Introduction

Evidence suggests that Earth and the rest of the solar system formed 4.5 to 4.6 billion years ago. Because of ongoing geological processes—such as plate tectonics and erosion—no record on Earth remains of its formation and early history. Therefore, scientists have to rely on data about other solar system objects that have not been altered by geological processes to learn about the solar system’s formation and early history. From that information, they can piece together what might have happened on Earth.

The following slides introduce some evidence sources that scientists can use to answer questions about Earth’s distant past.