There are thousands of different kinds of rocks on Earth. But how did they all get there? Most of the rocks around us are millions of years old, and they are always changing into new ones. In fact, it's happening right now—deep beneath your feet! Explore the three main types of rocks that make up the rock cycle with colorful and illustrative diagrams. A final science lab activity engages young readers to get creative with what they've learned. It's a rockin' good time on Earth!