount of H2O available from separating the H2SO4 into H2O + SO2 +O. I seem to remember seeing data that indicate the sulfuric acid clouds are from 10 to 20 kilometers thick with pressures varying from about 0.5 bars to 2 bars. Is this corect?

I'm not sure I understand scale factor as it applies to atmospheres but it seems that on Venus for every 15,000 kilometers increase in altitude, the atmospheric pressure is reduced by 1/2.718 bars. If 2.718 is raised to the 4.5th power, the result is between 89 and 90. Does that mean that the atmospheric pressure on Venus at an altitude of 67.5 (15 times 4.5) kilometers is near one bar?

Assuming we can produce the magic microbes to do all the work including integrating the leftover sulfur and carbon into the venusian crust with the help of the "ocean" of water from the breakdown of the sulfuric acid, how much water and crust material would we get?

Another oddity about the Venusian atmosphere is that the temperature is said to be stable and the same on the lighted and dark sides; yet I seem to remember reading of wind speeds exceeding 100 kilometers/hour in the upper atmosphere. If there is no temperature differential, how are pressure differentials generated to power the wind speeds?

Any helpful links or printed references would be appreciated.

GOURDHEAD
2004-Dec-31, 03:13 PM
Where are all the comments, criticisms, etc.,?

ChromeStar
2005-Jan-01, 03:45 PM
Hey GROUNDHEAD :D

I don't know how to answer your questions, but i would be very intrested in the data you've seen.

perhaps you could help me out?

GOURDHEAD
2005-Jan-02, 02:57 AM
Here (http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html), here (http://zebu.uoregon.edu/~soper/Venus/atmosphere.html), and here (http://spacelink.nasa.gov/NASA.Projects/Space.Science/Solar.System/Pioneer.Venus/Venus.Discoveries) are some links to Venus' atmosphere data.

ChromeStar
2005-Jan-02, 11:34 AM
Thanx a lot :D

GOURDHEAD
2005-Jan-02, 01:51 PM
This (http://www.ebicom.net/~rsf1/vel/1918vpt.htm) directly equates temperature and pressure values of Venus' atmosphere.

GOURDHEAD
2005-Jan-02, 07:54 PM
It can be seen from the temperature and pressure profiles that the pressure region from about 0.8 bar to 3 bars nicely overlaps the region of comfortable temperatures for most Earth biota. Recent observed increases in the amount of molecular oxygen may be due to inadvertant deposits of Earth bacteria by previous visits from Earth vehicles....or, more likely, anomalous measurements. The one bar region looks promising as a port of entry for terraformation.

Svemir
2005-Jan-04, 06:34 AM
I think "magic microbs" are right around the corner.

eburacum45
2005-Jan-04, 08:16 AM
Although a biological solution might be found to terraforming Venus, it would probably take hundreds of thousands of years to take effect; microbes are slow workers when it comes to atmosphere change, and the heat problem would remain. I think active cooling systems will be required;
try shading the planet with a giant sunshade in the Lagrange 1 position;
and perhaps extracting CO2 using massive iron pellets which could also carry away heat. These pellets would be dipped into the atmosphere usung magnetic loop technology, and once out of the atmosphere would radiate heat away.

hot iron pellets would absorb CO2 quite well.
These iron pellets could be sent from Mercury by mass driver.

GOURDHEAD
2005-Jan-04, 01:09 PM
Although a biological solution might be found to terraforming Venus, it would probably take hundreds of thousands of years to take effect; microbes are slow workers when it comes to atmosphere change, and the heat problem would remain. I think active cooling systems will be required; try shading the planet with a giant sunshade in the Lagrange 1 position
With a little help from our genetic engineers the microbes can be "farmed" to pull it off in a few hundred years. Some can double in mass in about 20 minutes when propely cared for. I like the LaGrange point 1 position shade. We need the practice.

Maybe we can induce the microbes to construct a living shade suspended at about 70 or 80 kilometers altitude in the form of a living mat.

Still missing (unknown to me) are data on the tonnage of H2SO4 available as a water source. It'd be a shame to have to sacrifice Callisto to get the water. Looks like Mars could use some of that extra Venusian CO2 and N2 not to mention large heat reflectors at its LaGange points 4 and 5. Ah-h-h-h-h I love it when a plan comes together!

filrabat
2005-Jan-19, 07:53 AM
Re: sunshade at L1

How "in this solar system" are we ever going to even find enough material to build such a thing, let alone actually build it?? That parisol would have to be at least thousands of km in diameter, especially for a hothouse like Venus. Don't forget about the thickness of it, so as to make it structurally stable (do i even have to ask about effects of the light pressure and solar ejectae pressure on the parisol?).

GOURDHEAD
2005-Jan-19, 01:29 PM
How "in this solar system" are we ever going to even find enough material to build such a thing, let alone actually build it?? That parisol would have to be at least thousands of km in diameter, especially for a hothouse like Venus. Don't forget about the thickness of it, so as to make it structurally stable (do i even have to ask about effects of the light pressure and solar ejectae pressure on the parisol?). You are wise to point out the more difficult aspects of the challenge. Now let's hope you and others will begin to brainstorm solutions or even provide a better approach.

