名詞 magnetosphere:

1. the magnetic field of a planet; the volume around the planet in which charged particles are subject more to the planet's magnetic field than to the solar magnetic field

mag.ne.to.sphere

n.（名詞）
An asymmetrical region surrounding the earth, extending from about one hundred to several thousand kilometers above the surface, in which charged particles are trapped and their behavior is dominated by the earth`s magnetic field.
磁層：地球周圍的一個(gè)不對(duì)稱區(qū)域，從地球表面向空中延伸大約一百公里到數(shù)千公里，在磁層里電荷的粒子活動(dòng)受到限制，它們的運(yùn)動(dòng)受地球的磁場(chǎng)支配