Erosion has a great impact on the geology of a planet. It wears rock and soil away and changes the landscape. Agents of erosion include water, ice, wind, and chemical action. On this page, let's look at some of the processes that break up rocks and carry soil away. Rain Rain drops are formed when water vapor in the air condenses around tiny dust particles or ice crystals.
Clouds form as the drops of water grow.
As rain falls, it returns evaporated water to the surface of the planet, scattering it over the land masses so that plants can grow nearly everywhere on earth. Humans live in places with 20 inches or more of rainfall a year, though they can survive with less if they use irrigation or very special dry land farming practices that capture water and deliver it to the roots of their crop plants. When rain falls on the ground some of it soaks into the soil. It moistens the soil particles and makes them easier to move. A heavy rain will stir up the surface of the soil and make mud of the small particles.