The parasol does not need to be permanent nor to completely shade Venus from the sun; we could pursue it to the extent it is practical. Thicknesses of a few inches should suffice. Bringing the temperature of Venus down is a challenge from which we must not shrink. The parasol could, and should, be built in sections of manageable sizes...think venetian blinds. Maybe instead of anchoring the parasol to LaGrange Point 1 we allow the sections to orbit Venus and manage the effects of radiation presssure to minimize the adverse consequences. By shooting for a Venusian ice age we may achieve earthlike tropical zones near the poles of Venus.

My preferred choice is a carefully chosen set of carefully engineered microbes. Think how convenient it would be for large colonies of them to form living mats high in the venusian atmosphere with reflective surfaces which they always present to solar radiation. Is there already a company named General Biophysics or do we need to form one?

filrabat
2005-Mar-11, 06:52 AM
Gourd, I have to admit you made me think about this one. So here’s my best solution, for what it’s worth.

I originally wanted to use a space elevator to pump some of the excess CO2 out of the atmosphere, but then realized that the orbital end of the space elevator needed to be in “local geosynchronous” orbit in order to work. Since Venus’s rotational period is a WAY hefty portion of its year, this would mean the orbiting end of the elevator needs to be absurdly far from the planet in order for this to work. In fact, we’d probably do better with a simple parasol! (For comparison, geosynchronous orbit for a planet with Earth’s mass – very comparable to Venus’s – is 42,300 km, or 26,289.62 miles. But that is only for such a mass with exactly the same rotation period as the earth).

I suppose we could direct several 100 km (60 miles) –wide asteroids toward Venus to blast away much of it’s atmosphere. Undoubtedly it would take less energy and effort than building a parasol. Yet, we are still confronted with the problem of the large amount of solar energy at this distance, and thus we will still need to use the parasol regardless. The only other solution I can conjure up is to use a Venetian blinds parasol, as Gorud says. However, I’d also want to add some steering rockets on the parasol’s edges so that when the tilt of those blinds inevitably gets out of kilter, they can be steered back into place. We could probably use some solar-based power source for the rocket fuel.

Likely, we would have to use a combination of these methods to get Venus to a reasonably habitable temperature for human beings.

GOURDHEAD
2005-Mar-11, 12:50 PM
Assuming Venus is 0.6AU from the sun and that Earth intercepts 1300 watts of total radiation per square meter, Venus intercepts 1300/0.36 or about 3611 watts/M^2, almost 3 times that of Earth. This heat load should be manageable once we rid Venus of its residual heat. As can be seen from my previous inputs, I am a believer in microbes and our ability to engineer them to do our bidding thus keeping other aspects of terraforming to a minimim. Also, industrial chemists and molecular physicists may be able to design endothermic molecules that will allow us to store heat as potential energy in material to be used for surface transportation and other "housekeeping" tasks on the planet's surface. The development of such technology will have application back on Earth as a regulator of global warming.

I haven't done the arithmetic, but my guess is that a space elevator for Venus is highly improbable. Remember its center of mass must be at a distance commensurate with synchronicity. I believe that will place it, on different occasions, too near Earth, Mercury, and the sun for it to remain stable for even one Venusian orbit about the sun. Also, after we cool Venus down the temperature differential between its dark and sunlit sides will cause severe upper altitude winds.

eburacum45
2005-Mar-11, 07:14 PM
You make the parasol of very light carbonfibre weave, buckyfibre if feasible;
the parasol is spun to retain it's shape, and has a system of guy ropes attached to a counterweight situated some way towards the Sun. This balances light pressure and the solar wind; if there is an increase in solar wind speeds the counterweight is run out on a tether towards the Sun, increasing the drag on the parasol.

In extreme winds the parasol starts to behave more like a parachute;
actively controlled flaps and openings should allow the parasol to keep station even even if hit by a Coronal Mass Ejection.

bossman20081
2005-Mar-11, 08:21 PM
Originally posted by filrabat@Mar 11 2005, 03:22 AM
I suppose we could direct several 100 km (60 miles) –wide asteroids toward Venus to blast away much of it’s atmosphere. Undoubtedly it would take less energy and effort than building a parasol. Yet, we are still confronted with the problem of the large amount of solar energy at this distance, and thus we will still need to use the parasol regardless. The only other solution I can conjure up is to use a Venetian blinds parasol, as Gorud says. However, I’d also want to add some steering rockets on the parasol’s edges so that when the tilt of those blinds inevitably gets out of kilter, they can be steered back into place. We could probably use some solar-based power source for the rocket fuel.

Likely, we would have to use a combination of these methods to get Venus to a reasonably habitable temperature for human beings.
I'm curious, couldn't we blast some smaller asteroids into dust around Venus? The dust could block out some sunlight, thus lowering it's temperature. If this would work, it would definently be easier then building a huge parasol.

eburacum45
2005-Mar-11, 11:44 PM
Possibly; that would be a relatively low tech way of acheiving the cooling.

Mind you, there are some problems with it; the dust would form a ring, which would gradually collapse into a flat plane aligned with Venus' equator.- which would not afford as much shade as a torus. Also most of the ring would not actually shade the planet at all- which means you have to make the dust cloud much more massive than the parasol.
The requirement therefore is for a few fairly massive objects to be dismantled in to Venus orbit- this would take a heck of a lot of energy- much more than building a thin parasol.

However you could just possibly achieve all this by arranging a collision between two asteroids right next to Venus; you could even get these objects from the Outer Solar system where gravity is weak (there are plenty of Centaurs out near Neptune).

But you would need to aim these objects very, very accurately.