The Water Cycle: How Earth Recycles Water
The same water, cycling for billions of years
The same water, cycling for billions of years
Watch water particles journey through all four stages: evaporation from the ocean, condensation into clouds, precipitation as rain, and collection back into water bodies. The cycle never stops.
Click each stage to zoom in and see the molecular-level process.
Water is the most remarkable substance on Earth.
Earth has had roughly the same amount of water for 4 billion years. The water in your glass has been through dinosaurs, volcanoes, glaciers, and countless clouds.
97% of Earth's water is in the oceans (salt water). 2% is frozen in ice caps. Only 1% is fresh liquid water available for drinking, farming, and industry.
Rivers carve canyons, glaciers flatten mountains, rain erodes soil. Over millions of years, the water cycle has sculpted every landscape on Earth.
A single water molecule spends an average of 9 days in the atmosphere, 2 weeks in a river, 100 years in a lake, and 3,000 years in the ocean before evaporating again. The cycle is patient.
You've traced water through its endless journey: evaporation lifts it up, condensation forms clouds, precipitation brings it down, and collection gathers it to start again. The water you drink today is the same water dinosaurs drank.
Heat from the Sun turns liquid water into water vapor (gas). It rises because warm air is lighter. Oceans, lakes, and rivers all contribute.
As vapor rises and cools, it condenses into tiny water droplets around dust particles. Billions of droplets clump together to form clouds.
When droplets grow heavy enough, gravity pulls them down as rain, snow, sleet, or hail. What form depends on temperature.
Water flows into rivers, lakes, oceans, and underground aquifers. Then the Sun heats it and the cycle begins again. Endlessly.
Put your new knowledge into practice!