Observation by Pioneer 7 of He + in the distant coma of Halley's comet
Abstract
During the approach of Pioneer 7 to a distance of 12.1 × 10 6 km from the nucleus of Comet P/Halley on March 20, 1986, features were observed in plasma analyzer data that we interpret as He + produced by charge exchange of solar wind He ++ with neutral cometary material. The maximum flux of the He + was observed several hours after the closest approach of the spacecraft to the nucleus, and is unexpectedly large. Remarkable large discontinuous flux changes were also observed.
- Publication:
-
Icarus
- Pub Date:
- July 1987
- DOI:
- 10.1016/0019-1035(87)90172-2
- Bibcode:
- 1987Icar...71..192M
- Keywords:
-
- Halley'S Comet;
- Helium Ions;
- Plasma Diagnostics;
- Satellite Observation;
- Solar Planetary Interactions;
- Comet Nuclei;
- Particle Flux Density;
- Pioneer 7 Space Probe;
- Solar Wind;
- Time Dependence;
- COMETS;
- HALLEY;
- SPACECRAFT OBSERVATIONS;
- PIONEER 7 MISSION;
- SOLAR WIND;
- HELIUM;
- COMAE;
- SOURCE;
- FORMATION;
- INTERACTION;
- PLASMA;
- SPECTRA;
- IONS;
- DENSITY;
- COMPARISONS;
- DISTANCE;
- COMET NUCLEI;
- PLASMA ANALYZER INSTRUMENT