... 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. ...

... The ring current (e.g., Frank, 1967) consists of geomagnetically trapped 10 - 200 keV ions (mainly H + , He + , and O + ) and electrons that drift azimuthally around the Earth at radial distances of about 2-7 Re (Earth radii), overlapping the radiation belt region. ... This index can be used to monitor the development of geomagnetic storm (see also geomagnetic activity ), as the main signature (actually definition) of the storm main phase is the build-up of an enhanced ring current. ... Res., ...

... Phases of the Moon is at the top of the list of things that students seriously misunderstand. ... This phase is called "new moon" (like "no moon"). ... Note: although the Moon is closer to the Sun during new and crescent phases, it is still 400 times closer to Earth; i.e., the Sun is VERY far away in reality.) ... When the Moon reaches the position directly opposite the Sun, as viewed from Earth, the half viewed from Earth is fully illuminated (unless the student's head is causing a lunar eclipse). ...