Today, you are going to learn all about rocks. The first thing you should know about rocks is that the people who study them are known as geologists . And, just like doctors, geologists have specialties.
Historical geologists look at the formation and evolution of the Earth and life on Earth.
Physical geologists study what materials the Earth is made of, and what's happening on and beneath the Earth's surface. It was here even before your great-grandparents were born. In fact, the earth is older than the first humans. If there was no Earth when the first humans were born, then they would've just fallen through space. Anyway, the Earth is really old.