A new phase of superionic ice could exist under the particular conditions that exist on the planets Neptune and Uranus, according to theoretical research by at team at Princeton University. Chemist Salvatore Torquato describes superionic ice as an "in-between state of matter that we can’t really relate to anything we know". Unlike water or regular ice, superionic ice is made up of water molecules that have dissociated into charged atoms called ions, with the oxygen ions locked in a solid lattice and the hydrogen ions moving like the molecules in a liquid. He and his team describe details in the journal Nature Communications.
It's ice, but not as we know it