Collaborative Research: Transformative studies of cometary volatiles in the era of modern near-infrared spectrographs

University Of Missouri-Saint Louis, Saint Louis MO

Investigators

Abstract

Comets are remnants from the early solar system that retain the volatiles (ices) from the cold regions where they formed. Their nuclei were among the first objects to accrete in the early solar nebula, and they likely formed at diverse distances from the young Sun. The primary science objective of this project is to better disentangle the natal (cosmogonic) heritage in cometary volatiles from signatures of possible post-formative processing. The project will use high-resolution, near-infrared spectroscopic observations of comets to advance understanding of the compositional measurements of volatiles released from their nuclei and connect comets to natal conditions in the early solar system. The project integrates the research into professional development of STEM teachers following the Next Generation Science Standards, in mentoring undergraduate students, and in supporting a graduate student to build a peer mentorship network between STEM departments. A sequence of very favorable upcoming cometary apparitions presents a timely opportunity for potentially transformative studies of comets as unique volatile-rich remnants from the early solar system. The project will use IR spectroscopy of sufficiently high spectral resolution (~20,000 or higher) to measure distinct rotational-vibrational emissions from parent molecules released into the comae of comets. Measuring the strengths of and applying fluorescence modeling to these emissions enables the determination of the production rates [molecules/s] for many species: CH4, C2H2, C2H6, CO, H2CO, CH3OH, OCS, NH3, HCN, and H2O. Relative abundances (e.g., C2H2/C2H6) are then expressed as the ratios of production rates. The project will also measure coma spatial distributions of gas column density, which are highly diagnostic for connecting measured composition with the outgassing sources of individual volatiles. The project has the potential for improving our understanding of planetary system formation as well. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.