Ion temperature and flow profiles in Comet Halley's close environment
Abstract
The HIS instrument of the ion mass spectrometer on board the GIOTTO spacecraft identified the contact surface in 4800 km distance from the comet nucleus. This boundary is clearly seen by a drastic drop in the temperatures of different ion species from about 2000K outside to values as low as 300K inside. Also, inside the contact surface an outflow speed of >1 km s-1 was measured, in contrast to a value around zero right outside. The authors discuss how these numbers might be affected by a potential charge-up of the spacecraft. Outside the contact surface, the ion temperature rises gradually with increasing distance. Between 9000 and 10,000 km distance the ion density increases by a factor of 4. This "ion pile-up" is not yet explained uniquely. At 27,000 km distance there is again a rather abrupt jump to significantly higher temperatures, higher outflow speeds and lower densities.
- Publication:
-
ESLAB Symposium on the Exploration of Halley's Comet
- Pub Date:
- December 1986
- Bibcode:
- 1986ESASP.250a.225S
- Keywords:
-
- Comet Nuclei;
- Flow Distribution;
- Halley'S Comet;
- Ion Density (Concentration);
- Ion Distribution;
- Ion Temperature;
- Mass Spectrometers;
- Plasma Density;
- Plasma Temperature;
- Spacecraft Charging;
- Astrophysics;
- COMET NUCLEI;
- FLOW DISTRIBUTION;
- HALLEY'S COMET;
- ION DENSITY (CONCENTRATION);
- ION DISTRIBUTION;
- ION TEMPERATURE;
- MASS SPECTROMETERS;
- PLASMA DENSITY;
- PLASMA TEMPERATURE;
- SPACECRAFT CHARGING