Ingredients for Life Abound in Comets: a look at the variety of cometary organic matter

January 24, 2022
Thematic Seminar: Cosmochemistry
Dr. Lori Feaga, University of Maryland

A wide variety of organics have been discovered and inventoried in the cometary environment, from simple carbon chain molecules like methane to much more complex molecules like benzene and butanol. In situ mass spectrometers, like the suite of instruments on Vega 1 and Giotto that flew past comet 1P/Halley and  ROSINA onboard Rosetta to comet 67P/Churyumov-Gerasimenko, remote infrared spectrometers, like the HRI-IR on Deep Impact and VIRTIS flown on Rosetta, as well as ground-based campaigns and surveys, have measured the abundances of organic constituents in comets for over four decades. In doing so, clues as to the conditions of formation and the composition of the protoplanetary disk from which comets and the planets formed have been revealed. With comets being small, non-differentiated bodies spending most of their lifetimes in cold storage reservoirs in the outer Solar System, they undergo less thermal alteration and fewer processing mechanisms than many other Solar System bodies, leaving their interiors as some of the most intact primordial material. The release of the subsurface material via sublimation into the coma gives access to measuring these materials and sheds light on our origin. In this talk, Dr. Feaga will briefly revisit some historical cometary organic measurements in light of recent findings, present the current state of knowledge regarding the inventory of organic matter, noble gases, amino acids, and phosphorous in comets, and discuss implications of some of these and other recent unique discoveries.