How long is an eon in years?

An eon is a significant unit of geological time. In terms of years, an eon typically spans about one billion years.

Understanding Eons in Geology

Geologists divide Earth's history into several time scales, and eons are the largest of these divisions. There are currently four recognized eons:

• Hadean - from the formation of Earth to about 4 billion years ago
• Archean - from about 4 billion to 2.5 billion years ago
• Proterozoic - from about 2.5 billion to 541 million years ago
• Phanerozoic - from 541 million years ago to the present

Importance of Eons

Eons help scientists understand the major events in Earth's history, including the formation of continents, the emergence of life, and significant climatic changes.