Question

The dark areas on the moon’s surface are called maria, Latin for “seas,” and were once thought to be bodies of water. In fact, the maria are not “seas” at all, but plains of solidified lava. Given that there is no atmosphere on the moon, how can you explain the absence of liquid water on the moon’s surface?

Short answer

All the water has vaporized, and thus, no liquid exists on the moon’s surface.

Step-by-step solution

Boiling point and pressure

The greater the pressure exerted by the atmosphere on the surface of a liquid, the greater will be its boiling point.

The moon does not have an atmosphere to exert pressure on a liquid.

Reason for no liquid water on the moon

For no or low pressure applied, the boiling point will be very low, sometimes equal to the moon’s atmospheric temperature.

Thus, all the atoms may have escaped because of this low boiling point or may have vaporized, leaving no liquid on the surface.

Hence, liquid water does not exist on the moon.