A

David

Darling

plasmasphere

plasmasphere

The plasmasphere is a donut-shaped region of relatively cool (2,000 K), dense (tens to thousands of particles per cubic centimeter) plasma within Earth's magnetosphere that extends out to a distance of about 4 Earth radii (25,000 km) and is bounded by the inner Van Allen belt. The outer limit of the plasmasphere is called the plasmapause.