In a Lagrange point it's actually quite trivial to create a man made magnetic field to protect the planet. Dr Jim Green, director of planetary science at NASA w

In a Lagrange point it's actually quite trivial to create a man made magnetic field to protect the planet. Dr Jim Green, director of planetary science at NASA worked on it and fleshed out the details, it's viable and would actually restore a lot of the atmosphere stripped away constantly. As far as colonisation problems go the magnetic field is far down the list. There's a lot of work being done in this field. https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmosphere.html https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmo...