The Magnetosphere of Jupiter
Perhaps the largest structure in the solar system is the magnetosphere of Jupiter. This is the region of space that is filled with Jupiter's magnetic field and is bounded by the interaction of that magnetic field with the solar wind, which is the Sun's outward flow of charged particles. The plasma of electrically charged particles that exists in the magnetosphere is flattened into a large disk more than 3 million miles (4.8 million kilometers) in diameter, is coupled to the magnetic field, and rotates around Jupiter. The Galilean satellites are located in the inner regions of the magnetosphere and are subjected to intense radiation bombardment.
The intense radiation field that surrounds Jupiter is fatal to humans. If astronauts were able to approach the planet as close as the Voyager 1 spacecraft did, they would receive a dose of 400,000 rads, or roughly 1,000 times the lethal dose for humans.
Even when nearest Earth, Jupiter is still almost 400 million miles away. However, because of its size, it may rival Venus in brilliance when near. Jupiter's four large moons may be seen through field glasses moving rapidly around Jupiter and changing their positions from night to night.
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