How Old Is the Earth Really?

As of 2014, scientists believe the Earth to be 4.54 billion years old, plus or minus 50 million years. This measurement was calculated using radiometric dating techniques on rocks found on Earth, samples from the Moon and meteorites from elsewhere in the Solar System.

The landscape of the Earth has been constantly eroded and resurfaced through weather and geological processes, and the oldest rocks native to the Earth have been dated between 3.4 and 3.8 billion years old. However, the Moon has no atmosphere and no active geology to upset or resurface the rocks there, and the lunar missions returned samples that were dated between 4.4 and 4.5 billion years, helping to provide a more accurate measurement for the age of the Earth.