The current estimate for the Earth’s age is around 4.54 billion years. Radiometric dating of the planet’s earliest rocks, minerals, and space meteorites forms the basis of this assessment.
Here’s how scientists estimate the Earth’s age:
Radiometric Dating
The principal method for determining Earth’s age is radiometric dating, which examines the decay of radioactive isotopes in rocks and minerals. Uranium-238 to Lead-206 and Uranium-235 to Lead-207 isotopes decay at known rates, as their half-life indicates.
For example:
Dating Meteorites
Earth’s rocks have been recycled through geological processes such as erosion and plate tectonics, making it difficult to identify truly ancient Earth rocks. Meteorites, which formed at the same time as Earth and the solar system, are better preserved. The Canyon Diablo meteorite, estimated at 4.56 billion years, provides an upper limit for Earth’s age.
Lunar Rocks
The Apollo missions returned rocks from the Moon that were 4.4 to 4.5 billion years old. These dates confirm the age of the Earth because the Moon most likely originated shortly after it.
These techniques consistently lead to Earth’s origin in the early phases of the solar system, approximately 4.54 billion years ago.