How old is Earth? How do scientists know how old Earth is? What is geologic time and how is time divided? What types of plants and animals lived in the past and how has life on Earth changed? What did Earth look like in the past and how to scientists know? Take a walk through the latest Eon of geologic time, and learn how Earth and Life have changed in these 541 million years.
Trek through Time in Reston, VA
The Trek Through Time is a short walk through the woods at the USGS National Center in Reston, VA. You can do it in person, or virtually, following this link.
Other Sites to Explore
Here are links to other ways to explore geologic time.