It would take about 3 weeks for material near the current sheet traveling at 400 km/s in the solar wind to reach the orbit of Jupiter, as depicted here. In reality the surface becomes increasingly distorted because of variations in the solar wind speed along the surface and other dynamic effects operating in the interplanetary medium.
The shape of the current sheet usually evolves slowly - over months - as the large-scale pattern of the Sun's field changes in response to the emergence and decay of solar active regions. Coronal mass ejections often disrupt the background pattern temporarily, but sometimes the changes are permanent.
During most of the solar cycle the current sheet is basically a tilted dipole with varying degrees of quadrupole distortion. Near solar maximum the dipole decays leaving a much more complicated structure. This picture shows the heliospheric current sheet as it might appear during the rising phase of the cycle, when the dipole and quadrupole components are balanced; at this point the neutral line at the base of the sheet resembles the seam on a baseball.
Prof. John M. Wilcox was one of the discoverers of the heliospheric current sheet and did much to develop our understanding of it during the 1960s and 1970s. He worked with NASA artist Werner Heil to create this picture. The shape for this solar rotation was based on Ken Schatten's Current Sheet Magnetic Model for the Solar Corona (Cosmic Electrodynamics, 2, 232-245, 1971). An early 3D rendering of the HCS appeared in a 1976 paper by L. Svalgaard and J.M. Wilcox in Nature (Vol 262, page 766).
Return to WSO Home Page