A closed bottle containing water at 30 degree celsius is carried to the moon in a spaceship. If it is placed on the surface on moon, the water boils. Why?
Let us consider first the ideal gas equation, PV = nRT. Notice that Pressure is directly proportional with the temperature.
With this relationship, we can see that as pressure increase, the temperature increases as well. Also, as the pressure is decreased, the temperature decreases as well.
Relating it with the boiling point of water at much lower temperature, boiling point is dependent on the air pressure. It also means that the lower the air pressure, the lower the boiling point. Moon essentially has no atmosphere and has very low pressure compared with the earth's properties.
You can also see this phenomenon even without flying to the moon. Boling point of water in high altitude areas (high mountains) is lower compared in the low lands or sea level.