Jupiter's Magnetosphere!!! (Although, I'm up to being schooled on this. This was recently learned on my part.)
Jupiter's magnetosphere is very special. It is the biggest thing in the entire solar system. Not only is it big enough to hold all of Jupiter's moons, but the sun itself could fit inside. It goes all the way to Saturn. If it could be seen at night, it would be as big in the sky as the full moon or up to five times as big.
Jupiter has a wind-sock shaped cloud which goes around inside the magnetosphere. Jupiter's magnetosphere is so powerful it also makes radio signals and other waves, called whistler waves, chorus and hiss. In fact, you can tune your radio to an empty station, late at night in the desert, and you would be able to hear the sucker. You would hear a kind of roar or weird science fiction sounding noises. People have been seriously creeped out by it's noise. The magnetic field is so intense and wide, that it influences Earths magnetic field, adding billions of watts of electrical energy to it. Essentially, Jupiter is on big nuclear power plant in the sky.
The magnetic field is generated by eddy currents in Jupiter's metallic hydrogen core. Magnetic fields are pretty interesting and intense things. If it weren't for Earth's big magnetic field, the sun's solar wind probably would have blasted our atmosphere off long ago, evaporating all the water, causing the atmosphere to become very dense and heated, sending the greenhouse effect out of control. In a couple million years, we'd be looking like Venus- a 900 degrees hell pit.
Jupiter's magnetosphere is a dangerous place. If you or I were to venture into any part of that puppy, then we'd be dead in short order. If astronauts ever try to go there, they will have to have some serious lead protected suits, not to mention a lead-lined spaceship. That would mean that we would have to build the space ship to Jupiter in space, because it would be too heavy to blast off! Also, parts of Jupiter's magnetosphere hold the hottest parts of our Solar system. Even hotter than the sun. Jupiter's magnetosphere reaches all the way to Saturn. Huge. If it were say, where Mars is in the solar system line up, we might be living in a very different world. Or not living.