# # Program information file # PROGRAM_ID 2022B997 PROGRAM_TITLE Uranus Stellar Occulation PROGRAM_INV1 Will Saunders PROGRAM_INV2 PROGRAM_INV3 PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT major planets / satellites PROGRAM_ABSTRACT_BEG Uranus has only been visited by one spacecraft, Voyager 2, in 1986. The data obtained by Voyager indicate a warm stratosphere and extremely hot thermosphere, at odds with dozens of Earth-based stellar occultations measurements. Serious limitations of both of these data sets is that they were made by instruments and analyzed by techniques considered rudimentary today. Observations of new Uranus stellar occultations on state-of-the-art instruments and analyzed with modern techniques will reveal a reliable thermal structure of the upper atmosphere of Uranus. We propose observing an occultation by Uranus on 2022-10-07 using MORIS and analyzing it to create a reliable temperature-pressure profile of the upper atmosphere of Uranus. Observations will be made in the K band to maximize the signal-to-noise and a cadence of 1-10 Hz will be used to maximize vertical resolution while minimizing additional sources of noise. IRTF is one of very few observatories that can observe with high cadence in the near infrared and the only one that faces Uranus during this occultation. PROGRAM_ABSTRACT_END