Geologic time scale

The geologic time scale is like a huge clock that tells us how old Earth is and how long ago different kinds of living things lived. It helps scientists understand how different kinds of rocks formed and how different kinds of living things evolved over time. The geologic time scale is divided up into different sections like seconds, minutes and hours on a clock. But instead of seconds and minutes and hours, it's divided up into eras, periods and epochs. An era is like an hour and it lasts for tens of millions of years. A period is like a minute and it lasts for several million years. An epoch is like a second and it lasts for thousands of years. Together, the geologic time scale helps us understand how old different kinds of rocks and fossils are, and how different kinds of living things have evolved over time.