This image shows the torus of material around the moon Io.
Click on image for full size
Catalina Observatory.

The Io Torus

A satellite which has an atmosphere, such as Jupiter's moon Io, and which also is inside a magnetosphere (unlike the Earth's moon), will leave a cloud of particles behind as it orbits the planet. This cloud of particles is called a torus.

Eventually all the particles in the cloud will be turned to ions. The presence of ions causes a number of noticable effects in a magnetosphere:

  • slows down the magnetic field as it goes around the moon
  • may drive currents

Last modified September 22, 2003 by Randy Russell.

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