Many of the terraforming plans include creating a magnetic field, e.g., a fully artificial one situated at L1. https://en.wikipedia.org/wiki/Terraforming_of_Ma

Many of the terraforming plans include creating a magnetic field, e.g., a fully artificial one situated at L1. https://en.wikipedia.org/wiki/Terraforming_of_Mars#Magnetic_shield_on_L1_orbit https://en.wikipedia.org/wiki/Terraforming_of_Mars#Magnetic_...