Magnetosheath phenomena at lunar distances
Sanders, Gary (Gary D.)
Freeman, John W.
Master of Science
Simultaneous data returned by the Apollo Suprathermal Ion Detector Experiments are combined to yield information on the properties of plasmas in the magnetosheath at lunar orbit. Recent analysis of magnetosheath data has shown that the magnetosheath at lunar distances consists of two proton populations having different temperatures. There is evidence that the colder component (kT~1 ev) is unshocked solar wind. The hotter component (kT~1 ev) is characteristic of shocked solar wind. This two temperature structure is observed across the entire magnetosheath at lunar orbit. In addition an interface between the magnetosheath and the plasma sheet is identified. This layer is identified by a systematic change in the magnetosheath flow properties in the vicinity of the magnetopause. The flow is observed to turn inward toward the plasma sheet and become thermalized indicating that the magnetosheath particles can gain access to the plasma sheet at lunar distances. This layer, which we term the injection layer, is believed to be the extension of the entry layer observed on the dayside to lunar orbit.