IRTF Data Archive Program Information

# # Program information file # PROGRAM_ID 2023B071 PROGRAM_TITLE Spectral Image Cubes of Venus in Conjunction with Akatsuki Observations PROGRAM_INV1 Eliot Young PROGRAM_INV2 Mark Bullock PROGRAM_INV3 Kandice Lea Jessup PROGRAM_INV4 Toru Kouyama PROGRAM_INV5 Kevin McGouldrick PROGRAM_SCICAT major planets / satellites PROGRAM_ABSTRACT_BEG Venus has an inferior conjunction on August 13, 2023, when its disk will be large [up to 58'] and predominantly night. By scanning the SpeX long slit across Venus's disk, we can obtain image cubes of Venus's nightside, where selected wavelengths regions [1.18, 1.26, 1.31, 1.74, 2.2 - 2.45 um] represent CO2 windows. These windows are sensitive to thermal photons from Venus's surface and lower two scale heights. Nightside clouds in Venus's lower and middle cloud decks [48 - 55 km altitude] show up as silhouettes against the upwelling thermal radiation, and several trace gases [CO, OCS, H2O] will be detected in the 1.74 and 2.2 - 2.45 um windows. SpeX spectra let us fit for cloud opacities, particle sizes, and the distribution of trace gases, all of which bear on the interconnected dynamics, chemistry and microphysics of Venus's atmosphere. In addition, GuideDog imaging at 2.26 and 1.74 um lets us track clouds, and 5.1 um images are sensitive to mountain waves that are launched from topographic highs. In addition, image cubes show oxygen airglow at 1.27 um, which emanates from 95 km altitude and serves as a tracer of winds in Venus's mesosphere. Akatsuki no longer has its IR1 and IR2 cameras [and it never had spectral capabilities], but the SpeX image cubes will complement the UV [at 283 and 365 nm] and LIR [8 - 12 um] cameras on the spacecraft. PROGRAM_ABSTRACT_END