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I remember reading that Mars doesn't have a magnetic field like Earth's to protect it from solar wind, therefore the atmosphere mostly gets swept away. Is that

I remember reading that Mars doesn't have a magnetic field like Earth's to protect it from solar wind, therefore the atmosphere mostly gets swept away. Is that not the more difficult problem here? This debate seems to center on generating enough CO2, but that seems a bit irrelevant if it would just blow away. How would you even go about fixing the magnetic field of a planet?

bpodgursky 5y ago
https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html#:~:text=In%20essence%2C%20they%20suggested%20that,from%20solar%20wind%20and%20radiation https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmo.... > In answer to this challenge, Dr. Jim Green – the Director of NASA's Planetary Science Division – and a panel of researchers presented an ambitious idea. In essence, they suggested that by positioning a magnetic dipole shield at the Mars L1 Lagrange Point, an artificial magnetosphere could be formed that would encompass the entire planet, thus shielding it from solar wind and radiation.
tibbydudeza 5y ago
No problem - we just need to melt the outer core to get the dynamo effect - will only require 1 trillion nuclear bombs once we figure the technology to drill down to that depth.
- OmicronCeti 5y ago
  Perhaps that's the end-game for lord Musk's Boring Company
- TchoBeer 5y ago
  Can't tell how sarcastic this comment is
meepmorp 5y ago
It's all about the rate of loss. If it's 1% per year, that's probably not going to work; if it's 0.0001%, that's a different matter altogether. Everything is temporary in the long run.
- OmicronCeti 5y ago
  From the paper in the article: >"MAVEN has observed the Martian upper atmosphere for a full Martian year, and has determined the rate of loss of gas to space and the driving processes; 1–2 kg/s of gas are being lost." https://www.sciencedirect.com/science/article/pii/S0019103517306917 https://www.sciencedirect.com/science/article/pii/S001910351...
  - meepmorp 5y ago
    Oh, I was thinking in terms of the cost benefit of terraforming. If you magically make the planet's atmosphere 1 bar of co2, how long would that last at a usable level - say at or above 0.5 bar - assuming no replacement? If that's 10k years it's less appealing, but 1m years might be worth it.
FredPret 5y ago
Earth’s magnetic field comes from consisting of a massive ball of molten iron surrounded by layers of rock, soil, and, ultimately, monkeys. The critical component for the magnetic field (the molten iron ball) is hard to replicate.
- valuearb 5y ago
  The necessary magnetic field is actually easy to replicate.
jpollock 5y ago
That's probably a problem on billion year scales. I wonder what the annual loss would be.
- JoeAltmaier 5y ago
  Its estimated Mars had at atmosphere for the first billion years. But loss is not linear. The less you have, the faster it's eroded. So to rebuild it, might want to quickly get to a sustainable value before its blown away again? I favor crashing Saturn's icy asteroids into Mars to release gigatons of water vapor.
  - cogman10 5y ago
    Isn't it the reverse? The more atmosphere is present the faster it erodes away?
    - JoeAltmaier 5y ago
      Not according to the papers.
      - cogman10 5y ago
        Which papers? That's really counter intuitive to me. I'd expect that a higher atmosphere concentration would have a higher rate of loss because the solar wind would grab more of it. Does this mean that mars is losing atmosphere faster today than it did 500million years ago? That's really fascinating!
        JoeAltmaier 5y ago
        Can't find it now. Curiosity has an instrument to measure isotopes, which tells how its air chemistry changed over the aeons. It showed disparity in heavy vs light gasses trapped in rocks of different ages. Light gasses are lost first, so that gave a clock on atmosphere loss. And a profile of that loss over time. Here's a sunday-supplement summary I did find: https://science.time.com/2013/07/23/revealed-how-mars-lost-its-atmosphere/ https://science.time.com/2013/07/23/revealed-how-mars-lost-i...
m4rtink 5y ago
Build a worldhouse instead of full terraformation ? https://www.orionsarm.com/eg-article/484746e824a3a https://www.orionsarm.com/eg-article/484746e824a3a No need to worry about atmosphere loss & you can start incrementally and get usable land almost at only, not only after long years of terraformation.
- qayxc 5y ago
  Agreed. Para-terraforming is a criminally underrated concept. With "terraforming" you'd have the problem that dozens of generations would have to work their proverbial asses off without ever experiencing the fruits of their labour. Not exactly a strong suit of the human race. Another advantage of the world-house approach is the possibility to leave sites of interest as-is by not including them. With terraforming it's impossible to preserve select areas for scientific or cultural reasons.
andys627 5y ago
We can create a magnetosphere at Lagrange point between Mars and Sun that has a tail that would protected Mars from solar radiation. Radiation from other stars is still a problem I think? https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmo...
- rbanffy 5y ago
  True, but at least the magnetic field could redirect solar wind (or, at least, its protons) to impact head-on and replenish Martian hydrogen instead of pushing the atmosphere away.
valuearb 5y ago
The math is clear. A new atmosphere would take millions of years to get swept away.
- hinkley 5y ago
  Last math I saw suggested 100,000 years, but if we're still on Mars for that long and dealing with atmospheric bleed-off, we done fucked up already.
  - valuearb 5y ago
    Even if it’s only a hundred thousand years, we can set up a magnetic field in Mars orbit that would substantially reduce losses far easier than actually making the new atmosphere.
BurningFrog 5y ago
By that logic it's pointless to pump a tire, since the air will eventually leak out. Terraforming will in part be a permanent process. The atmosphere lost will have to be continually replaced. And that's fine.

