PHOTO RELEASE NO.: STScI-PRC94-46         FOR RELEASE:   September 29, 1994

MONTH-LONG EVOLUTION OF THE D/G JUPITER IMPACT SITES FROM COMET
P/SHOEMAKER-LEVY 9
 
This series of snapshots, taken with NASA's Hubble Space
Telescope, shows evolution of the comet P/Shoemaker-Levy 9 impact
region called the D/G complex.  This feature was  produced by two
nuclei of comet P/Shoemaker-Levy 9 that collided with Jupiter on
17 and 18 July 1994, respectively, and was later modified again
by the impact of the S fragment on 21 July 1994.

Upper Left:  This first image was taken about 90 minutes after
the G impact on 18 July 1994.  Nearly all of the structure in
this image was created by the impact of fragment G, although a
small dark spot to the left was the remainder of small fragment D
that collided one day earlier.  The explosion of the nucleus in
Jupiter's atmosphere created the unique ring structure, which may
be analogous to a "sonic boom" on earth.  Though this structure
is best seen for the G impact, it is not unique.  Hubble reveals
similar rings around several other fresh impact sites.  They are
all clear evidence for coherent outward motion of this wave
phenomena.  

Upper right:  This second image, obtained on 23 July, shows that
the Jovian winds have swept the material into a striking
"curly-cue" structure.
 
Lower left, right:  The structure seen in earlier views has
disappeared rapidly in the images taken on 30 July and 24 August,
respectively.  Almost all of the changes between the images are
due to Jupiter's east-west winds that play a key role in the
dispersing of the dark material. 
 
Hubble Space Telescope's high resolution will allow astronomers
to continue to trace the impact debris as it is transported by
the Jovian winds.  This information promises to advance current
understanding of the physics of Jupiter's atmosphere.
 
These black and white images were taken in near-ultraviolet light
with the Wide Field Planetary Camera 2.  They have been processed
to correct for the curvature of Jupiter, so that the impact
region appears flat, as if the viewer were hovering directly
overhead.  Each image  is centered on -46 degrees latitude and 28
degrees.  The north-south extent in the image spans from -26 to
-66 deg. latitude and the east-west extent of the region spans
+/- 30 degrees on either side of 28 degrees longitude.
 
     credit: H. Hammel, MIT
                and NASA