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A.M. Cook (Connecticut College Dept. of Physics, Astronomy, and Geophysics.), P.A. Gerakines, Erik Saperstein (UAB Astro- and Solar-System Physics Program)
The icy planets and satellites of the Solar System are exposed to ultraviolet (UV) radiation from the Sun. This radiation drives photochemistry on the icy surfaces of planets like Pluto, Jupiter's moon Europa, and Saturn's moon Tethys. Mid-infrared laboratory spectroscopic studies of photolyzed planetary ice analogs indicate complex chemical reactions in the ice mixtures. The natures of these reactions give us clues about how organic chemistry may have evolved in the Solar System. Our experimental equipment has the ability to take near-IR (lambda=0.8-2.5 microns) and mid-IR (lambda= 2.5-25 microns) data almost simultaneously. This enables us to compare different spectral regions for each single sample, rather than measuring the near IR and mid IR separately, in different experiments, with different samples. Laboratory studies of photolyzed ices have been well documented in the mid IR spectral region and suggest interesting features in the near IR. However, in most studies, the features in the near IR are too small to study effectively, simply because the ices appropriate for photolysis studies (thickness less than 1 micron) are too thin to yield strong near-IR spectral features. Our research aims to amplify the features in this region of the spectrum by simultaneously depositing and photolyzing thick ices (10-100 microns) and to correlate these spectra with those of photolyzed ices in the mid IR. The data obtained from this research will be of great value to planetary science. Significant chemical and physical information about icy planets and satellites can be derived from their observation at near-IR wavelengths. Our near-IR data can be compared with observations of planets and satellites made with the Galileo NIMS, Cassini VIMS, or HST NICMOS spectrometers, or the upcoming NGST mission.
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Bulletin of the American Astronomical Society, 34, #3< br> © 2002. The American Astronomical Soceity.