bpodgursky 5y ago

https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html#:~:text=In%20essence%2C%20they%20suggested%20that,from%20solar%20wind%20and%20radiation https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmo.... > In answer to this challenge, Dr. Jim Green – the Director of NASA's Planetary Science Division – and a panel of researchers presented an ambitious idea. In essence, they suggested that by positioning a magnetic dipole shield at the Mars L1 Lagrange Point, an artificial magnetosphere could be formed that would encompass the entire planet, thus shielding it from solar wind and radiation.

tibbydudeza 5y ago

No problem - we just need to melt the outer core to get the dynamo effect - will only require 1 trillion nuclear bombs once we figure the technology to drill down to that depth.

OmicronCeti 5y ago
Perhaps that's the end-game for lord Musk's Boring Company
TchoBeer 5y ago
Can't tell how sarcastic this comment is

meepmorp 5y ago

It's all about the rate of loss. If it's 1% per year, that's probably not going to work; if it's 0.0001%, that's a different matter altogether. Everything is temporary in the long run.

OmicronCeti 5y ago
From the paper in the article: >"MAVEN has observed the Martian upper atmosphere for a full Martian year, and has determined the rate of loss of gas to space and the driving processes; 1–2 kg/s of gas are being lost." https://www.sciencedirect.com/science/article/pii/S0019103517306917 https://www.sciencedirect.com/science/article/pii/S001910351...
- meepmorp 5y ago
  Oh, I was thinking in terms of the cost benefit of terraforming. If you magically make the planet's atmosphere 1 bar of co2, how long would that last at a usable level - say at or above 0.5 bar - assuming no replacement? If that's 10k years it's less appealing, but 1m years might be worth it.

FredPret 5y ago

Earth’s magnetic field comes from consisting of a massive ball of molten iron surrounded by layers of rock, soil, and, ultimately, monkeys. The critical component for the magnetic field (the molten iron ball) is hard to replicate.

valuearb 5y ago
The necessary magnetic field is actually easy to replicate.

jpollock 5y ago

That's probably a problem on billion year scales. I wonder what the annual loss would be.

JoeAltmaier 5y ago
Its estimated Mars had at atmosphere for the first billion years. But loss is not linear. The less you have, the faster it's eroded. So to rebuild it, might want to quickly get to a sustainable value before its blown away again? I favor crashing Saturn's icy asteroids into Mars to release gigatons of water vapor.
- cogman10 5y ago
  Isn't it the reverse? The more atmosphere is present the faster it erodes away?
  - JoeAltmaier 5y ago
    Not according to the papers.
    - cogman10 5y ago
      Which papers? That's really counter intuitive to me. I'd expect that a higher atmosphere concentration would have a higher rate of loss because the solar wind would grab more of it. Does this mean that mars is losing atmosphere faster today than it did 500million years ago? That's really fascinating!
      - JoeAltmaier 5y ago
        Can't find it now. Curiosity has an instrument to measure isotopes, which tells how its air chemistry changed over the aeons. It showed disparity in heavy vs light gasses trapped in rocks of different ages. Light gasses are lost first, so that gave a clock on atmosphere loss. And a profile of that loss over time. Here's a sunday-supplement summary I did find: https://science.time.com/2013/07/23/revealed-how-mars-lost-its-atmosphere/ https://science.time.com/2013/07/23/revealed-how-mars-lost-i...

m4rtink 5y ago

Build a worldhouse instead of full terraformation ? https://www.orionsarm.com/eg-article/484746e824a3a https://www.orionsarm.com/eg-article/484746e824a3a No need to worry about atmosphere loss & you can start incrementally and get usable land almost at only, not only after long years of terraformation.

qayxc 5y ago
Agreed. Para-terraforming is a criminally underrated concept. With "terraforming" you'd have the problem that dozens of generations would have to work their proverbial asses off without ever experiencing the fruits of their labour. Not exactly a strong suit of the human race. Another advantage of the world-house approach is the possibility to leave sites of interest as-is by not including them. With terraforming it's impossible to preserve select areas for scientific or cultural reasons.

andys627 5y ago

We can create a magnetosphere at Lagrange point between Mars and Sun that has a tail that would protected Mars from solar radiation. Radiation from other stars is still a problem I think? https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmo...

rbanffy 5y ago
True, but at least the magnetic field could redirect solar wind (or, at least, its protons) to impact head-on and replenish Martian hydrogen instead of pushing the atmosphere away.

valuearb 5y ago

The math is clear. A new atmosphere would take millions of years to get swept away.

hinkley 5y ago
Last math I saw suggested 100,000 years, but if we're still on Mars for that long and dealing with atmospheric bleed-off, we done fucked up already.
- valuearb 5y ago
  Even if it’s only a hundred thousand years, we can set up a magnetic field in Mars orbit that would substantially reduce losses far easier than actually making the new atmosphere.

BurningFrog 5y ago

By that logic it's pointless to pump a tire, since the air will eventually leak out. Terraforming will in part be a permanent process. The atmosphere lost will have to be continually replaced. And that's fine.