Io's atmosphere and ionosphere: New limits on surface pressure from plasma models
Abstract
We have studied charge particle impact as a mechanism for the production of Io's ionosphere. Pioneer 10 thermal plasma measurements and magnetospheric plasma models which explain the observed spatial distribution of neutral hydrogen and sodium atoms in the vicinity of Jupiter’s satellite Io imply electron fluxes of ∼1010 cm-2 sec-1. The fluxes and the temperature (∼100 eV) of this plasma suggest that electron impact ionizaion is the dominant process in forming the ionosphere of Io. It is found that the surface number density of the neutral species required to match the observed electron density profiles is ∼109 cm-3 or less. This value is two orders of magnitude lower than previous estimates.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- June 1976
- DOI:
- 10.1029/GL003i006p00293
- Bibcode:
- 1976GeoRL...3..293J
- Keywords:
-
- Astronomical Models;
- Atmospheric Pressure;
- Io;
- Ionospheric Electron Density;
- Jupiter Atmosphere;
- Planetary Ionospheres;
- Thermal Plasmas;
- Atmospheric Ionization;
- Earth Magnetosphere;
- Electron Density Profiles;
- Electron Impact;
- Pioneer 10 Space Probe;
- Planetary Atmospheres;
- Plasma Diagnostics;
- Particles and Fields-Ionosphere: Ion densities and temperatures;
- Particles and Fields-Ionosphere: General or miscellaneous;
- Planetology: Atmospheres of planets