New Mars Forums

I thought I'd post this in Terraforming Venus thread but it's probably worth a new thread.

Venus is very attractive because of its size and likeness to Earth but Venus may not 3rd or 4th, which people will actually try to colonise and terraform.

IMHO, both Luna and Mars will always be the 1st priority for settlement, followed by Callisto and Ganymede, not by Venus. Settling on Jovian moons seems less costly despite the distance. Even Titan and other Saturnian natural satellites - I mean Tethys, Dione, Rhea and Iapetus.

In my opinion, sooner or later larger planetary bodies from Mercury to Saturn will be settled.
Candidates: Mercury, Venus, Luna, Mars, Callisto, Ganymede, Europa, Titan, Tethys, Dione, Rhea and Iapetus.

What do you think realistically would happen (not what you wish to happen) and in which order?

1. Luna and Mars - always in parallel, even if you're in love with Mars, you will agree, our Moon is not ignored and won't in the future.
2. What's next? Mercury and Venus seem very hard.
Perhaps, the next objects for colonisation will become Callisto and/or Ganymede. Perhaps followed by Europa.
3. I am not so sure but I think it's not Venus or Mercury again. I see some terraforming efforts on Titan followed by any of Tethys, Dione, Rhea and Iapetus.
4. Mercury or Venus.

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Sorry for long breaks. Terraforming still excites me but I don't see much happening in this direction (frustrating!) and I haven't gained any new knowledge since the time I posted more intensively.

Venus is closer to Ceres than any outer planet, unless you mean the source of carbon is other asteroids, Earth/Luna or Mars.

Ceres's distance from the Sun: 381,419,582 - 447,838,164 km. Venus 108 mln km. Jupiter: 740,573,646 - 816,520,751 km.

Water is practically absent on Venus. It can get it only if we give it some and we won't give more than it needs to reach the balance. Besides, the planet is pretty flat on average. The oceans may get only half a km maximum.

Venus with an earth-like atmosphere would have an average annual temperature of about 20-25 C (4C on Earth). I hope these estimations are correct, otherwise the sunshade should be much bigger and cover not just the hottest equatorial areas. But that's average, it could become really hot during a long 2-month day. Thicker atmosphere will somewhat increase the greenhouse effect, which we need for circulation and we need a better than we have on Earth and that will reduce day and night temperature difference. Nitrogen won't have the same effect as CO2, which we want to bring down to minimum. I suggest 95% - 5% ratio (nitrogen vs oxygen) vs 70% - 30% on Earth. Without the sunshades days would become too hot and a runaway would begin.

Mars, hm, I think may not need a thicker or thinner atmosphere than Earth but we want more gases with the greenhouse effect, so the atmosphere structure must be different there (I don't want to digress).

Magnetic fields can be constructed without changing rotation speed of a planet, IMHO. It would require a lot of energy, though. There's abundance of sunlight on Venus, which can be used to produce electricty and it would require a lot of initial work.

Final atmosphere structure - volume and constituents, the size of water surface and depth of the global ocean, the size and postioning of the shade(s), artificial fields will all require thorough simulations.

Venus receive 1.9 of the solar energy and is just outside the livable zone, if not on the edge or inside it.

I agree that Venus is much more challenging to terraform than Mars but there should be more attempts and investigations in this area. I think, if people start doing it, it will eventully become clearer, which path is correct and which method is more efficient.

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I like these pages from a Canadian terraformers's site. They also have pages on Venusian terraforming.

http://society.terraformers.ca/

1 bar is good on Earth but it's hard to estimate what would be ideal for planets with different conditions. I think Venus needs a thicker than Earth atmosphere but much thinner as it is now.

This would soften the effect of too long nights and days and reduce radiation the Sun is 90% stronger on Venus - a thick layer of nitrogen/oxygen would give more protection. 3 bars is my estimate of maximum people/animals can get used to but this is an arguable point.

A thicker atmosphere with proper winds will spread the temperatures more equally on the surface, at the same time protecting the surface from excessive light.

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On the hollowed out asteroids (it's not my idea but I embraced it): alternatively, we could consider a permanent satellite made out of a hollowed out astreoid, which could take all the excessive gases from Venus because shipping to other planets may be still expensive. The job of getting an asteroid onto Venusian orbit is difficult but possible with modern technology.

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Magnetic fields were discussed may times on Mars terraformation topics. I think, they are feasible, Venus would need a much more massive one.

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I am against permanent huge mirrors but all for permanent partial shade, which would block some of the light in the hottest areas. Spinning a large planet is not feasible, it's easier to adjust to new enviornment and create a better climate by a proper mix of gases; use of sunshades and artificial magnetic fields.

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The key to cooling Venus is getting rid of the excessive CO2 (not spinning the planet or shifting further from the Sun - these ideas are unrealistic). Venus with no atmosphere will be heaps colder than it is now! Earthlike atmosphere on Venus with a sunshade may produce amazing results, I want to see some calcs on that. I know someone experimented with that.

