The Atmosphere of Venus as a place to live

Tom Kalbfus · 2016-05-15 14:10:08

This may be useful in plotting where to put humans in the Venusian environment:

This chart shows the optimum altitude for a human space settlement in the atmosphere of Venus to be around 36.25 miles in altitude. The vortexes at the poles are also interesting, if you don't want your settlement to drift around the planet all the time.
Circulation

https://en.wikipedia.org/wiki/Atmosphere_of_Venus

The circulation in Venus's troposphere follows the so-called cyclostrophic approximation.[4] Its windspeeds are roughly determined by the balance of the pressure gradient and centrifugal forces in almost purely zonal flow. In contrast, the circulation in the Earth's atmosphere is governed by the geostrophic balance.[4] Venus's windspeeds can be directly measured only in the upper troposphere (tropopause), between 60–70 km, altitude, which corresponds to the upper cloud deck.[23] The cloud motion is usually observed in the ultraviolet part of the spectrum, where the contrast between clouds is the highest.[23] The linear wind speeds at this level are about 100 ± 10 m/s at lower than 50° latitude. They are retrograde in the sense that they blow in the direction of the retrograde rotation of the planet.[23] The winds quickly decrease towards the higher latitudes, eventually reaching zero at the poles. Such strong cloud-top winds cause a phenomenon known as the super-rotation of the atmosphere.[4] In other words, these high-speed winds circle the whole planet faster than the planet itself rotates.[22] The super-rotation on Venus is differential, which means that the equatorial troposphere super-rotates more slowly than the troposphere at the midlatitudes.[23] The winds also have a strong vertical gradient. They decline deep in the troposphere with the rate of 3 m/s per km.[4] The winds near the surface of Venus are much slower than that on Earth. They actually move at only a few kilometres per hour (generally less than 2 m/s and with an average of 0.3 to 1.0 m/s), but due to the high density of the atmosphere at the surface, this is still enough to transport dust and small stones across the surface, much like a slow-moving current of water.[1][24]

Meridional (north–south) component of the atmospheric circulation in the atmosphere of Venus. Note that the meridional circulation is much lower than the zonal circulation, which transports heat between the day and night sides of the planet
All winds on Venus are ultimately driven by convection.[4] Hot air rises in the equatorial zone, where solar heating is concentrated, and flows to the poles. Such an almost-planetwide overturning of the troposphere is called Hadley circulation.[4] However, the meridional air motions are much slower than zonal winds. The poleward limit of the planet wide Hadley cell on Venus is near ±60° latitudes.[4] Here air starts to descend and returns to the equator below the clouds. This interpretation is supported by the distribution of the carbon monoxide, which is also concentrated in the vicinity of ±60° latitudes.[4] Poleward of the Hadley cell a different pattern of circulation is observed. In the latitude range 60°–70° cold polar collars exist.[4][7] They are characterised by temperatures about 30–40 K lower than in the upper troposphere at nearby latitudes.[7] The lower temperature is probably caused by the upwelling of the air in them and by the resulting adiabatic cooling.[7] Such an interpretation is supported by the denser and higher clouds in the collars. The clouds lie at 70–72 km altitude in the collars—about 5 km higher than at the poles and low latitudes.[4] A connection may exist between the cold collars and high speed midlatitude jets in which winds blow as fast as 140 m/s. Such jets are a natural consequence of the Hadley–type circulation and should exist on Venus between 55–60° latitude.[23]

Odd structures known as polar vortices lie within the cold polar collars.[4] They are giant hurricane-like storms four times larger than their terrestrial analogs. Each vortex has two "eyes"—the centres of rotation, which are connected by distinct S-shaped cloud structures. Such double eyed structures are also called polar dipoles.[7] Vortexes rotate with the period of about 3 days in the direction of general super-rotation of the atmosphere.[7] The linear wind speeds are 35–50 m/s near their outer edges and zero at the poles.[7] The temperature at the cloud-tops in the polar vortexes are much higher than in the nearby polar collars reaching 250 K (−23 °C).[7] The conventional interpretation of the polar vortexes is that they are anticyclones with downwelling in the centre and upwelling in the cold polar collars.[4] This type of circulation resembles the winter polar anticyclonic vortexes on Earth, especially the one found over Antarctica. The observations in the various infrared atmospheric windows indicate that the anticyclonic circulation observed near the poles may penetrate as deep as to 50 km altitude, i.e. to the base of the clouds.[7] The polar upper troposphere and mesosphere are extremely dynamic; large bright clouds may appear and disappear over the space of a few hours. One such event was observed by Venus Express between 9 and 13 January 2007, when the south polar region became brighter by 30%.[23] This event was probably caused by an injection of sulfur dioxide into the mesosphere, which then condensed forming a bright haze.[23] The two eyes in the vortexes have yet to be explained.[25]

