... a) As source material for the high-school or college curriculum, especially in physics. astronomy and their history. (b) As a source of supplemental projects by high school students or by undergraduates. (c) As material for independent studies, In particular by motivated students who seek to know more about space . ... Those wishing to look up specific topics are advised to use the index file, accessible from the end of any "Exploration" file. ... files not listed and at other resource material. ...

... Field Lines . ... Charged particles--ions and electrons--can be trapped by the Earth's magnetic field. ... A fast rotation (or "gyration") around magnetic field lines, typically thousands of times each second. ... A slow drift around the magnetic axis of the Earth, from the current field line to its neighbor, staying roughly at the same distance from the exis. ... Electrons and ions, of the energies commonly encountered in the magnetosphere, tend to circle around magnetic field lines. ...