How long is an eon?

Question: How long is an eon?

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1 billion years.

In geology and related fields, an eon is the largest division of the geologic time scale. It is often defined as a unit of time equal to one billion years. However, in the context of geology, the precise length of an eon is not strictly fixed, and it can represent a significantly longer period of time, depending on the specific events and changes that took place during that eon.

The Earth’s history is divided into four eons: the Hadean, Archean, Proterozoic, and Phanerozoic. These eons represent major stages in the development of Earth and life on it.

In more casual usage, “eon” is often used to mean an indefinite or very long period of time.