On determination of the location of the Earth's magnetosphere boundary and collisionless shock wave

Abstract

Interpretation of the data received from artificial earth satellites on the particle density and magnetic field intensity in the region of 8–20 earth radii toward the sun has been the subject of some discussion. It is generally conceded that there are two relatively permanent bondaries in this region: the earth's magnetosphere and the collisionless shock wave (see Figure 1 ). Satellite results on the location of these surfaces are in general agreement with a continuum theory which assumes a ratio of specific heats γ of 2 (see, e.g., Figures 26 and 28 of Ness et al. [1964]). Although the data scatter about the smooth theoretical curves, the presence, gross nature, and form of the magnetosphere and collisionless shock wave are confirmed.