Planetary magnetism refers to the magnetic fields generated by planets, which can influence their atmospheres and protect them from solar winds. For instance, Earth has a strong magnetic field that shields it from harmful cosmic radiation, making it conducive to life. Different planets exhibit varying degrees of magnetism. Jupiter, for example, has the strongest magnetic field among the planets in our solar system, while Mars has a weak and patchy magnetic field. Understanding these magnetic fields helps scientists learn about a planet's interior structure and its potential for habitability.