Collaborative Proposal: Comets and the History of Volatile Matter During Planetary System Formation

彗星是太阳系早期的天体，与太阳系创建时基本没有变化。彗星的轨道追踪到它们在外太阳系中形成的位置。彗星释放出的分子的组成可以通过观察它们的光谱信号来测量。将这些成分与彗星轨道结合起来，科学家们就可以了解到早期太阳系不同位置存在哪些物质。研究人员将测量彗星光谱中许多分子的数量，包括H2O、HDO、CH4、C2H2、C2H6、H2S、SO2、OCS、CO、H2CO、CH3OH、HCOOH、HCN、HNC、CH3CN、HC3N、NH2 CHO和NH3。他们将使用地面天文台，如NASA红外望远镜设施、W.M.Keck天文台和阿塔卡马大毫米/亚毫米阵列。2017-2019年为研究木星家族彗星提供了一个极好的机会--木星家族彗星的轨道较小，对其组成知之甚少。这项研究通过提高我们对作为太阳系基石的材料的了解，服务于国家利益。在沃森-金天文馆、陶森大学和密苏里大学的展览上，圣路易斯的新天文馆将展示这项研究。来自圣路易斯和巴尔的摩的学生，包括许多少数族裔学生，将有机会看到他们。首席研究人员将使用彗星的高分辨率分子光谱来测量从彗星核释放的挥发物的组成，并测试关于太阳系早期形成的理论。虽然观测到的彗星的轨道将它们与它们的动力学储存库(遥远的奥尔特云或较近的柯伊伯带)联系在一起，但单个彗星的一组检测到的分子提供了它们在原行星盘中形成彗星的位置的挥发性物质清单的“快照”。调查人员将使用地面近红外和无线电天文台，包括NASA红外望远镜设施、W·M·凯克天文台和阿塔卡马大毫米/亚毫米阵列。通过结合每个波长域的优势，研究人员的目标是测量不同分子物种之间的相对丰度，包括H2O、HDO、CH4、C2H2、C2H6、H2S、SO2、OCS、CO、H2CO、CH3OH、HCOOH、HCN、HNC、CH3CN、HC3N、NH2 CHO和NH3。计划对木星家族彗星和奥尔特云彗星进行新的观测。2017-2019年期间带来了多年来研究木星家族彗星的最佳机会-木星家族彗星是一个动态类别，在所有母体挥发物的组成研究中没有得到充分的代表。这些研究将被整合到一个天文馆项目中，该项目将在陶森大学沃森-金天文馆和圣路易斯大学密苏里大学的新数字天文馆举办，覆盖圣路易斯和巴尔的摩的学生，包括许多代表不足的少数族裔。一名调查员还将指导研究生和本科生。

Comets are early Solar System objects, mostly unchanged from the time the Solar System was created. The orbits of comets trace them to the locations in the outer Solar System where they formed. The compositions of molecules released from a comet can be measured by looking at their spectral signals. Combining these compositions with the comet orbits allows scientists to learn what materials were present at different locations in the early Solar System. The investigators will measure the amounts of many molecules in comet spectra, including H2O, HDO, CH4, C2H2, C2H6, H2S, SO2, OCS, CO, H2CO, CH3OH, HCOOH, HCN, HNC, CH3CN, HC3N, NH2CHO, and NH3. They will use ground-based observatories such as the NASA Infrared Telescope Facility, the W. M. Keck Observatory, and the Atacama Large Millimeter/submillimeter Array. The years of 2017-2019 provide an excellent opportunity to study Jupiter Family Comets - comets with smaller orbits for which little is known about their compositions. This research serves the national interest by advancing our knowledge of the materials that served as the building blocks of our Solar System. Shows at the Watson-King Planetarium, Towson University, and the University of Missouri, Saint Louis' new planetarium will feature this research. Students from St. Louis and Baltimore, including many minority students, will have the chance to see them. The Principal Investigators will use high-resolution molecular spectroscopy of comets to measure the compositions of volatiles released from their nuclei, and to test theories about the early formation of the Solar System. While the orbits of observed comets link them to their dynamical reservoir (the distant Oort cloud or closer Kuiper belt), the suite of detected molecules for an individual comet provides a "snapshot" of the volatile inventory at their location in the protoplanetary disk where these comets formed. The investigators will use ground-based near-infrared and radio observatories, including the NASA Infrared Telescope Facility, the W. M. Keck Observatory, and the Atacama Large Millimeter/submillimeter Array. By combining the advantages of each wavelength domain, the investigators' goal is to measure the relative abundances among various molecular species, including H2O, HDO, CH4, C2H2, C2H6, H2S, SO2, OCS, CO, H2CO, CH3OH, HCOOH, HCN, HNC, CH3CN, HC3N, NH2CHO, and NH3. New observations are planned of Jupiter Family comets and Oort cloud comets. The 2017-2019 period brings the best opportunity for many years to study Jupiter Family comets - a dynamical class underrepresented in compositional studies of all parent volatiles. These studies will be integrated into a planetarium program that will be hosted at the Watson-King Planetarium, Towson University, and at the University of Missouri, Saint Louis' new digital planetarium, reaching St. Louis and Baltimore students, including many underrepresented minorities. One investigator will also mentor graduate and undergraduate students.