Glimpse of water's superionic state may explain icy giants' oddities

New experimental evidence that, at high temperature and extreme pressure, water can form a superionic state with both solid and liquid features has been obtained by US researchers. The results, which back up a 30-year-old prediction, could help explain the interior dynamics and magnetic fields of the icy giant planets, and may also be important for understanding some exoplanets. Since 1988, increasingly sophisticated computational models have suggested that ice heated at high pressures, but not to its melting point – which is nearly 5000°C at 200GPa, enters an ionically-conductive superionic state.