The Spacecraft
Observing Magnetic Fields

Jupiter's huge, intense magnetic field behaves as though there were a giant bar magnet inside the planet. The magnetic field acts as a deflector shield against the stream of particles in the solar wind coming from our Sun. Instead of striking Jupiter, some of these charged particles get caught inside the magnetosphere, where they are accelerated to enormous speeds and zip along the planet's magnetic field lines.

Night Side Jovian Aurora

Galileo measures Jupiter's magnetic field while passing through it. To avoid picking up interference, certain instruments are held away from the spacecraft. The Magnetometer measures the strength and direction of the field. The Energetic Particle Detector and the Plasma Instrument determine the number, energy, and direction of the particles inside the magnetosphere and in the solar wind. A Plasma Wave detector senses waves in the streams of particles.

	The Magnetometer senses magnetic fields in the spacecraft's immediate environment.

Galileo's camera records a bright aurora, as fast-moving particles from the Sun follow magnetic field lines into Jupiter's atmosphere. The beautiful glow results as the charged particles strike the upper atmosphere. The aurora also glows in ultraviolet light, which is measured by Galileo's Ultraviolet Spectrometer and Extreme Ultraviolet Spectrometer.

Next: Observing Interiors