Beginning at 1994 Jul 17 7:15 UT, the NASA/Infrared Telescope Facility
observed the development of a bright spot on Jupiter associated with
the impact of fragment C.  The NSFCAM near-infrared camera took
0.9-sec integrations every 3.6 seconds at a wavelength of 2.248 +/-
0.011 microns.  Starting at 6:51 UT, the camera recorded Io and
Europa, searching for a flash; no flash was obvious but the data are
yet to be photometrically reduced.  At 7:15 the telescope moved to
Jupiter, and detected both the remnant of the A impact, with a surface
brightness similar to that of the south polar hood at this wavelength,
and a dim spot from fragment C.  By 7:18, site C was considerably
brighter than site A, but by 7:28 site C had faded to about site A's
brightness, and continued to fade until about 7:40, when it was
considerably fainter.

The accompanying image was taken at 8:18 UT at a wavelength of 3.8
microns.  Jupiter's south pole is in the lower left corner.  The Great
Red Spot, white in this image, is the large oval on Jupiter's east
limb.  The familiar atmospheric bands are also visible.  On the left
edge of the image are two spots.  The bright spot on the limb is site
C; the dimmer spot closer to the center of the planet is site A, from
an impact about 11 hours earlier.  This wavelength is sensitive to
relatively high altitudes, and site C is still bright at this
wavelength.

NASA/IRTF Comet Collision Science Team
