Boiling oceans may sculpt the surfaces of small icy moons

Computer simulations reveal that small icy moons in the outer solar system may experience boiling in their subsurface oceans when gravitational heating thins their ice shells, reducing pressure enough for water to reach its triple point at zero degrees Celsius. This boiling creates gas-filled cracks that form visible surface features like ridges on Uranus' moon Miranda, while thicker ice shells on moons like Saturn's Mimas prevent such features. The phenomenon only affects moons smaller than 600 kilometers across, as larger bodies would crack before reaching boiling conditions.