heliospheric current sheet

The heliospheric current sheet, or interplanetary current sheet, is a surface separating regions of the heliosphere where the interplanetary magnetic field points toward and away from the Sun. A small electrical current with a current density of about 10−10 A/m2 flows within this surface, forming a current sheet confined to this surface. The shape of the current sheet results from the influence of the Sun's rotating magnetic field on the plasma in the interplanetary medium. The thickness of the current sheet is about near the orbit of the Earth. Characteristics Ballerina's skirt shape As the Sun rotates, its magnetic field twists into an Archimedean spiral, as it extends through the Solar System. This phenomenon is often called the Parker spiral, after Eugene Parker's work that predicted the structure of the interplanetary magnetic field. The spiral nature of the heliospheric magnetic field was noted earlier by Hannes Alfvén, based on the structure of comet tails.