Searching for Subsurface Oceans on the Moons of Uranus Using Magnetic Induction

• Main Authors: Weiss, Benjamin P. (Author), Biersteker, John B. (Author), Colicci, Vittorio (Author), Goode, Allison (Author), Castillo‐Rogez, Julie C. (Author), Petropoulos, Anastassios E. (Author), Balint, Tibor S. (Author)
• Format: Article
• Language: English
• Published: American Geophysical Union (AGU), 2022-02-16T19:01:46Z.
• Subjects: Article
• Online Access: Get fulltext

The icy moons of Uranus may contain subsurface oceans. Such oceans could be detected and characterized using measurements of magnetic fields induced by Uranus' time-varying magnetospheric field. Here we explore this possibility for Uranus's five major moons, with a focus on Ariel. We find that the magnetic field at each moon is dominated by the synodic frequency with amplitudes ranging from ∼4 nT at Oberon up to ∼300 nT at Miranda. If these bodies contain oceans with sufficient thicknesses (>∼3-40 km) and conductivities (>2 S m−1) even underlying relatively thick (∼50 km) ice shells, the induced surface fields should have amplitudes exceeding the typical ∼1 nT sensitivity of spacecraft magnetometry investigations. Furthermore, the magnetic field variations at the moons span periods ranging from 1 to 103 h. These could enable long-term measurements to separately constrain ocean and ice thicknesses and ocean salinity.