PDS_VERSION_ID                  = PDS3
RECORD_TYPE                     = STREAM

DATA_SET_ID                     = "HST-S-WFPC2-3-RPX-V1.0"

OBJECT                          = TEXT
  PUBLICATION_DATE              = 1998-07-17
  NOTE                          = "Abstract to HST proposal #5782, as
downloaded from http://presto.stsci.edu/public/propinfo.html in July
1997."
END_OBJECT                      = TEXT
END

                   SATURN RING-PLANE CROSSING, MAY 1995
                            HST Proposal 5782

Title:                 SATURN RING-PLANE CROSSING, MAY 1995
PI:                    AMANDA (LOWELL OBS.)
Category:              SOLAR SYSTEM
Cycle:                 5
Continuation ID:
Status:                completed
                                 Abstract
In 1995-1996, the Earth and the Sun will pass through Saturn's ring plane.
The Earth will pass through 3 times (22 May 1995, 10 August 1995, 11 Feb
1996), and the Sun will pass through once (19 November 1995). All but the
11 Feb 1996 event will be visible from HST. During the crossings of the
Earth through Saturn's ring plane, the rings will become very thin and
dark. By monitoring the brightness of the rings as they become very thin,
we will be able to determine the time of ring-plane crossing and the
residual brightness of the rings at this time. The time of the ring- plane
crossing will place additional constraints on the precession rate of
Saturn's pole. The recent occultations by Saturn's rings have produced a
measurement of this value, but it is not known very well (French et al.,
1993; Bosh, 1994; Elliot et al., 1993). A measure of the brightness of the
rings in their edge-on configuration, combined with photometric properties
of the rings derived from early calibration observations will allow us to
determine the thickness of the rings.