That's a great question! While Earth is very old, 5 billion years is a bit too high.

Earth is approximately 4.54 billion years old.

Scientists have determined this age using various methods, including:

* Radiometric dating: This technique examines the decay of radioactive isotopes within rocks and minerals.

* Meteorite analysis: Meteorites are believed to be remnants of the early solar system, and their ages provide insights into Earth's formation.

So, while Earth is ancient, it's not quite 5 billion years old!