0 Assigned ID: 5874 ----- Attempting Submission 1 (Tue Mar 26 23:54:58 GMT 2024) ----- HST Phase I Proposal 5874 successfully submitted. Receipt: # 5874-1 ----- Attempting Submission 2 (Tue Mar 26 23:58:32 GMT 2024) ----- The lack of apparent heat release from deep within Uranus's interior is a major oustanding question in planetary science, and one a future orbiter/probe mission will likely seek to address. However, a current knowledge gap on the role of absorbed Solar radiation in Uranus's energy budget restricts our ability to determine an accurate determination of the amount of released internal heat, thereby restricting our ability to test solutions to this problem. We therefore propose to utilize archived HST observations of Uranus to derive new estimates of Bond albedo at regular 2-3 year intervals between 1994 and 2023, allowing us to inspect any possible temporal variability in reflectivity and place constraints on the true degree of heat release at Uranus. Emma Dahl, the PI of this proposal, is highly experienced in observing, data reduction, and conducting radiative transfer modeling of giant planet atmospheres in the optical and near-infrared wavelength regimes in order to characterize tropospheric and stratospheric clouds and hazes. She has a great deal of experience disentangling parameter degeneracies within these wavelength regimes in order to accurately deduce atmospheric characteristics. Amy Simon has more than 25 years' experience in analyzing and interpreting planetary atmospheres data, including visible and infrared imaging and spectroscopic data from Voyager, Galileo, Hubble and Cassini. She is PI of the Hubble Outer Planet Atmospheres Legacy program and will help cross-coordinate analyses between OPAL and this program. Patrick Irwin is an expert in radiative transfer and retrieval analysis from remotely observed spectral observations of planetary atmospheres. He has published numerous papers analyzing near-infrared observations of Uranus and Neptune from ground-based telescopes, including UKIRT, Gemini, ITRF and VLT. The observations recorded by this programme will be analysed with Irwin's radiative transfer and retrieval code, NEMESIS. Solar System Astronomy 0 false false false false false false false SUPPORTED