False colour near infrared (2.3 μm) image of the deep atmosphere of Venus obtained by Galileo. The dark spots are clouds silhouetted against the very hot lower atmosphere emitting thermal infrared radiation.
The first vortex on Venus was discovered at the north pole by the Pioneer Venus mission in 1978.[26] A discovery of the second large 'double-eyed' vortex at the south pole of Venus was made in the summer of 2006 by Venus Express, which came with no surprise.[25]

Antius · 2016-05-15 16:38:59

The atmosphere of Venus would be a lousy place to live for a multitude of reasons. The tolerable temperature zones are right in the middle of the sulphuric acid cloud zone. Building habitats that can stand up to that for extended periods is an engineering challenge. And the habs must rely on bouyant lift, which imposes severe weight restrictions. You cannot easily access the surface for building materials, so you are pretty much stuck with whatever you can mine out of the atmosphere, which isn't much. You are at the bottom of a deep gravity well, so importing and exporting is expensive. All in all it is difficult to imagine an economic case for moving into such a difficult environment.

Venus orbit might be a better place to live. You can mine the atmosphere from orbit, using high ISP electric propulsion to counter the drag. The same propulsion allows you to import stuff that you need and export stuff to pay for it. You always have to have that balance. The planet does have a thick atmosphere that might be useful for capturing asteroids in a location relatively close to Earth. As for the planet itself, aside from carbon, nitrogen and oxygen, Venus doesn't really offer anything useful until we can access its surface. And that requires terraforming.

Last edited by Antius (2016-05-15 16:43:00)

Tom Kalbfus · 2016-05-15 20:26:13

Antius wrote:

The atmosphere of Venus would be a lousy place to live for a multitude of reasons. The tolerable temperature zones are right in the middle of the sulphuric acid cloud zone. Building habitats that can stand up to that for extended periods is an engineering challenge. And the habs must rely on bouyant lift, which imposes severe weight restrictions. You cannot easily access the surface for building materials,

I made a chart, interpolated from the Wikkipedia entry, turns out the optimum altitude is 36.25 miles, where the average temperature is 70 degrees F. Naturally this is within the Sulfuric Acid clouds, because this is where the water clouds would be. I believe at this level, the clouds would be patchy, that is the habitat wouldn't be in one continuous layer of sulfuric acid clouds, but there will be some clear areas with blue sky and some cloudy areas as well, depending on the particular weather, below will be a continuous layer of unbroken clouds, if you want to avoid this, you'd have to go to a higher altitude, where sulfuric acid freezes, I suspect sulfuric acid ice crystals would be less corrosive. As for accessing the ground 36.25 miles is only six times the height of Mount Everest, it should be possible to send an airship down to get some material. Larger vehicles last longer in the intense heat, because they have more internal volume per surface area, so it takes them longer to equalize their internal temperature to the surrounding atmosphere. So long as a vehicle is well insulated, if can do some useful work on the surface before having to ascend to cool off, and they need not have to ascend all the way to 36 miles, they just need to ascend high enough so that refrigeration can work and they can shed heat through radiator fins mechanically to build up a store of cold inside. The Venusian lower atmosphere is pretty dense, a vehicle designed to move through it would be built much like a submarine, and it can be powered by steam, simply by bringing a supply of water down with it, and then exposing the boiler to the atmosphere and the water inside will boil, and this can propel the submarine through the thick atmosphere until the water runs out! It can scoop some dirt then blow its ballast tanks and ascend like a submarine until it needs a balloon to go higher.

so you are pretty much stuck with whatever you can mine out of the atmosphere, which isn't much. You are at the bottom of a deep gravity well, so importing and exporting is expensive. All in all it is difficult to imagine an economic case for moving into such a difficult environment.
Venus orbit might be a better place to live. You can mine the atmosphere from orbit, using high ISP electric propulsion to counter the drag. The same propulsion allows you to import stuff that you need and export stuff to pay for it. You always have to have that balance. The planet does have a thick atmosphere that might be useful for capturing asteroids in a location relatively close to Earth. As for the planet itself, aside from carbon, nitrogen and oxygen, Venus doesn't really offer anything useful until we can access its surface. And that requires terraforming.

