Interaction of the Magnetized Solar Wind with the Moon

The experimental results obtained from the Explorer 35 spacecraft indicate that a detached bow shock wave does not exist in the vicinity of the moon. Thus, the flow conditions near the moon do not resemble those near the magnetosphere of the earth. The solar-wind flow around the moon is treated theoretically as a free-molecule flow of guiding-center plasma. Analytical results are obtained to describe the ion flow in the vicinity of the moon. The disturbed region forms a long wake in the downstream of the moon. The thickness of the wake, measured perpendicular to the plane of the solar-wind velocity and the interplanetary magnetic field, is constant at one lunar diameter. On the other hand, the width of the wake, measured parallel to that plane, increases with distance from the moon.