Final answer:
Jupiter and Saturn generate their intense magnetic fields through electric currents in their rapidly spinning interiors. Charged particles spiral around in the magnetic field, causing them to be accelerated to high energies. In the case of Jupiter, its moon Io plays a role in accelerating charged particles into its magnetosphere.
Step-by-step explanation:
Both Jupiter and Saturn generate their intense magnetic fields through the interaction of electric currents in their rapidly spinning interiors. These electric currents create strong magnetic fields that extend into space, forming their magnetospheres. Inside the magnetospheres, charged particles spiral around in the magnetic field, leading to their accelerated high energies.
For example, in Jupiter's case, charged particles are accelerated by volcanic eruptions from its moon Io, which blast them into space and into Jupiter's magnetosphere.