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Abstract

Titan, Saturn’s largest moon, is the only moon in the solar system to have a significant atmosphere. This is composed primarily of nitrogen (N2) and methane (CH4), which are decomposed under bombardment by the action of solar UV irradiation and Saturn magnetospheric electrons into radicals. These in turn react to form new chemical compounds, especially hydrogen cyanide (HCN), acetylene (C2H2) and ethane (C2H6). Spectroscopy of Titan’s atmosphere at near and mid-infrared (IR) wavelengths has historically contributed greatly to unraveling Titan’s atmospheric complexities including the measurement of temperature, gases and haze/aerosols. In 2022, a new era of infrared spectroscopy was enabled with the commissioning of the James Webb Space Telescope (JWST), with three instruments operating in the near-IR (1-5 microns) and one instrument operating in the far-infrared (5-28 microns). On November 4^th 2022, JWST acquired its first images and spectra of the trailing hemisphere of Titan. NIRSpec spectra show emission and absorption bands of CO, CH4, CH3D and HCN, with analysis and modeling work underway to further understand the data and search for other molecular signatures. The second phase of the project (GTO #1251) will happen around June 2023, when NIRCam and NIRSpec will again view Titan, this time on the leading hemisphere. In addition, the Mid-InfraRed Instrument (MIRI) will be used for the first time to take spectral images of Titan, with the Medium Resolution Spectroscopy (MRS) mode. In this presentation we will provide updates on the ongoing analysis of JWST spectra including the latest results.