Would tidally locking Venus freeze the CO2 on the dark side?

[Eclipse]

Hi all,
some have proposed that we give up trying to terraform Venus because of its terrible atmosphere, and instead try chucking tens of thousands of giant asteroids and Kuiper belt objects at it not to speed it up to an Earth day, but to tidally lock it. The hope is that the bright side would be a great place for solar power, the twilight zone in the middle would be a great place to build domes and habitats to mine all the Venusian mineral wealth, and the dark side would be where all that horrible CO2 and sulfur rained down. The problem is, we don't seem to have agreement on whether or not it would get cold enough back there to freeze CO2. I'm no physicist but it appears to me that if the atmosphere on Venus *already* shoots through the dark side in 2 days without freezing in the existing 116 day long rotation, then it's not going to cool even if one spot becomes permanently dark. For purposes of atmospheric circulation, a 90bar CO2 acid atmosphere shooting around the whole planet in 4 days seems to laugh at 116 day rotation. Isn't the atmosphere just going to continue doing that even if one place became permanently dark? Does anyone have the physics to answer this? The papers I was trying to read in google scholar were way above my head.

[Moontanman]

On 7/23/2017 at 3:47 AM, Eclipse said:

Hi all,
some have proposed that we give up trying to terraform Venus because of its terrible atmosphere, and instead try chucking tens of thousands of giant asteroids and Kuiper belt objects at it not to speed it up to an Earth day, but to tidally lock it. The hope is that the bright side would be a great place for solar power, the twilight zone in the middle would be a great place to build domes and habitats to mine all the Venusian mineral wealth, and the dark side would be where all that horrible CO2 and sulfur rained down. The problem is, we don't seem to have agreement on whether or not it would get cold enough back there to freeze CO2. I'm no physicist but it appears to me that if the atmosphere on Venus *already* shoots through the dark side in 2 days without freezing in the existing 116 day long rotation, then it's not going to cool even if one spot becomes permanently dark. For purposes of atmospheric circulation, a 90bar CO2 acid atmosphere shooting around the whole planet in 4 days seems to laugh at 116 day rotation. Isn't the atmosphere just going to continue doing that even if one place became permanently dark? Does anyone have the physics to answer this? The papers I was trying to read in google scholar were way above my head.

 

I would have to say no, the atmosphere of Venus is far too thick to allow that to happen. In fact I have seen some writings by Astronomers that indicate this would be true even for planets with thinner atmospheres. If you are interested I'll see if I can get you a link. Sun shades in orbit would help as would a much shorter day. Technically, at least according to some authorities, Venus is in the habitable zone.. barely. The long day might have contributed to the runaway greenhouse effect. Shade it, speed up its rotation, add lots of water, a magnetic field, and maybe a largish moon and you would have something.   

 

Some sources seem to think that floating balloon cities would be better since an oxygen nitrogen mix is lifting gas on Venus... 

 

Isaac discusses this from around 25:25 in this video.

 

 

 

Edited July 25, 2017 by Moontanman

[Area54]

Hello Eclipse, when I read only the title of your thread my immediate thought was "No way" because of the high and persistent wind velocity. I see you had exactly the same thought. That said, I should like to see some comprehensive modelling to convince me that it was not a viable option. I suspect the work hinted at by Moontanman may have been somewhat simplified and limited in scope, as most early modelling of any problem necessarily is.