The Amazing Journey of Water

Have you ever wondered where rain comes from? Every drop of water on Earth is on a never-ending journey called the water cycle. The same water has been travelling around our planet for billions of years — the water in your glass may once have been in a dinosaur’s puddle!

It all starts when the Sun heats up oceans, lakes and rivers. The water slowly turns into an invisible gas called water vapour and floats up into the sky. This is called evaporation. You can see a mini version of it when a puddle disappears on a sunny day.

High above us, the air is much colder. The water vapour cools down and turns into tiny droplets that cling together around dust particles. Billions of these droplets make a cloud. This part of the journey is called condensation.

When the droplets inside a cloud grow bigger and heavier, they fall back to Earth as rain, snow, sleet or hail. Scientists call this precipitation.

Once the water lands, it soaks into the ground or rushes into streams and rivers that flow back to the sea. Then the whole journey starts all over again — and it never, ever stops.