Antius · 2016-05-16 13:39:17

According to this website, the only material that provides good long term resistance to concentrated sulphuric acid is teflon. http://www.inyoprocess.com/chemicals-ma … html?id=11

The website also notes that concentrated sulphuric has the viscosity of honey. This would suggest to me that it would play havoc with the bouyancy of any 'cloud city'. The best metallics are stainless steels and nickel based alloys. In anaerobic conditions, corrosion rates can be as little as 0.1mm per year.

So a cloud city could concievably last years. It would be a lot more workable above the cloud layer, it might even be easier to place the city beneath it. The bouyant lift would be greater, materials issues reduced - stainless steels would work beneath the acid layer. And the extra lift would allow the city to carry a heat pump to remove excess heat. Beneath the cloud layer, a nuclear reactor would be needed to generate power. With atmospheric density at several kg per cubic metre, it could be virtually unshielded if it were hung from a long tether.

Last edited by Antius (2016-05-16 13:50:33)

Tom Kalbfus · 2016-05-17 05:09:53

Antius wrote:

The atmosphere of Venus would be a lousy place to live for a multitude of reasons. The tolerable temperature zones are right in the middle of the sulphuric acid cloud zone. Building habitats that can stand up to that for extended periods is an engineering challenge. And the habs must rely on bouyant lift, which imposes severe weight restrictions. You cannot easily access the surface for building materials, so you are pretty much stuck with whatever you can mine out of the atmosphere, which isn't much. You are at the bottom of a deep gravity well, so importing and exporting is expensive. All in all it is difficult to imagine an economic case for moving into such a difficult environment.
Venus orbit might be a better place to live. You can mine the atmosphere from orbit, using high ISP electric propulsion to counter the drag. The same propulsion allows you to import stuff that you need and export stuff to pay for it. You always have to have that balance. The planet does have a thick atmosphere that might be useful for capturing asteroids in a location relatively close to Earth. As for the planet itself, aside from carbon, nitrogen and oxygen, Venus doesn't really offer anything useful until we can access its surface. And that requires terraforming.

We could do this. This is the Venus suspension bridge, it uses space elevator technology. The outer ring is above the 24-hour orbit, we suspend cables down to just above the atmosphere and construct a suspension bridge. We can start small with just one space elevator and a city hanging from it, from this position, it can gather nitrogen from the atmosphere, the relative velocity is that of a jetliner.

GW Johnson · 2016-05-17 16:38:52

Tom:

I do NOT understand this seeming obsession you have with sending humans to live at Venus. The place is a pretty good approximation to the Biblical descriptions of Hell.

No one in their right mind would ever volunteer to go there and live, not until we can terraform the place into something more Earth-like. That outcome doesn't matter whether you consider the surface, or some place way up in the atmosphere. It's just supremely dangerous, no matter where you look.

To get a crew to go there to live permanently, you would have to force them at gunpoint, on pain of death. As far as I understand your politics, such a thing would be anathema to you. So why bother with this?

There is very little to be learned there, or to be recovered there, until we have some VERY serious terraforming technologies very well in-hand. That will not be for multiple centuries.

Until then, what is the point in even looking at this?

GW

Antius · 2016-05-18 05:43:42

It has a certain romantic value to those of us that remember the cloud city on Empire Strikes Back :-)

But it's hard to see why anyone would volunteer to go or what the economic imperitive would be. Sure, you can build stuff at ambient pressures and temperatures, but just about everything you use has to be imported. And what can you export that would be valuable enough to pay for it all? With Mars we have the same problem, but to a lesser extent. Survival is much easier and with enough tools and people a base could be reasonably self-sufficient. But what do you export to pay for the stuff you need? Deuterium? Plenty of that on Earth. Food? Easier to grow that on Earth. Rare metals?

Terraformer · 2016-05-18 07:08:09

Why do people live anywhere? If it's cheap enough, someone will try it.

What Venus needs, really, is a lot of water to be dumped on it. Enough that the clouds are water clouds, not sulphuric acid, and such that plant life can grow in the open air.

Mars doesn't really have anything to offer Terra trade wise. The asteroids do, but I don't think Mars has anything that's not much more abundant and accessible on Terra. The only economic reason to go to Mars is real estate development.

