plasma sheet

plasma sheet

[′plaz·mə ‚shēt] (geophysics) A region of relatively hot plasma outside the plasmasphere, which reaches, during quiet times, from an altitude of about 30,000 miles (50,000 kilometers) to at least past the moon's orbit in a long tail extending away from the sun; composed of particles with typical thermal energies of 2 to 4 kiloelectronvolts.