Julius Edgar Lilienfeld Prize (2021): Evolution of Laboratory Astrochemistry of Comets and Other Astronomical Bodies Over the Past Sixty Years
COFFEE_KLATCH · Invited
Abstract
Astrochemistry is the study of the elementary chemical reactions that produce and destroy the molecules observed in astronomy. Sixty years ago, there were only a few atoms, diatomic, and triatomic molecules observed in astronomy. Most of these were in comets such as O, Na, K C2,CN, OH, CO+, OH+, N2+, C3, NH2, and CO2+ through their emission spectra excited by resonance fluorescence of sunlight in the atmosphere surrounding a comet. In this atmosphere there is also gas, dust and magnetic fields. The laboratory studies of the spectroscopy of these species had been known for a long time and it was also known that the atoms and radicals could not be stored for long periods of time, even at liquid He temperatures. If they are not evaporating from the cometary nucleus, how are they being produced? The method of production has to be consistent with the astronomical environment they are found in. I will chronicle how certain laboratory techniques have helped us to determine the precursors of some atoms and radicals observed in comets, planetary atmospheres and other astronomical bodies.
*This work has been supported over the years by NASA Goddard Space Flight Center (GSFC) and grants from NASA, Chemistry Division of NSF, Basic Energy Sciences of Department of Energy and the Office of Naval Research. It was done during my tenure at GSFC, Howard University, and the University of California, Davis as well as many institutions around the world that I have had the opportunity to work in. It could not have been done without the collaboration with a variety of colleagues, students, postdocs and faculty that I have had the pleasure to work with.
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