Ice hotter than 3,600 degrees Fahrenheit? It’s easier to imagine a kitchen sponge being instantly vaporized in an oven this hot. But scientists recently confirmed that a particular kind of ice could exist in a lab as a mix of solid and liquid at such temperatures given high enough pressure to crush anything not properly contained.
The article discusses a new state of this unusual ice which would only form at such high temperatures and pressures. The new ice structure has oxygen atoms forming a hexagonal crystalline lattice while the hydrogen ions are free to move as if the liquid was poured into a solid. The movement of these ions allow the substance to conduct electricity which normal ice does not possess.
A team led by Alexis Forestier of France’s CEA compressed microscopic water samples inside laser-heated diamond-anvil cells. Pressures climbed to roughly 219–230 gigapascals more than two million atmospheres. Lasers pushed temperatures as high as 2,630 K, or about 4,274°F.
Synchrotron X-ray diffraction at the European Synchrotron Radiation Facility revealed the structure. At lower conditions within the superionic regime, a face-centered cubic arrangement of oxygen atoms dominated. At 219 GPa and 2,630 K, the hexagonal close-packed (hcp) form took over, its diffraction peaks clearly outshining the older pattern. The transition matches long-standing theoretical predictions of a martensitic shift between the two close-packed lattices.
The findings appeared in Physical Review Letters on September 9, 2026. Superionic ice itself had been produced and studied before; the breakthrough here is the first unambiguous experimental identification of the hcp phase at these extremes.
These pressures and temperatures exist deep inside Uranus and Neptune. Models suggest thick layers of superionic ice in their mantles. The mobile protons can carry electric current, offering a plausible explanation for the planets’ strange, tilted, and off-center magnetic fields quite unlike Earth’s deep dynamo.
Viral posts describing it as “ice that survives at 3,600°F” do it an injustice, but the claim it’s a “new” chemical substance is also misleading; the material isn’t something you’d see everyday at home, but it is still just good old Hâ‚‚O that has been forced into a different state by extreme pressure that would be impossible to observe outside of an astromony laboratory or in the core of a planet.
The discovery is a valuable addition to the phase diagram of water and helps contextualize the ice giants in our solar system.
Future work will no doubt press on, defining the boundaries of it’s conductivity and stability, but as for the actual lab sample, the scientists can confirm that given the right conditions, ice will indeed withstand temperatures of over three thousand six hundred degrees Fahrenheit.
