EVIDENCE OF CURRENTS AND UNSTABLE PARTICLE DISTRIBUTIONS IN AN EXTENDED REGION AROUND THE LUNAR PLASMA WAKE

We report observations of electrostatic ion acoustic waves and Langmui r waves during a recent lunar encounter by the Wind spacecraft. These waves are observed when Wind is magnetically connected to the nominal wake and at distances greater than 8 lunar radii from the wake. When i nterpreted in the context of a simple time-of-flight model, these obse rvations imply the existence of a system of currents and disturbed par ticle distributions that extends far into solar wind.