Mars and Venus Nightglows: Inferences from Minor Species Emissions

AST 0307922 slangerdr。Tom Slanger和他在SRI国际的同事将分别使用哈勃太空望远镜和位于阿帕奇角天文台的ARC 3.5米望远镜，对火星和金星大气的可见光和近红外夜光进行观测。火星夜光光谱以前从未被行星探测器或近地望远镜记录过。斯兰格博士预测，OH自由基的迈尼尔波段辐射将是火星夜光的显著特征，这些辐射将提供有关火星中层大气中氢原子和臭氧分子丰度的重要信息，并间接提供有关大气中水的命运的信息。还将进行分子和原子氧发射的观测，为我们几乎没有直接信息的氧原子剖面模型提供重要的约束。这个小组对金星可见夜光光谱的开创性望远镜观测产生了重大影响。氧绿线发射的发现挑战了目前对氧能量转移动力学的解释。它的强度是高度可变的（1975年没有，1999年有，2001年又没有），这激发了一个正在进行的观测项目，以阐明变率的起源，以及对理解昼夜、水平和垂直运输的含义。该项目将与新墨西哥州立大学天文系密切合作进行。近年来利用天文天空光谱开展的广泛工作将因该项目所需的直接合作和交流而大大加强。在过去的十年中，SRI分子物理实验室在NSF本科生研究经验（REU）项目中接待了近100名本科生。这种互动将继续。* * *

AST 0307922SlangerDr. Tom Slanger and colleagues at SRI International will perform observations of the visible and near-infrared nightglow emissions from the atmospheres of Mars and Venus, using the Hubble space Telescope and the ARC 3.5-m telescope at the Apache Point Observatory, respectively. The Mars nightglow spectrum has never been recorded previously, either by planetary probes or by near-Earth telescope observations. Dr. Slanger predicts that Meinel band emissions from the OH radical will be prominent features in the Mars nightglow and that these emissions will provide essential information about the abundances of hydrogen atoms and ozone molecules in the Mars middle atmosphere, and indirectly provide information about the fate of atmospheric water. Observations of molecular and atomic oxygen emissions will also be performed, providing important constraints on models of oxygen atom profiles, about which we have little direct information. This group's pioneering telescope observations of the visible nightglow spectrum of Venus are having a significant impact. The discovery of oxygen green-line emission has challenged current interpretations of oxygen energy-transfer kinetics. That its intensity is highly variable (absent in 1975, present in 1999, and absent again in 2001) motivates an on-going program of observations to elucidate the origins of variability and the implications for understanding dayside-to-nightside, horizontal, and vertical transport. The project will be conducted in close collaboration with the Astronomy Department at New Mexico State University. The extensive work carried out in recent years using astronomical sky spectra will be substantially enhanced by the direct collaboration and communication that will be required on this project. Over the last decade, the SRI Molecular Physics Laboratory has acted as host to almost 100 undergraduates in the NSF Research Experiences for Undergraduates (REU) program. This interaction will continue. ***