eldavojohn writes "When it comes to space exploration, there are things that are good for humans (water) and things that are bad for humans (radiation). In order for exploration of the moon to occur, its lack of a global magnetic shield to block solar radiation must be addressed. Luckily, scientists have discovered that there are highly magnetized areas of the moon's crust that could shield settlements." From the article: "Current evidence suggests that impact-basin ejecta materials [material blasted out by huge asteroid or comet impacts] are the most likely sources of many or all of the magnetic fields ... These ejecta contain microscopic metallic iron particles that are the carriers of the magnetization."