4 ms·

Also, the lack of a magnetic field to protect from solar radiation.

by goatlover 7y ago

rusk 7y ago
I think this is the crucial point. When I heard this I gave up hope.
- garmaine 7y ago
  Why? You’re not going to be spending most of your time out on suits anyway. Put some sandbags on the roof.
  - jacobush 7y ago
    Because the atmosphere will be stripped away by the Sun. But see comment about generating a magnetic field.
    - wongarsu 7y ago
      Yes, over billions of years the atmosphere will be stripped away. But the process is way too slow for us to worry about.
      - jacobush 7y ago
        https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmo... NASA estimates, given Mars was given a magnetic field, it would only take a century (give or take) to start to melt oceans. So your estimate seems to be off by a bit.
        garmaine 7y ago
        Did you reply to the wrong comment?
        jacobush 7y ago
        No - it means that the solar wind is affecting the atmosphere enough that a greenhouse effect on Mars is not getting started, even though it could if there was a magnetic field on the planet. This means the solar wind effect is not negligible. An artificial magnetic field plus other means could have a drastic and extremely rapid (in geologic terms, hundreds of years) effect on Mars climate.
- itronitron 7y ago
  This article discusses how a magnetic field can be generated to protect Mars and it's atmosphere from solar winds.
cstross 7y ago
There might be mitigation strategies. First step: colonize Valles Marineris. (It's as much as 7km below mean surface level, so the atmosphere is going to be considerably thicker at the bottom than at surface level: for reference, that's the same height as Mount Everest, although due to the difference in gravity the scale height is higher, meaning you don't get as good a pressurization increase as you would on Earth). Second step: build residencies by drilling horizontal tunnels into the cliff walls and pressurizing the entrances. Third step: throw large mylar domes (or even roof) over the floor of the canyon and actively compress the air down there to get it up to a temperature at which crops will grow. Scavenge oxygen produced by photosynthesis from the mostly-CO2 atmosphere using cold traps. (Your colonists aren't exposed to the solar and cosmic radiation because they're living under a couple of km of rock, and their crops are under almost double ambient atmospheric pressure even before you add active pressurization to the farms.) Note that Vales Marineris is 4000km long and up to 200km wide in places. It's huge -- ISTR hearing that it has roughly the same land area as Germany (but can't find the source right now).
- JohnJamesRambo 7y ago
  Your comment made me even less hopeful we can colonize Mars. What are the benefits that would drive such colonization? On Earth there were rich resources driving human expansion into new areas. This Mars expansion would be like humans repeatedly trying to live in the Atacama desert but orders of magnitude even more harsh. Mars is constantly trying to kill you, and is fantastically expensive due to the distance to Mars and cost to transport things there. What reason would we have to make us attempt it?
  - pvaldes 7y ago
    > Mars is constantly trying to kill you, And the Earth could be trying to do the same in 100 years.
    - cglace 7y ago
      You believe earth and mars will be on par in terms of habitability in 100 years? If I were confident I would live that long I would take that bet.
DennisP 7y ago
Radiation on Mars is at a level similar to the background radiation in Ramsar, Iran. People there have normal life expectancy and cancer rates. https://caseyhandmer.wordpress.com/2019/10/20/omg-space-is-full-of-radiation-and-why-im-not-worried/ https://caseyhandmer.wordpress.com/2019/10/20/omg-space-is-f...

Also, the lack of a magnetic field to protect from solar radiation.

rusk 7y ago

I think this is the crucial point. When I heard this I gave up hope.

garmaine 7y ago
Why? You’re not going to be spending most of your time out on suits anyway. Put some sandbags on the roof.
- jacobush 7y ago
  Because the atmosphere will be stripped away by the Sun. But see comment about generating a magnetic field.
  - wongarsu 7y ago
    Yes, over billions of years the atmosphere will be stripped away. But the process is way too slow for us to worry about.
    - jacobush 7y ago
      https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmo... NASA estimates, given Mars was given a magnetic field, it would only take a century (give or take) to start to melt oceans. So your estimate seems to be off by a bit.
      - garmaine 7y ago
        Did you reply to the wrong comment?
        jacobush 7y ago
        No - it means that the solar wind is affecting the atmosphere enough that a greenhouse effect on Mars is not getting started, even though it could if there was a magnetic field on the planet. This means the solar wind effect is not negligible. An artificial magnetic field plus other means could have a drastic and extremely rapid (in geologic terms, hundreds of years) effect on Mars climate.
itronitron 7y ago
This article discusses how a magnetic field can be generated to protect Mars and it's atmosphere from solar winds.

cstross 7y ago

There might be mitigation strategies. First step: colonize Valles Marineris. (It's as much as 7km below mean surface level, so the atmosphere is going to be considerably thicker at the bottom than at surface level: for reference, that's the same height as Mount Everest, although due to the difference in gravity the scale height is higher, meaning you don't get as good a pressurization increase as you would on Earth). Second step: build residencies by drilling horizontal tunnels into the cliff walls and pressurizing the entrances. Third step: throw large mylar domes (or even roof) over the floor of the canyon and actively compress the air down there to get it up to a temperature at which crops will grow. Scavenge oxygen produced by photosynthesis from the mostly-CO2 atmosphere using cold traps. (Your colonists aren't exposed to the solar and cosmic radiation because they're living under a couple of km of rock, and their crops are under almost double ambient atmospheric pressure even before you add active pressurization to the farms.) Note that Vales Marineris is 4000km long and up to 200km wide in places. It's huge -- ISTR hearing that it has roughly the same land area as Germany (but can't find the source right now).

JohnJamesRambo 7y ago
Your comment made me even less hopeful we can colonize Mars. What are the benefits that would drive such colonization? On Earth there were rich resources driving human expansion into new areas. This Mars expansion would be like humans repeatedly trying to live in the Atacama desert but orders of magnitude even more harsh. Mars is constantly trying to kill you, and is fantastically expensive due to the distance to Mars and cost to transport things there. What reason would we have to make us attempt it?
- pvaldes 7y ago
  > Mars is constantly trying to kill you, And the Earth could be trying to do the same in 100 years.
  - cglace 7y ago
    You believe earth and mars will be on par in terms of habitability in 100 years? If I were confident I would live that long I would take that bet.

DennisP 7y ago

Radiation on Mars is at a level similar to the background radiation in Ramsar, Iran. People there have normal life expectancy and cancer rates. https://caseyhandmer.wordpress.com/2019/10/20/omg-space-is-full-of-radiation-and-why-im-not-worried/ https://caseyhandmer.wordpress.com/2019/10/20/omg-space-is-f...