Unlike other planets in our solar system, Uranus and Venus have asymmetrical magnetic fields that are not aligned with their north-south axes. Most planets' magnetic fields are created by their spinning metallic cores. Scientists have hypothesized that the ice giants’ irregular fields might result from an additional shell of metallic liquid moving around their cores, but they had little evidence about what that shell might be. New simulations suggest that H3O could exist as a metallic fluid at the temperatures and pressures found inside these planets (Proc. Natl. Acad. Sci. U.S.A. 2020, DOI: 10.1073/pnas.1921811117). Russell Hemley of the University of Illinois at Chicago modeled the behavior of hydrogen and oxygen at a range of conditions similar to those in the planets’ interiors and found stable solid and liquid forms of H3O that others had overlooked.