Vincent Walker wrote:
lal_truckee wrote:


Vincent Walker wrote:

The theory is that the reversing of polarity was the
reason that Mars eventually lost its atmosphere.

What theory is that, pray tell?


I saw this on Nova on PBS. Basically besides gravity the atmosphere is believed to be held in
place by magnetic forces. As the molten cores of the terran planets cool over time their
magnetic fields reverse and weaken. Mars, by the combination of its smaller size and
position in the solar system - theoretically of course - eventually lost its ability to hold an
atmosphere in place.

Hmmm. It's my belief that Mars has an atmosphere. It's
not as dense as Earth's, and it's high in CO2, but it's
there.

Could you 'splain to me how magnetism can possibly hold
an atmosphere in place?