All the water on earth is the same water that has been here throughout history! Water is never created; it is continuously cycling in a process called the water cycle. This cycle describes the continuous changes of water on, in, and above the earth as it transforms from liquid to vapor to ice over and over again. All life on earth relies on the continuous functioning of the water cycle, and earth has been cycling its water successfully for billions of years.
Studying the water cycle opens up a host of science topics for students to learn about, including the processes of evaporation, condensation, precipitation and infiltration that help comprise the water cycle, as well as topics such as clouds and weather, atmosphere and climatology, glaciers and oceans, and aquifers and groundwater.