We are very jealous Dr. Novella! My fiance also works for Lockheed but on the J2X engine system, so we are at home watching the live broadcast. It is really awesome that you get the opportunity and that Elliot and Lockheed appreciate scientific skepticism enough to invite you all over there. One of our family friends is a program manager for Lockheed at KSC named Dennis Baird. If you happen to see him tell him Andrey Pavlov says hello.
The leading theory as to what happened is that Mars must have once also had a magnetic field, but this went away for some reason.
I think the idea is that Mars’ originally molten core cooled to the point that it no longer “spun” relative to the outer mantle; which is the “dynamo” that creates Earth’s magnetic field. Without the magnetic field that deflects the solar wind on Earth, that stream of particles “blew away” Mars’ atmosphere.
That also prevented tectonic movement of the upper crust, which, in turn, also explains Olympus Mons, the largest known volcano, because, unlike Earth volcanos, the “hot spot” that generated the volcano didn’t move relative to the surface. So, instead of creating multiple volcanos, as in the Hawaiian islands, Olympus Mons just got bigger and bigger.
I’m certainly curious about this sort of stuff. I remember watching a show that had a speculative effort to terraform Mars to the point that people could walk around wearing only an oxygen mask. I remember one phase involved building Martian factories with a carbon quota to raise the greenhouse effect and melt/sublimate the ice to contribute water vapor.
Given the issues of lower gravity and lack of volcanic activity, I wonder how sustainable a manmade atmosphere would be. The idea of Martian factories also strikes me as a bit implausible since our preferred methods of generating carbon dioxide depend on having oxygen for combustion, which seems like a luxury outside of Earth, so I’m curious where they’d extract it from and how. Of course, there’s also the cost of building those factories in the first place. It’s expensive enough to send mass into Earth orbit, so I don’t think it’d be easy to convince manufacturing companies to invest in Martian factories.
For Mars’ magnetic field, I think I recall hearing the same thing as John Pieret: The core cooled off and stopped spinning relative to the surface. Since we don’t live in the absurd fiction of The Core, I don’t think that’d be an easy issue to fix.