8353(  2) - 12/18/98 16:43  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      8353
                                                       Version: 2
                                                       Check-in Date: 18-Dec-1998
                                                                      16:41:08

1.Proposal Title:
Constructing a 2-D Picture of Saturn's OH Cloud
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2. Proposal For  3. Cycle
AR               8
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4. Investigators
                                                                                     Contact?
    PI: John Richardson                   Massachusetts Institute of Technology
   CoI: Dr. Melissa McGrath               Space Telescope Science Institute             N
   CoI: Prof. Aharon Eviatar              Tel Aviv University                           N
   CoI: Dr. Vytenis Vasyliunas            Max Planck Institut fur Aeronomie             N

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5. Abstract

The discovery of OH changed our view of Saturn's magnetosphere from one where plasma
dominated the physics to one where neutrals are dominant. Four different sets of
Hubble/FOS observations map the OH emission; published results from two data sets
detected OH near the rings at 2 R_S and near the icy moons at 4.5 R_S. These are
line of sight observations which determine the OH column density; more information
is necessary to convert from column density to number density. We propose to combine
all four data sets to reconstruct the OH density distribution. The data encompass 14
different lines of sight at 4 different look angles. The full data set provides much
stronger constraints on both the radial and latitudinal distribution of OH than does
the published data. Building on past work, we will model the physics and chemistry
governing the neutral and plasma densities in Saturn's magnetosphere, and constrain
the neutral and plasma distributions observed by HST, Voyager 1, and Voyager 2 to be
consistent with our model results. The result of this work will be a 2-D picture of
the OH densities in the Saturn magnetosphere, knowledge which is crucial for
understanding neutral and plasma sources. Our results will also provide a set of
predictions and tools for the Cassini mission experiments, as well as the context
for linking data from the Voyager missions, HST observations and the Cassini
mission.
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  Data Distribution

  Paper Products:  NO
  Media:           ELECTRONIC
  Blocking Factor: 10
  Ship To:         PI_Address
  Ship Via:
  Email:
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                                                8353(  2) - 12/18/98 16:43  - [  2]

            Summary Form for Proposal  8353

  Item                         Used in this proposal
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  Proposal Category            AR
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