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Miranda is the only icy body whose surface is known to contain the enigmatic features called corona—ovoid to trapezoidal areas of deformation. In this work, we seek to constrain potential formation mechanisms for Inverness Corona, the youngest known region on Miranda. To do this, we created the first detailed geologic map of Inverness, enabling the creation of a stratigraphic column of the order of events that formed this region. We employed a previously published Digital Elevation Model of the northern region of Inverness Corona to analyze the spacing of features in the region, which we propose to be extensional in origin. From this, we estimate an approximate brittle ice shell thickness of 2.5–3.8 km at the time of the region’s formation, indicating that Miranda’s brittle ice shell may have been relatively thin in the geologically recent past. We propose that Inverness formed from extension driven by a rising diapir or ice-shell thickening from a recent orbital resonance with Umbriel. The Uranus Orbiter and Probe mission is the highest priority flagship mission recommendation of the 2023–2032 Planetary Science and Astrobiology Decadal Survey. As such, we suggest measurements related to imaging, composition, gravity, and ice-shell thickness to gain an understanding of the geologic and orbital histories of the Uranian satellites, which would have implications for the evolution of the system as a whole.

We investigated how lithospheric heat fluxes varied temporally and spatially on the Saturnian moon Tethys, focusing on the region of Ithaca Chasma that overprints Telemus Impact Basin. Our results, derived from flexure associated with Ithaca, indicate elastic thicknesses of 4.1 ± 0.3 km to 6.4 ± 0.4 km and heat fluxes ranging from 12 to 39 mW m ^−2 assuming a nonporous pure H _2 O ice lithosphere. Our results for Ithaca’s south limb are similar to previous estimates within the north limb, indicating consistent heat fluxes across a large spatial extent in this area. However, our estimates are lower than those for the older Telemus Basin (>60 mW m ^−2 ), revealing evidence that Tethys experienced a substantial temporal variation in heat fluxes in this region. Heat fluxes reflected by Ithaca are similar to previous estimates for Tethys’s two youngest impact basins, Melanthius and Odysseus, suggesting that Ithaca may also be relatively young. If Tethys’s lithosphere is porous, then our heat flux estimates for Ithaca Chasma drop to 12–38 mW m ^−2 , 11–35 mW m ^−2 , and 10–33 mW m ^−2 for 5%, 15%, and 25% porosities, respectively. If Tethys’s lithosphere includes ∼10% NH _3 -hydrates, then the estimates are 5–16 mW m ^−2 , 5–15 mW m ^−2 , 4–14 mW m ^−2 , and 4–13 mW m ^−2 for 0%, 5%, 15%, and 25% porosities, respectively. Although we find that some ground-based reflectance spectra hint at 2.2 μ m bands that may result from NH _3 -bearing species, the detected features are weak and may not result from surface constituents. Consequently, our heat flux estimates that assume a pure H _2 O ice lithosphere are likely more accurate.

Messina Chasmata is a relatively young tectonic structure on Titania based on cross-cutting relationships, although an absolute age has not been estimated. We investigated lithospheric flexure bounding Messina and found that the terrain along both rims reflects Titania’s thermal properties. We estimate Titania’s heat fluxes to have been 5–12 mW m ^−2 in this region, assuming that the lithosphere is composed of pure H _2 O ice without porosity. These estimates are lower if lithospheric porosity and/or NH _3 –H _2 O are also present. If Messina is ancient, forming as a result of freeze expansion, then the reflected heat fluxes are consistent with radiogenic heating. However, if Messina is instead young, then an additional heat source is required. In this scenario, perhaps tidal heating associated with the past three-body resonance shared between Titania, Ariel, and Umbriel generated this heat. However, this scenario is unlikely because the amount of tidal heating produced on Titania would have been minimal. Titania’s heat fluxes are notably lower than estimates for Miranda or Ariel, and future work is needed to investigate Umbriel and Oberon to gain a fuller understanding of Uranian moon thermal and orbital histories. Additionally, further constraints on Titania’s more ancient heat fluxes could be obtained by investigating relatively older features, such as some viscously relaxed impact craters.