PDS: The Planetary Atmospheres NodeJovian System Data Analysis Program
Analysis ProgramCover Page/Proposal Summary
ROSS-99 NRA 99-OSS-01
Date Due: 5/5/99
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This proposal shall be used and disclosed for evaluation purposes only, and a copy of this Government notice shall be applied to any reproduction or abstract thereof. Any authorized restrictive notices that the submitter places on this proposal shall also be strictly complied with. Disclosure of this proposal for any reason outside the Government evaluation purposes shall be made only to the extent authorized by the Government. |
| Proposal Type: New Proposal |
| Proposal Category: Fields and Particles |
| Major Equipment Proposal? No |
| Do you intend to submit an Education/Public Outreach (E/PO) proposal? No |
| Proposal Title: |
| Analysis of GEM plasma data: The structure of the Io plasma torus and a search for an Europa plasma torus |
| Abbreviated Proposal Title: |
| The Io and Europa plasma torii |
| Principal Investigator: |
| Dr. Frank
Crary LASP University of Colorado Campus Box 392 Boulder, CO 80309-0392 Phone: 303-492-0344 Fax: 303-492-0642 E-mail: fcrary@dosxx.colorado.edu |
| Signature | Date |
| _____________________________________ | ____________ |
| Co-Investigators and Collaborators: | |||
| Type | Name | Affiliation | |
| Sci Co-I | Dr. Fran Bagenal | LASP | bagenal@dosxx.c olorado.edu |
Proposal Summary:
Galileo's particles and field instruments have collected a wealth of data on Jupiter's magnetosphere, including the Io plasma torus and the region near Europa's orbit. An important aspect of these data are measurements of the background plasma conditions. The background density, temperature and composition of the plasma are central to understanding magnetospheric processes. The large scale structure provide information on the sources and transport of plasma, as well as atmospheric loss/surface sputtering from the satellites of Jupiter. The torus has a complex but poorly understood structure in radial distance, longitude and local time. A comprehensive understanding of the Io torus requires in situ measurements covering a wide range of longitudes and local times. Galileo is in the process of making these measurements. Protons are present in the Io torus, may play an important role in the torus energy balance and dynamics, and are the dominant ion at higher latitudes. Despite this, very little is known about their density or distribution. These ions may come from Io (although hydrogen-bearing chemicals have never been detected on the surface of Io), Jupiter's atmosphere, or sputtered off the surface of the icy satellites. Galileo has also made extensive in situ observations near the orbit of Europa. Voyager ultraviolet spectra and Galileo J0 PLS measurements both show increasing oxygen abundance with distance from Jupiter, suggesting that Europa is a source of water group ions. Water sputtered from the icy surface of Europa could produce a torus of water group ions. We propose to analyze the PLS data and PWS measurements of electron density. We will use the results to help resolve these questions. We will: (a) determine the variability of the plasma parameters as a function of longitude, local time and radial distance (b) identify and quantify the source(s) of protons by determining their density and distribution (c) search for a Europa plasma torus.
