July 19, 1994

An observing team from the University of Wyoming , the
University of Rochester, and the University of Minnesota
is obtaining infrared images of the recent comet impacts
on Jupiter.  The observations are being made with the
Wyoming Infrared Observatory 2.3-meter telescope near Laramie,
using an infrared camera developed at Rochester.

The accompanying image of Jupiter, obtained on the evening of Sunday
July 17, shows three bright spots near the lower left.  These are
the impact sites of (from left to right) fragments C, A, and E.  The
other features visible are the bright polar and equatorial regions,
and also the Great Red Spot, located below the equator and somewhat to
the right.  At this relatively short infrared wavelength (2.2 micrometers)
the planet it mostly dark because the methane in the Jupiter atmosphere
absorbs any sunlight which passes through a significant depth of that
atmosphere.  Bright regions usually correspond to high altitude clouds
which reflect the sunlight before it can penetrate the deeper atmosphere
and be absorbed.  The bright nature of the impact spots therefore
indicates the presence of high altitude haze or clouds -- material carried
up from the lower atmosphere by the fireball and plume from the comet
impact.  More detailed measurements at a variety of wavelengths should
reveal the chemical composition of the haze material.  The observing team
will be continuing their work throughout the comet impact period and expect
to obtain images of the plumes from the other comet fragments which will
be striking Jupiter later this week.

Contact: Robert R. Howell
         Department of Physics and Astronomy
         University of Wyoming
         Laramie, WY  82070
         307-766-6150