The Science Case For Spacecraft Exploration Of The Uranian Satellites: Candidate Ocean Worlds In An Ice Giant System

Diagram showing the broad leading/trailing hemispherical trends in composition exhibited by Ariel, Umbriel, Titania, and Oberon, possibly driven by charged particle interactions (primarily with their trailing hemispheres) and heliocentric and planetocentric dust impacts (primarily with their leading hemispheres).

The 27 satellites of Uranus are enigmatic, with dark surfaces coated by material that could be rich in organics.

Voyager 2 imaged the southern hemispheres of Uranus' five largest 'classical' moons Miranda, Ariel, Umbriel, Titania, and Oberon, as well as the largest ring moon Puck, but their northern hemispheres were largely unobservable at the time of the flyby and were not imaged. Additionally, no spatially resolved datasets exist for the other 21 known moons, and their surface properties are essentially unknown. Because Voyager 2 was not equipped with a near-infrared mapping spectrometer, our knowledge of the Uranian moons' surface compositions, and the processes that modify them, is limited to disk-integrated datasets collected by ground- and space-based telescopes.

Nevertheless, images collected by the Imaging Science System on Voyager 2 and reflectance spectra collected by telescope facilities indicate that the five classical moons are candidate ocean worlds that might currently have, or had, liquid subsurface layers beneath their icy surfaces. To determine whether these moons are ocean worlds, and investigate Uranus' ring moons and irregular satellites, close-up observations and measurements made by instruments onboard a Uranus orbiter are needed.

Richard J. Cartwright, Chloe B. Beddingfield, Tom A. Nordheim, Catherine M. Elder, Julie C. Castillo-Rogez, Marc Neveu, Ali M. Bramson, Michael M. Sori, Bonnie J. Buratti, Robert T. Pappalardo, Joseph E. Roser, Ian J. Cohen, Erin J. Leonard, Anton I. Ermakov, Mark R. Showalter, William M. Grundy, Elizabeth P. Turtle, Mark D. Hofstadter

Comments: Accepted in AAS Planetary Science Journal. arXiv admin note: text overlap with arXiv:2007.07284
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2105.01164 [astro-ph.EP] (or arXiv:2105.01164v1 [astro-ph.EP] for this version)
Submission history
From: Richard Cartwright
[v1] Mon, 3 May 2021 20:42:52 UTC (8,024 KB)
Astrobiology, Astrochemistry,

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