What is the triple point of water?

The triple point of water: when water boils and freezes at the same time.

Imagine the moment when ice, water and vapor can exist together without completely transforming into each other.

This is the triple point of water – a unique state at a temperature of 0.01°C and a pressure of 6.11 mbar.

At the triple point, water behaves in a special way: ice does not melt completely, water does not evaporate completely, and vapor does not condense completely.

All three phases are in perfect equilibrium. The triple point of water serves as a reference for calibrating thermometers across the planet.

Interesting: on Mars, the pressure of the atmosphere is close to the pressure of the triple point of water.

Therefore, water on the surface of Mars can rapidly transition between ice and vapor, bypassing the liquid phase.