Most of these particles, which are ionized and swept up by the field, come from the volcanic gases spewing from Jupiter’s moon Io.
About 5.3 million kilometers (3.3 million miles) wide on average, the magnetosphere is 150 times wider than Jupiter itself and almost 15 times wider than the Sun.
Jupiter’s magnetic field funnels some of the charged particles in the magnetosphere toward the poles, where they interact with the atmosphere to produce brilliant auroras – northern and southern lights. Juno’s orbits around Jupiter’s poles are designed to allow the spacecraft to measure the gravitational and magnetic fields, and the amount of water in the atmosphere. But they will also enable Juno to venture into unexplored regions of the magnetosphere and observe the auroras in unprecedented detail, learning more about the processes that control them.
In particular, Juno’s instruments will count the number of charged particles that trigger auroras. And the plasma- and radio-wave instruments will take ultraviolet and infrared images to understand how the magnetic field accelerates these particles.
The magnetosphere also enables us to measure how fast Jupiter spins.
Observing Jupiter’s clouds doesn’t help because they rotate at varying speeds and are not directly connected to the planet’s interior. But the magnetosphere rotates along with Jupiter because it’s driven by the magnetic field, which is generated deep inside the planet.
Jupiter’s magnetosphere is 150 times wider than the planet itself, and its tail stretches all the way to Saturn’s orbit.
Co-Investigators Fran Bagenal and Jeremy Bloxham describe the source of Jupiter’s magnetic personality.
The spacecraft’s special orbit provides access to an unexplored region of Jupiter.
Jupiter is surrounded by a belt of radiation stronger than any in the solar system, except for the Sun.
Plasma is an electrically charged gas.
Brilliant displays of light illuminate a ring around Jupiter’s poles when charged particles slam into its atmosphere.