Has anyone considered using hollowed out asteroids (around 50 km in diameter) to ship excessive compressed gases out of Venus? It will take a while still.

Realistically what can be achieved by humans is reducing the atmosphere to 2.5 - 3 bars (95% nitrogen, 5% oxygen), creating a powerful magnetic field (more powerful than that on Earth) partial sunshade, no change to rotation - I don't think there are realistic plans to change its rotation.

Maybe not related but I want to add a point that I read recently about Venus - want to add this into my future document - my selection of ideas about terraforming Venus.

Venus with a 3 bar nitrogen/oxygen atmosphere (90%/10%) would need about 10% of Earth water only to cover 80% of its surface - due to the flatness of most of its land. That is if the Venusian topography stays unchanged. Mostly shallow oceans (500 m at deepest points) would still perfectly balance the hydrological cycle on the planet - maybe even better than on Earth - provided Venus has also a strong magnetic field - similar or stronger than Earth's. The boiling point of water with 3 bars would be at about 150 C.

On Mars we have an opposite effect - where deep waters would cover 25 to 40% of the surface - due to the big difference between the highest and lowest points.

Approximate difference between the highest and lowest points:

Venus: 10 km
Earth: 20 km
Mars: 40 km

Although it's 10 km on Venus - the 3/5 of the planet has only 0.5 km between high and low! It's really flat!

People would need to be very careful with water resources on Venus - keeping the waters clean would be the highest priority.

I can't wait when we get a clear image of the topography/surface of Titan. I read NASA was going to - the same way it was done for Venus. Not sure when, though.

I thought the topic was about terraforming Mars.

Wrong way go back. :sleep:

We'll see how good it gets, Georgi - too early to talk about publishing in a magazine but who knows... It's a good idea.

To post an image here - you need to have that image somewhere on a website - you can find free hosts and publish you web pages and images there. In this forum, when you post you'll see the "image" button.

Hi Georgi,

Interesting topic. Pity, I am too busy these days.

I didn't have any luck with my search for Venus climate simulation pages. Although, I found this:

http://www.users.globalnet.co.uk/~mfogg/simul.htm]The Terraforming Simulator Project

http://www.users.globalnet.co.uk/~mfogg … m.html]The Actual Simulator You'll need Java run-time environment.

This simulation was used to calculate what variables should be achieved to terraform Mars (not new) but I'm posting in case someone hasn't seen it.

Agree with all the points, only with the Lunar climate - not sure - if we get the coriolis effect because of the slow rotation then the winds will go East-West-East and the poles remain cold but the temperature will spread evenly along the latitudes.

As for the Venus terraforming - could you help to prepare a summary that I could send for discussion/comments to a couple of people - Gerald Nordley, Paul Birch and people who contributed to the Venus discussion. The former (G.N.) replied to me and we had a discussion about Mercury terraformation. The latter (P.B.) wasn't very enthusiastic but we may try to get his help anyway. If we get some support on the key points the paper will have much better value. I mean, this hasn't been discussed in details in any page I saw - non-traditional terraformation of Venus - no spinning up, no permanent shades (after terraforming not during!), higher pressure, hotter and wetter climate but here we are - a realistic method. The major big expenditures will be on building chimneys, shuttles to remove gas, magnetic fields, temporary sun shields, technology to bring water and oxygen, clean the remaining 3 bars of the atmosphere.

How good is it going to be remains to be proved and discussed - it's all based on the assertion that Venus is still in the habitable thermal zone (180% of the Earth) and the correct balance of atmosphere-hydrosphere composition and amount will give us a tolerable climate - different from Earth but the one life could adjust to - the 3 bars atmosphere required to give more albedo, keep the temperatures even on the lit and the dark side (having 56 Earth days long days and nights), better radiation protection combined with installed magnetic fields.

Another point on the topic is that having a larger (taller) mass of the atmosphere on the smaller bodies including Mars and the Moon makes almost all elevation levels habitable! Think about it: if Martian atmosphere has to be 3 times higher than Earth to achieve one bar - there won't be much difference in pressure between 0 sea level and the top of the largest volcanoes. Olympus Mons could even have a huge lake in its caldera. (I can foresee angry comments from the Reds - leave Olympus Mons alone!)

Maybe the same reason you keep spelling the word Martian with an S, not with a T, they just like it that way. Only joking, Cindy.     

It's great! I am all for cooperation.

Well, it is always colder on the poles, as with any planet, including Earth. Lunar average temperature may get close to Earth's average, so will the lowest and the highest temperatures. The poles are the storages of fresh water as ice - the most stable parts in terms of climate (not so much difference between day and night temperatures, compared to the rest of the Moon) and this where the climate will be really similar to Earth's poles with penguins and polars bears, etc. I don't see any need to put mirrors around the poles, the colder the better atmosphere retention.