Speaker: Darek Lis, Jet Propulsion Laboratory, California Institute of Technology
Abstract: The far-infrared spectral range includes rotational transitions of light hydride molecules, such as water, as well as key fine-structure lines of neutral and ionized atoms. I will present a recent SOFIA spectroscopic study of atomic oxygen on the line of sight toward Sagittarius B2, and its implications for the overall oxygen budget in the diffuse and translucent spiral arm clouds. I will also review isotopic measurements of the D/H ratio in cometary water, carried out over the past 35 years with ground-based and space facilities, and their implications for the origin of Earth’s oceans. I will discuss prospects for continuing such measurements with future NASA facilities.