3 ms·

I'm not very knowledgeable, but couldn't we wrap the space suits in tinfoil or something?

by Andrex 4y ago

idlewords 4y ago
This works for lower energy particles (like protons from the sun), but for heavy ions partial shielding makes the problem worse than not having shielding at all, the small number that hit the metal instead of passing through create a shower of damaging secondary radiation. Effectively shielding people from cosmic rays requires either a thick atmosphere, a couple meters of soil, or really thick slabs of metal. The best solution on Mars might be to build a shelter inside a cave or lava tube, but then you run up afoul of international treaty obligations to not contaminate these sensitive environments. The short answer to your question is "yes, but the foil has to be three feet thick."
- Retric 4y ago
  I mostly agree with that but you don’t need to hand wave as much. The atmosphere of mars is roughly equivalent too 2 inches of soil if the source is directly overhead and 3 inches at a 45 degree angle, but far more than that at low angles. Anything below the horizon is blocked by the surface of Mars, so you end up with well over 50% shielding from cosmic rays vs the trip to Mars. Being further from the sun is also beneficial. You definitely want to live and work underground on Mars or at minimum below a large water tank, but even just landing in a valley can noticeably reduce radiation exposure as the mountains block portions of the sky so too do they block a portion of cosmic rays.
  - idlewords 4y ago
    I think you have this backwards; GCR flux increases with distance from the sun.
    - Retric 4y ago
      For GCR, but not total radiation exposure. Cosmic rays are a combination of solar energetic particles and GCR. Though this is dependent on how active the sun is: “If the instrument had been taking measurements on Mars during the comparable period of the solar-activity cycle about 11 years ago, it would probably have seen eight events in 300 sols, contributing an unknown but certainly significantly higher amount to the overall dose.” And of course if Mars was closer to the sun these numbers would be significantly higher. https://www.nasa.gov/jpl/msl/mars-rover-curiosity-pia17600.html https://www.nasa.gov/jpl/msl/mars-rover-curiosity-pia17600.h...
      - idlewords 4y ago
        I've been talking since the top of the thread about the heavy ion component of galactic cosmic radiation, not space radiation in general.
        Retric 4y ago
        I realize. That line was simply pointing out that while being further from the sun is a net negative in terms of GCR it’s a net positive in terms of total radiation exposure.

I'm not very knowledgeable, but couldn't we wrap the space suits in tinfoil or something?

by Andrex 4y ago

I'm not very knowledgeable, but couldn't we wrap the space suits in tinfoil or something?

This works for lower energy particles (like protons from the sun), but for heavy ions partial shielding makes the problem worse than not having shielding at all, the small number that hit the metal instead of passing through create a shower of damaging secondary radiation. Effectively shielding people from cosmic rays requires either a thick atmosphere, a couple meters of soil, or really thick slabs of metal. The best solution on Mars might be to build a shelter inside a cave or lava tube, but then you run up afoul of international treaty obligations to not contaminate these sensitive environments. The short answer to your question is "yes, but the foil has to be three feet thick."

Retric 4y ago
I mostly agree with that but you don’t need to hand wave as much. The atmosphere of mars is roughly equivalent too 2 inches of soil if the source is directly overhead and 3 inches at a 45 degree angle, but far more than that at low angles. Anything below the horizon is blocked by the surface of Mars, so you end up with well over 50% shielding from cosmic rays vs the trip to Mars. Being further from the sun is also beneficial. You definitely want to live and work underground on Mars or at minimum below a large water tank, but even just landing in a valley can noticeably reduce radiation exposure as the mountains block portions of the sky so too do they block a portion of cosmic rays.
- idlewords 4y ago
  I think you have this backwards; GCR flux increases with distance from the sun.
  - Retric 4y ago
    For GCR, but not total radiation exposure. Cosmic rays are a combination of solar energetic particles and GCR. Though this is dependent on how active the sun is: “If the instrument had been taking measurements on Mars during the comparable period of the solar-activity cycle about 11 years ago, it would probably have seen eight events in 300 sols, contributing an unknown but certainly significantly higher amount to the overall dose.” And of course if Mars was closer to the sun these numbers would be significantly higher. https://www.nasa.gov/jpl/msl/mars-rover-curiosity-pia17600.html https://www.nasa.gov/jpl/msl/mars-rover-curiosity-pia17600.h...
    - idlewords 4y ago
      I've been talking since the top of the thread about the heavy ion component of galactic cosmic radiation, not space radiation in general.
      - Retric 4y ago
        I realize. That line was simply pointing out that while being further from the sun is a net negative in terms of GCR it’s a net positive in terms of total radiation exposure.