Overview
- University of Zurich researchers led by Luca Morf and Ravit Helled report in Astronomy & Astrophysics that gravity data allow either rock-rich or water-rich interiors for both planets.
- The team’s hybrid approach iterates random interior density profiles against observed gravitational moments to construct physically consistent, assumption-light models.
- Model configurations include ionic-water layers capable of powering off-center dynamos that reproduce the planets’ complex, non-dipolar magnetic fields.
- In these solutions, Uranus’ dynamo region lies deeper than Neptune’s, offering a possible explanation for differences in their magnetic geometries.
- Current observations and uncertainties in high-pressure material behavior keep compositions degenerate, and the authors call for dedicated missions; one summary reports allowed rock-to-water mass ratios spanning about 0.04–4 for Uranus and about 0.20–under 2 for Neptune.