Frozen Oort Cloud Comet Hale-Bopp

We propose to observe the Great Comet C/1995 O1 (Hale-Bopp) at 46 au from the Sun, distances where many surface ices are thermally stable. With a modest 11.2 hr program, a near-infrared spectrum can be obtained, providing key physical information on the composition of cold cometary surfaces. This wavelength range contains diagnostic spectral features from water, CO2, and methanol ice. Such data would enable studies of cometary volatiles in a unique context: on the surface of an Oort cloud comet at distances equivalent to the Kuiper Belt. No other observatory can spectroscopically observe Hale-Bopp in the near-infrared, and no other comet will be observable at this distance in JWST's lifetime. This, and future studies of cometary surfaces with JWST, will lay the groundwork that, together with spacecraft missions to comets, will enable us to assess cometary nuclei under a wide range of physical circumstances.