POWRE: Probing Titan's Surface With Acousto-Optic Imaging

New Mexico State University, Las Cruces NM

Investigators

Abstract

AST -0074923 Chanover Titan is the largest moon of the planet Saturn. Titan's surface will be explored using a. powerful combination of high spatial and spectral resolution imaging in wavelength region heretofore unexplored from the Earth. The methane absorption in Titan's atmosphere results in atmospheric "windows" between ~ 0.83 and 2 microns wavelength where the absorption of the methane molecule is low, allowing the surface of Titan to be probed. Previous spatially resolved imaging of Titan's surface revealed discrete bright and dark regions, which imply that Titan is not covered with a global hydrocarbon ocean as had been previously suggested. An acousto-optic tunable filter camera, which has higher spec-tral resolution than narrow-band filters and the ability to tune to any wavelength between 0.5 - 1.05 microns, was used to make observations of the image of Titan in the 0.94 micron atmospheric window. These observations were made in the fall of 1999 from the Mount Wilson Observatory 100-inch telescope, which is equipped with an adaptive optics system that allowed for high spatial resolution imaging of Titan's disk. The fall 1999 observations covered one hemisphere of Titan, and a second set 0f observations is planned for the Fall of 2000 that will cover the opposite hemisphere. Thus a complete mapping of Titan's surface will be possible. Both data sets will be reduced and modeled in the same manner to yield information about the reflectivity, of' Titan's surface in the 0.9 micron wavelength window. When compared with results of other investigators looking in longer wavelength regions near-infrared atmospheric windows, the spectral dependence of Titan's bright and dark regions will be revealed. This will provide new insight into the composition of Titan's surface, which will be a. timely result in anticipation of the Cassini/Huygens satellite probe mission to Titan in 2004. The participation of a graduate and undergraduate student in all levels of the research will enhance science education at New Mexico Stale University, a minority univer-sity. This project is funded by the Division of Astronomical Sciences and the Office of Multidisciplinary Activities in the Mathematical and Physical Sciences Directorate. ***