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This topic comes up a lot and I know it excites investors, but I have yet to see a viable plan for kick-starting the magnetic field on Mars. No magnetic field

This topic comes up a lot and I know it excites investors, but I have yet to see a viable plan for kick-starting the magnetic field on Mars. No magnetic field means no way to have an atmosphere, water or life and everyone has to stay in caves or incredibly durable modules indefinitely. The only O2 and H2O is what you bring with you or produce in the modules. The only reason I could see doing this is if we knew of impending extinction events coming to earth that would pass quickly and then we could return and re-populate. Is there another reason to colonize a dead planet? Are we trying to find a root cause for something and need a team to stick around longer than a regular mission time-frame?

russdill 7y ago
A lot of people get fooled into thinking that because Mars lacks an atmosphere due to a lack of a magnetic field, a magnetic field is required to have an atmosphere. The atmosphere was stripped away from Mars over hundreds of millions of years. If you could somehow restore the atmosphere today, it would remain just fine over any reasonable human timescales. Giving Mars at atmosphere is of course very difficult.
- goatlover 7y ago
  The magnetic field is needed to protect life on Mars from radiation. It's one of the bigger problems in terraforming the planet.
  - russdill 7y ago
    The atmosphere is what blocks radiation, not the magnetosphere.
    - goatlover 7y ago
      https://science.nasa.gov/heliophysics/focus-areas/magnetosphere-ionosphere https://science.nasa.gov/heliophysics/focus-areas/magnetosph...
      - russdill 7y ago
        That's a pretty simplistic explanation. If you look at the details, the magnetosphere is protecting the atmosphere. Take each kind of radiation in turn. X-Rays: The magnetosphere has no effect UV: The magnetosphere has no effect Cosmic rays: While both the Earth's magnetic field and the sun's magnetic deflect some cosmic rays, the Earth's atmosphere is mostly opaque to cosmic rays. Solar wind/coronal mass ejections: The Earth's magnetic field does block these, but if it wasn't present, the atmosphere would block them (but of course be slowly stripped away in the process) The fact that the magnetosphere does deflect some particles but isn't what makes life on Earth possible (other than protecting the atmosphere) is made most clear by the ISS being well within the magnetosphere but still receiving hundreds of times the amount on Earth.
        srajabi 7y ago
        But if we had the artificial magnetosphere and then populated the atmosphere we would get similar effects to Earth's protection?
        russdill 7y ago
        You're never going to get the same atmosphere on Mars vs Earth. Not only are you going to need to make a lot of tradeoffs with respect to gas content (eg, that much nitrogen is going to be very difficult to find/relocate) but the same amount of atmospheric pressure is going to take a larger mass of atmosphere since there is less gravity. So it really is a hard question to answer since to answer it you'd need to know what kind of atmosphere Mars would have.
        anticensor 7y ago
        You could replace some of nitrogen by argon to defeat pressure issues.
jkqwzsoo 7y ago
Your statement is a little hard to refute because I don’t know what you’ll admit as “viable”, but here’s a recent proposal which doesn’t require the magnetosphere actually being located on Mars: https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmo... And I guarantee you that this isn’t the only proposal that has been worked out.
m4rtink 7y ago
Mars still has some useful properties when compared to Luna or asteroid. It mostly relates to having quite a low gravity, but still having a thin atmosphere. We really don't have anything else suitable with these properties in reach (Earth has high gravity, Venus is effectively hell). The atmosphere is very thin, yet should be enough to get rid of most micrometeorites (a possible isue on lunar surface). Also thanks to the atmosphere, you can do various orbital maneuvers (aero-capture, aaero.breaking, aero assisted plane changes, etc.) that are not possible on a body without atmosphere. IT even makes some very specific aircraft designs work. Also with an atmosphere, you get less insane temperatures, you can mine it for CO2 for fuel and other uses. All in all, Mars is a frozen desert, but still a very useful frozen dessert providing many benefits in comparison to a barren rock floating in space.
srajabi 7y ago
It's possible to have an artificial magnetosphere with current technology: https://www.hou.usra.edu/meetings/V2050/pdf/8250.pdf https://www.hou.usra.edu/meetings/V2050/pdf/8250.pdf Theoretically at some point it should be possible to make this somewhat permanent with minimal maintenance. Depending on technology it could go from a station that lasts a hundred years to millions of years.

