Water on Earth is never truly still. Warmed by the sun, it evaporates from oceans, lakes, and damp soil and rises into the air as invisible vapor. As the vapor climbs and cools, it condenses around tiny particles of dust to form clouds. When the droplets grow heavy enough, they fall back to the surface as rain, snow, or hail. Some of that water runs off into streams and rivers, some soaks into the ground to feed springs and wells, and some is taken up by plants and released again through their leaves.
Click to start typing