system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How would terraforming Mars be possible?

I recall reading (somewhere) that the core of Mars is dead, and therefor incapable of producing the same type of magnetic field we have on earth.


How could life exist on the surface of Mars without the protection from damaging radiation provided by a functioning magnetic field?
gpt
Magnetic field protects the atmosphere, atmosphere protects from radiation. Mars used to have air, but it all got blown away by solar winds.

The first step would be creating an atmosphere. It would stabilize the temperature and we wouldn't need pressure suits, only oxygen tanks. To do this we would have to rise temperature with greenhouse effect by producing fluoride compounds (some of them are much more potent than CO2). After a while, the frozen CO2 would start to evaporate, increasing pressure and rising the temperature. There is enough of it, so that the pressure will be comparable with that atop mount Everest.

Alternatively, giant mirrors to make it hotter. 

Anyhow, once you have liquid water, you can start introducing algea and plants to make oxygen.