Almost four decades after the lone in-situ encounter of the Uranian system by the Voyager 2 spacecraft, our understanding of the system is still significantly lacking with many more open questions than answers. This is increasingly true as the community sets its sights towards future exploration of the system and revisits previous analyses and conclusions armed with new insights based on orbital investigations from other planets such as Jupiter and Saturn, new modeling capabilities, and new remoted sensing datasets from assets such as Hubble and JWST. This workshop aims to bring together leading experts across the planetary science community to review recent results in the context of our current understanding of the Uranian system, as well as the knowledge from other planetary and exoplanetary systems, to identify the major unsolved mysteries that would need to be addressed by future investigations.
Uranus presents a compelling scientific target for the planetary science community, providing a unique opportunity to explore an ice giant system with its five classical satellites, which boast drastic surface features, and dynamically full and apparently haphazard system of rings and small moons, in addition to the planetary and magnetospheric effects of its highly tilted rotational axis being almost in Uranus’s orbital plane and its strongly multipolar intrinsic magnetic field. In particular, new results over the past few years have renewed much debate over significant outstanding questions about the system. First, it is unclear where and when the Uranus system formed. Many solar system formation models struggle to produce the current planetary configuration without strongly bound initial conditions. Similarly, questions remain as to how the planet’s dense rings and numerous moons formed and what processes dominate their dynamics, let alone how the system was affected and evolved after whatever cataclysmic event knocked the planet onto its side. Another ongoing debate surrounds whether any of the classical moons in the system may be potential ocean worlds, as a growing body of new evidence, based on a combination of the reanalysis of Voyager 2 measurements, new spectral observations from JWST, and new modeling studies, may suggest. Finally, new debate has arisen around the nature and characteristics of the Uranian magnetosphere with new results suggesting that the notably low plasma densities observed by Voyager 2 may be a result of anomalously strong solar wind pressure and/or the plasma dynamics driven by the planet’s extremely high obliquity and the strong tilt of its magnetic field.
This workshop will review progress in our modern understanding of the Uranian system, based on new observations and simulations, the reanalysis of Voyager 2 data, and knowledge gained from other Giant planet systems, while also considering broader cross-disciplinary applications. The purpose of this is to produce the first dedicated ISSI reference work on the Uranian system, targeting the broad planetary science research community. The Topical Collection in Space Science Review resp printed Volume in the Space Science Series of ISSI resulting from this Workshop would be especially timely to help outline the potential open questions for future investigations and serve as a great resource to new researchers.
Header Image Credit: NASA/Johns Hopkins APL/Mike Yakovlev