

NASA: Solar flares tear off tons of moon, Mars surface - coondoggie
http://www.networkworld.com/community/blog/nasa-solar-flares-tear-tons-moon-mars-surface

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Udo
This reminds me of a discussion I had with a physicist recently. He insisted
that the reason for Mars' atmosphere being gone was its low gravity. While it
seemed reasonable to me that this could partly be a factor, I (intuitively)
think the lack of a magnetosphere might play a bigger role in atmospheric
loss. Did someone here by chance do some calculations that could help settle
this argument?

(Note that the argument is NOT about smaller planet sizes leading to earlier
magnetosphere failures. It's strictly about what leads to a greater rate of
atmospheric loss: Mars' low gravity, or it's defective magnetosphere?)

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sanj
Can you explain why Mars's magnetic field is so weak? Or why it is
"defective"?

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boredguy8
Because it doesn't have a liquid magnetic core that rotates in a way that
creates a magnetic field. It's clear that at one point Mars did have a system
similar to Earth's, but it stopped and nobody knows why. The theory is that
one of the large collusions early in Mars' planetary formation caused surface
heat that disrupted the convection of the magnetic dynamo.
[http://www.universetoday.com/30538/was-mars-magnetic-
field-b...](http://www.universetoday.com/30538/was-mars-magnetic-field-
blasted-away/)

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wglb
So if a solar CME hits the moon when the moon is 'new', would some of that
truckload hit earth? Certainly this has happened in the past. Wonder if this
has been studied.

