Significant variation from a 1/R² potential in the cumulative flux determined from the Giotto Comet Halley Dust Impact Experiment.

Abstract

The Giotto Comet Halley probe successfully traversed the inner coma of Comet Halley on March 14, 1986. The Dust Impact Detection System (DIDSY) aboard the Giotto spacecraft provided the information on the dust flux, mass spectrum, and cumulative mass distribution flux in the coma of Comet Halley. Analysis of discrete pulse height data of cometary particles for the mass range of particles between 4.0×10^-10g and 6.0×10^-6g registered by the Giotto DIDSY detectors 2, 3, and 4 has been completed (Pollock, 1987), and a cumulative flux has been determined for this size range of particles. Inside the cometopause, anomalous peaks have been identified as deviation from a 1/R² curve in both pre- and postencounter measurements. The relationship between these flux variations, plasma depletion zones, and the contact surface are discussed.