russdill 7y ago

A lot of people get fooled into thinking that because Mars lacks an atmosphere due to a lack of a magnetic field, a magnetic field is required to have an atmosphere. The atmosphere was stripped away from Mars over hundreds of millions of years. If you could somehow restore the atmosphere today, it would remain just fine over any reasonable human timescales. Giving Mars at atmosphere is of course very difficult.

goatlover 7y ago
The magnetic field is needed to protect life on Mars from radiation. It's one of the bigger problems in terraforming the planet.
- russdill 7y ago
  The atmosphere is what blocks radiation, not the magnetosphere.
  - goatlover 7y ago
    https://science.nasa.gov/heliophysics/focus-areas/magnetosphere-ionosphere https://science.nasa.gov/heliophysics/focus-areas/magnetosph...
    - russdill 7y ago
      That's a pretty simplistic explanation. If you look at the details, the magnetosphere is protecting the atmosphere. Take each kind of radiation in turn. X-Rays: The magnetosphere has no effect UV: The magnetosphere has no effect Cosmic rays: While both the Earth's magnetic field and the sun's magnetic deflect some cosmic rays, the Earth's atmosphere is mostly opaque to cosmic rays. Solar wind/coronal mass ejections: The Earth's magnetic field does block these, but if it wasn't present, the atmosphere would block them (but of course be slowly stripped away in the process) The fact that the magnetosphere does deflect some particles but isn't what makes life on Earth possible (other than protecting the atmosphere) is made most clear by the ISS being well within the magnetosphere but still receiving hundreds of times the amount on Earth.
      - srajabi 7y ago
        But if we had the artificial magnetosphere and then populated the atmosphere we would get similar effects to Earth's protection?
        russdill 7y ago
        You're never going to get the same atmosphere on Mars vs Earth. Not only are you going to need to make a lot of tradeoffs with respect to gas content (eg, that much nitrogen is going to be very difficult to find/relocate) but the same amount of atmospheric pressure is going to take a larger mass of atmosphere since there is less gravity. So it really is a hard question to answer since to answer it you'd need to know what kind of atmosphere Mars would have.
        anticensor 7y ago
        You could replace some of nitrogen by argon to defeat pressure issues.

jkqwzsoo 7y ago

Your statement is a little hard to refute because I don’t know what you’ll admit as “viable”, but here’s a recent proposal which doesn’t require the magnetosphere actually being located on Mars: https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmo... And I guarantee you that this isn’t the only proposal that has been worked out.

m4rtink 7y ago

Mars still has some useful properties when compared to Luna or asteroid. It mostly relates to having quite a low gravity, but still having a thin atmosphere. We really don't have anything else suitable with these properties in reach (Earth has high gravity, Venus is effectively hell). The atmosphere is very thin, yet should be enough to get rid of most micrometeorites (a possible isue on lunar surface). Also thanks to the atmosphere, you can do various orbital maneuvers (aero-capture, aaero.breaking, aero assisted plane changes, etc.) that are not possible on a body without atmosphere. IT even makes some very specific aircraft designs work. Also with an atmosphere, you get less insane temperatures, you can mine it for CO2 for fuel and other uses. All in all, Mars is a frozen desert, but still a very useful frozen dessert providing many benefits in comparison to a barren rock floating in space.

srajabi 7y ago

It's possible to have an artificial magnetosphere with current technology: https://www.hou.usra.edu/meetings/V2050/pdf/8250.pdf https://www.hou.usra.edu/meetings/V2050/pdf/8250.pdf Theoretically at some point it should be possible to make this somewhat permanent with minimal maintenance. Depending on technology it could go from a station that lasts a hundred years to millions of years.