4 ms·

That wouldn't do much good unless we can re-establish the magnetosphere.

meri_dian 9y ago
Ah yeah, forgot about that. And restarting the core dynamo seems pretty infeasible regardless or our technological capabilities.
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throwawayaway12 9y ago
I think it is still an open (and hotly debated) question on if planets need magnetospheres to retain an atmosphere.
- toomuchtodo 9y ago
  A magnetosphere is required to shield from charges particles and other harmful radiation.
  - deleted 9y ago
    [deleted]
- ethbro 9y ago
  * also, retain an atmosphere "over long enough timescales" From the MAVEN research papers I've read, we're talking ~5,000 metric tons / yr of atmosphere being stripped. Which is a lot, but not an insurmountable lot.
YokoZar 9y ago
Mars has isolated pockets of "mini magnetospheres" that are suitable enough to block charged particles. http://www.space.dtu.dk/english/Research/Universe_and_Solar_System/magnetic_field http://www.space.dtu.dk/english/Research/Universe_and_Solar_...
- maxk42 9y ago
  I think he was assuming the subject was terraforming. Without a magnetosphere, the atmosphere will keep being blasted off into space continuously, and it'll be impossible to terraform.
  - mkl 9y ago
    Continuously, but slowly, over very long time scales. Maintaining an atmosphere suitable for us is probably far easier than constructing it in the first place.
avz 9y ago
I don't think that's necessary. The loss of atmosphere by Mars may have been significant on the timescale of its five-billion-years history, but not on the timescale of a human settlement project. The mass of the Martian atmosphere is about 25 teratonnes [1]. According to the measurements by MAVEN, the rate of mass loss by Martian atmosphere due to solar wind is 100 g/s [2]. At this rate it would take 25e12 * 1000 * 1000 * 0.01 / 100 / 3600 / 24 / 365.25 = 79 million years for Mars to loose 1% of the mass of its atmosphere. Even if the rate of mass loss were 10 times higher than measured by MAVEN (it's known to increase during solar storms and in perihelium), it'd still take nearly 8 million years. Looks like if we can increase density and pressure of Martian atmosphere as GP suggested, we don't really need to worry about the lack of magnetospheric protection. [1] https://en.wikipedia.org/wiki/Atmosphere_of_Mars https://en.wikipedia.org/wiki/Atmosphere_of_Mars [2] https://www.nasa.gov/press-release/nasa-mission-reveals-speed-of-solar-wind-stripping-martian-atmosphere https://www.nasa.gov/press-release/nasa-mission-reveals-spee...

Ah yeah, forgot about that. And restarting the core dynamo seems pretty infeasible regardless or our technological capabilities.

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throwawayaway12 9y ago

I think it is still an open (and hotly debated) question on if planets need magnetospheres to retain an atmosphere.

toomuchtodo 9y ago
A magnetosphere is required to shield from charges particles and other harmful radiation.
- deleted 9y ago
  [deleted]
ethbro 9y ago
* also, retain an atmosphere "over long enough timescales" From the MAVEN research papers I've read, we're talking ~5,000 metric tons / yr of atmosphere being stripped. Which is a lot, but not an insurmountable lot.

YokoZar 9y ago

Mars has isolated pockets of "mini magnetospheres" that are suitable enough to block charged particles. http://www.space.dtu.dk/english/Research/Universe_and_Solar_System/magnetic_field http://www.space.dtu.dk/english/Research/Universe_and_Solar_...

maxk42 9y ago
I think he was assuming the subject was terraforming. Without a magnetosphere, the atmosphere will keep being blasted off into space continuously, and it'll be impossible to terraform.
- mkl 9y ago
  Continuously, but slowly, over very long time scales. Maintaining an atmosphere suitable for us is probably far easier than constructing it in the first place.

avz 9y ago

I don't think that's necessary. The loss of atmosphere by Mars may have been significant on the timescale of its five-billion-years history, but not on the timescale of a human settlement project. The mass of the Martian atmosphere is about 25 teratonnes [1]. According to the measurements by MAVEN, the rate of mass loss by Martian atmosphere due to solar wind is 100 g/s [2]. At this rate it would take 25e12 * 1000 * 1000 * 0.01 / 100 / 3600 / 24 / 365.25 = 79 million years for Mars to loose 1% of the mass of its atmosphere. Even if the rate of mass loss were 10 times higher than measured by MAVEN (it's known to increase during solar storms and in perihelium), it'd still take nearly 8 million years. Looks like if we can increase density and pressure of Martian atmosphere as GP suggested, we don't really need to worry about the lack of magnetospheric protection. [1] https://en.wikipedia.org/wiki/Atmosphere_of_Mars https://en.wikipedia.org/wiki/Atmosphere_of_Mars [2] https://www.nasa.gov/press-release/nasa-mission-reveals-speed-of-solar-wind-stripping-martian-atmosphere https://www.nasa.gov/press-release/nasa-mission-reveals-spee...