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

土卫六是土星上最大的卫星。土卫六的表面将使用一种高空间分辨率和光谱分辨率成像的强大组合，在迄今从地球上从未探索过的波长区域进行探测。土卫六大气中的甲烷吸收导致大气中甲烷分子吸收较低的波长在~0.83微米到2微米之间的“窗口”，从而允许探测土卫六的表面。之前对土卫六表面的空间分辨率成像显示了离散的明暗区域，这意味着土卫六并不像之前所说的那样被全球碳氢化合物海洋覆盖。声光可调谐滤光片相机具有比窄带滤光片更高的光谱分辨率，可以调谐到0.5-1.05微米的任何波长，在0.94微米的大气窗口内观测到了土卫六的图像。这些观测是在1999年秋天从威尔逊山天文台的100英寸望远镜上进行的，该望远镜配备了一个自适应光学系统，允许对土卫六的圆盘进行高空间分辨率成像。1999年秋季的观测覆盖了土卫六的一个半球，第二组观测计划于2000年秋季进行，届时将覆盖另一个半球。因此，泰坦表面的完整地图将是可能的。这两个数据集将以相同的方式进行简化和建模，以获得有关土卫六表面在0.9微米波长窗口中的反射率的信息。与其他研究人员在较长波长区域近红外大气窗口的研究结果相比较，将揭示土卫六亮区和暗区的光谱相关性。这将提供对土卫六表面组成的新见解，这将是一个及时的结果，预计卡西尼/惠更斯卫星探测器将于2004年前往土卫六执行任务。研究生和本科生参与所有级别的研究将加强新墨西哥州斯塔尔大学的科学教育，新墨西哥州是一所少数民族大学。该项目由天文学司和数学和物理科学局多学科活动办公室资助。*

AST -0074923ChanoverTitan 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.***