The planet Jupiter has a strong magnetic field which traps and holds very fast moving electrons. These electrons radiate radio waves producing the large extended features beyond the planet's disk seen in the VLA picture of Jupiter. The electrons and magnetic field outside of Jupiter's atmosphere form a region very similar to the Earth's Van Allen radiation belt. Optical emission from Jupiter arises only from the planet disk itself, because the relativistic particles are not energetic enough to emit in the optical spectrum. The gas in the atmosphere of the planet itself also produces radio emission.