This Textbook Describes Earth's Plasma Environment From Single Particle Motion In Electromagnetic Fields, With Applications To Earth's Magnetosphere, Up To Plasma Wave Generation And Wave-particle Interaction. The Origin And Effects Of Collisions And Conductivities Are Discussed In Detail, As Is The Formation Of The Ionosphere, The Origin Of Magnetospheric Convection And Magnetospheric Dynamics In Solar Wind-magnetosphere Coupling, The Evolution Of Magnetospheric Storms, Auroral Substorms, And Auroral Phenomena Of Various Kinds.the Second Half Of The Book Presents The Theoretical Foundation Of Space Plasma Physics, From Kinetic Theory Of Plasma Through The Formation Of Moment Equations And Derivation Of Magnetohydrodynamic Theory Of Plasmas. The Validity Of This Theory Is Elucidated, And Two-fluid Theory Is Presented In More Detail.