Online Praxis 1996 April/OP4_96.ISO/surfen/astro/solar/satrpc8.txt

Text File | 1996-02-16 | 2KB | 34 lines

FOR RELEASE: 3:00 p.m. (EDT) August 11, 1995

PHOTO RELEASE NO.: STScI-PRC95-31


                HUBBLE AGAIN VIEWS SATURN'S RINGS EDGE-ON

Saturn's magnificent ring system is seen tilted edge-on -- for the
second time this year -- in this NASA Hubble Space Telescope picture
taken on August 10, 1995, when the planet was 895 million miles (1,440
million kilometers) away. Hubble snapped the image as Earth sped back
across Saturn's ring plane to the sunlit side of the rings.  Last May
22, Earth dipped below the ring plane, giving observers a brief look at
the backlit side of the rings.  Ring-plane crossing events occur
approximately every 15 years.  Earthbound observers won't have as good
a view until the year 2038. Several of Saturn's icy moons are visible
as tiny starlike objects in or near the ring plane. They are from left
to right, Enceladus, Tethys, Dione and Mimas.  "The Hubble data shows
numerous faint satellites close to the bright rings, but it will take a
couple of months to precisely identify them," according to Steve Larson
(University of Arizona). During the May ring plane crossing, Hubble
detected two, and possibly four, new moons orbiting Saturn.  These new
observations also provide a better view of the faint E ring, "to help
determine the size of particles and whether they will pose a collision
hazard to the Cassini spacecraft," said Larson.  The picture was taken
with Hubble's Wide Field Planetary Camera 2 in wide field mode.  This
image is a composite view, where a long exposure of the faint rings has
been combined with a shorter exposure of Saturn's disk to bring out
more detail.  When viewed edge-on, the rings are so dim they almost
disappear because they are very thin -- probably less than a mile
thick.

Credit: Phil Nicholson (Cornell University) and NASA