Chemical Composition of Comets

1985年至1988年哈雷彗星的出现开启了探索早期太阳星云化学丰度的新纪元，乔托航天器采集了现场气体样本。此外，在大型地面望远镜上使用最先进的探测器产生了高质量的分光光度数据，非常适合于确定彗核挥发性成分的化学丰度。这笔赠款支持对彗核中挥发物丰度的研究。最终目标是将这些丰度与原始太阳星云中形成彗星的环境联系起来。方法是结合天文学家和理论家的努力，使用高质量的地面数据来约束彗星彗发的化学模型。该模型结合了重要的化学和光解彗发过程，将被用来推导出原子核中母物种的丰度。从这项研究中，研究人员希望对45亿年前发生在太阳星云最冷区域的化学过程得出重大限制。

The appearance of comet Halley in 1985-1988 opened a new era in probing chemical abundances in the early solar nebula with the collection of in situ gas samples by the GIOTTO spacecraft. Moreover, use of state-of-the-art detectors on large ground-based telescopes produced high quality spectrophotometric data ideally suited for determining chemical abundances of the volatile component of the comet nucleus. This grant supports the investigation of the abundances of volatiles in cometary nuclei. The ultimate goal is to relate these abundances to the environment for forming comets in the primitive solar nebula. The approach is to combine efforts of an observationalist and a theorist to constrain a chemical model of a comet coma using high quality ground-based data. The model which incorporates significant chemical and photolytic coma processes will be used to derive the abundances of the parent species in the nucleus. From this research the investigators hope to derive significant constraints on chemical processes which occurred in the coldest regions of the solar nebula 4.5 billion years ago.