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

彗星是早期的太阳系天体，从太阳系形成时起，大部分都没有变化。彗星的轨道可以追踪到它们在外太阳系形成的位置。从彗星释放的分子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，科学家们可以了解早期太阳系不同位置存在的物质。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、NH2CHO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型毫米/亚毫米阵列。2017-2019年是研究木星家族彗星的绝佳机会，这些彗星的轨道较小，对其成分知之甚少。这项研究通过提高我们对构成太阳系的材料的认识，为国家利益服务。陶森大学沃森-金天文馆和圣路易斯密苏里大学新天文馆的展览将以这项研究为特色。来自圣路易斯和巴尔的摩的学生，包括许多少数族裔学生，将有机会看到它们。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核中释放的挥发物的成分，并测试有关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态储存库（遥远的奥尔特云或更近的柯伊伯带）联系在一起，但单个彗星的检测到的分子组提供了一个“快照”，显示了这些彗星形成的原行星盘中它们所在位置的挥发性库存。研究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. Keck天文台和阿塔卡马大型毫米/亚毫米阵列。通过结合各个波长域的优势，研究人员的目标是测量各种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、NH2CHO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年是多年来研究木星家族彗星的最佳时机，这是一个在所有母体挥发物成分研究中代表性不足的动态类别。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的沃森-金天文馆和密苏里大学圣路易斯分校的新数字天文馆举办，面向圣路易斯和巴尔的摩的学生，包括许多未被充分代表的少数民族。一名研究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.