Metallic trihydrogen oxide could explain ice giants’ strange magnetic fields

Trihydrogen oxide (H₃O) – a metallic liquid stable at extreme pressures and temperatures – could be what’s powering the strangely wonky magnetic fields of Neptune and Uranus.

The planets’ magnetic field is offset from the their physical centre and strongly tilted relative to their rotational axes – 47° on Neptune and 59° on Uranus. Whereas Earth’s magnetosphere is generated in its molten iron core, neither Uranus nor Neptune has such a structure. Both ice giants are thought to contain a solid core surrounded by a metallic liquid layer powering an internal dynamo. But the nature of this layer remained elusive.