This drawing shows the difference between a dipole and a magnetosphere. Click on image for full size version (55K GIF) Image from the AGU Educator's Slide set. Image copyright 1997 by the American Geophysical Union. Further electronic distribution is not allowed.

A planetary magnetosphere is different from an ordinary dipole. The force of the solar wind, coming from the sun stretches the dipole and creates a nose region in the front of the magnetosphere (facing the sun), and a tail region in the back called a magnetotail.

If it weren't for the solar wind, the field lines of the planetary magnetic field would extend into infinity. But because the solar wind and IMF press upon a planet's magnetic field, and enclose it, the magnetic field is contained within a "cavity" called the magnetosphere. This magnetosphere naturally has a boundary and that boundary is called the magnetopause. The magnetopause can be considered to be the end of a planet's region of influence.

This drawing shows the difference between a dipole and a magnetosphere. Click on image for full size version (55K GIF) Image from the AGU Educator's Slide set. Image copyright 1997 by the American Geophysical Union. Further electronic distribution is not allowed.

A planetary magnetosphere is different from an ordinary dipole. The force of the solar wind, coming from the sun stretches the dipole and creates a nose region in the front of the magnetosphere (facing the sun), and a tail region in the back called a magnetotail.

If it weren't for the solar wind, a planet's magnetic field would extend forever. But because the solar wind presses upon a planet's magnetic field, and encloses it, the magnetic field is forced to stay within a "cavity" called the magnetosphere.

This magnetosphere naturally has a boundary and that boundary is called the magnetopause.

This drawing shows the difference between a dipole and a magnetosphere. Click on image for full size version (55K GIF) Image from the AGU Educator's Slide set. Image copyright 1997 by the American Geophysical Union. Further electronic distribution is not allowed.

A planetary magnetosphere is different from an ordinary dipole. The force of the solar wind, coming from the sun stretches the dipole and creates a nose region in the front of the magnetosphere (facing the sun), and a tail region in the back called a magnetotail.

If it weren't for the solar wind, a planet's magnetic field would extend forever. But because the solar wind presses upon a planet's magnetic field, and encloses it, the magnetic field is forced to stay within a "cavity" called the magnetosphere.

This magnetosphere naturally has an edge and that edge is called the magnetopause.