The Quiz: In the context of astronomy, how many years are in an eon?
100 years
1,000 years
1 million years
1 billion years
In everyday conversation, an eon is frequently used as a term to exaggerate how long something took, much the same way the words “forever” and “ages” are used. However, when used in the context of science, particularly astronomy, an eon can be defined a precise unit of time. While a century is 100 years, and a millennium is 1,000 years, neither is even remotely as close to the length of an eon. For an eon to pass, you will need to wait a billion years. The word eon dates back to the greek word aion, which means “age.”
The correct answer to this quiz is 1 billion years.