Oh, I don't care about the surface viability. An asteroid capable of altering the core would probably liquefy a significant portion of the planet though which is also not desirable.

The goal of the thought is to give the planet a magnetosphere closer to that of earth, anywhere between would be a success. The general idea is to get the core somewhat hotter and moving much more, which probably also means it needs a more beefy moon than it has to maintain the change for any significant amount of time.

idk it's just an idea I like to kick around sometimes.