heliosphere[hē′lē ō sfir′]
the region around the sun, extending beyond Pluto, characterized by the presence of the solar magnetic field and the solar wind
The roughly spherical volume of space, centered on the sun and extending into the Kuiper belt, that is composed of particles emitted from the sun and forms a bubble that displaces the interstellar medium.
OriginSee also: héliosphère
helio- + -sphere