?  Library of Wonders The Wonder of  the Earth

Why doesn’t the Earth run out of water?

Have you ever wondered why the amount of water on Earth doesn’t run out? Or have you ever wondered whether the oceans will overflow? Interestingly, the amount of water on Earth always stays constant, not decreasing or overflowing. This is because water changes state and cycles around through many different places.

Water on the surface of the ocean is heated by the sun and turns into water vapor. The water vapor rises into the sky, where it cools and forms clouds. It then turns into rain or snow and falls back to the Earth’s surface. The water flows over the land, passes through rivers, and returns to the oceans again. This repeating cycle is called the water cycle. Water has been constantly traveling through the sky, land, and oceans for millions of years.