Tom Kalbfus · 2016-05-19 10:25:58

GW Johnson wrote:

Tom:
I do NOT understand this seeming obsession you have with sending humans to live at Venus. The place is a pretty good approximation to the Biblical descriptions of Hell.
No one in their right mind would ever volunteer to go there and live, not until we can terraform the place into something more Earth-like. That outcome doesn't matter whether you consider the surface, or some place way up in the atmosphere. It's just supremely dangerous, no matter where you look.
To get a crew to go there to live permanently, you would have to force them at gunpoint, on pain of death. As far as I understand your politics, such a thing would be anathema to you. So why bother with this?
There is very little to be learned there, or to be recovered there, until we have some VERY serious terraforming technologies very well in-hand. That will not be for multiple centuries.
Until then, what is the point in even looking at this?
GW

The secret to successful investing is buy low and sell high. Mars is a more sought after property. If humans colonize it, chances are there will be international borders between a number of different colonizers. The thing about Venus is you get a lot more planet, the planet has a nasty atmosphere, but down to its core, it is a lot like Earth. If you go by physical characteristics, as opposed to surface characteristics, Venus is more Earth like, it has an Earthlike gravity, while Mars' 0.38-G is a little worrying, humans will in someway have to adapt to that and become "Martians". Venus on the other hand can be made a lot more Earthlike, the fact that its rotation is wrong is of little concern, we just pull the shades around the planet, and harvest some solar energy in the process, and then provide our own light to simulate the 24-hour day/night cycle that we humans are used to, the shades will also provide the electricity to generate an artificial magnetosphere around the planet to deflect the solar wind. The planet's years is too short, we can fix that too, just as we would do with the too long day. If you stood on the surface of a fully terraformed Venus, it would be hard to tell you were not on Earth, it could be a second Earth in fact.

I think if you are to terrform Venus, you must do so in incremental steps, one way to start would be by building a single space elevator from the asteroid Aten.

As you can see by its orbit, it goes outside of Earth orbit and gets very close to Venus orbit. I think with an orbital nudge, it can be made to orbit Venus.

https://en.wikipedia.org/wiki/2062_Aten

As you can see by this entry, it has an average diameter of 1.1 km, and a mass of 7.6×10¹¹ kg (760 million tons). It seems like an object that can be moved. The asteroid that wiped out the dinosaurs was said to be about 5 km in diameter. so some atmospheric grazing might slow it into orbit, and if some of it hits Venus, so what no one lives there, we'd want to recover most of the asteroid though to be used in construction of the space elevator. The trick is most asteroids are piles or rubble, so an atmospheric grazing might create several satellites in elliptical orbits around Venus as well as several new impact craters on Venus' surface.

Tom Kalbfus · 2016-05-19 10:34:24

Antius wrote:

It has a certain romantic value to those of us that remember the cloud city on Empire Strikes Back :-)
But it's hard to see why anyone would volunteer to go or what the economic imperitive would be. Sure, you can build stuff at ambient pressures and temperatures, but just about everything you use has to be imported. And what can you export that would be valuable enough to pay for it all? With Mars we have the same problem, but to a lesser extent. Survival is much easier and with enough tools and people a base could be reasonably self-sufficient. But what do you export to pay for the stuff you need? Deuterium? Plenty of that on Earth. Food? Easier to grow that on Earth. Rare metals?

.
The United States doesn't live or die by its exports, as far as exports are concerned, there is solar energy. Venus is in a stable nearly circular orbit which provides constant access to Solar Energy that is more available than from Earth. Venus atmosphere can decelerate asteroids into its orbit, and there is plenty of solar energy for mining and industrial manufacture on orbit around Venus, and the 24-hour orbit zone will be a very popular orbit, as humans are used to a 24-hour day. From this industrialization, you can construct tethers that sometime dip into the atmosphere to extract valuable gases. the tether ends would travel at relative velocities attainable by jet engines. I think laser jets or nuclear powered jets would work best in this atmosphere. The cables can be retracted to avoid atmospheric drag when not mining the atmosphere or picking up cargo or passengers.

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#1 2016-05-15 14:10:08

The Atmosphere of Venus as a place to live

#2 2016-05-15 16:38:59

Re: The Atmosphere of Venus as a place to live

#3 2016-05-15 20:26:13

Re: The Atmosphere of Venus as a place to live

#4 2016-05-16 13:39:17

Re: The Atmosphere of Venus as a place to live

#5 2016-05-17 05:09:53

Re: The Atmosphere of Venus as a place to live

#6 2016-05-17 16:38:52

Re: The Atmosphere of Venus as a place to live

#7 2016-05-18 05:43:42

Re: The Atmosphere of Venus as a place to live

#8 2016-05-18 07:08:09

Re: The Atmosphere of Venus as a place to live

#9 2016-05-19 10:25:58

Re: The Atmosphere of Venus as a place to live

#10 2016-05-19 10:34:24

Re: The Atmosphere of Venus as a place to live

#11 2018-09-18 16:59:09

Re: The Atmosphere of Venus as a place to live

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