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Radiometric dating is a crucial method for estimating the age of Earth. This technique works by measuring the proportions of radioactive isotopes and their decay products within certain minerals in rocks. Understanding the decay of radioactive elements, such as uranium turning into lead, allows scientists to determine the age of rocks.
For instance, zircon crystals often contain uranium, and over time, this uranium decays into lead. By measuring the ratio of uranium to lead in these crystals, geologists have determined the age of the oldest rocks on Earth to be about 4.03 billion years.
This implies that the Earth is at least that old. By applying radiometric dating to various rocks and minerals, scientists can piece together an estimate of Earth's age, which aligns well with other evidence at about 4.56 billion years.

Meteorite dating is another method used to estimate the age of Earth. Meteorites are essentially leftover building blocks from the formation of our solar system. Scientists use radiometric dating on meteorites to measure their age.
The most accurate dates for these rocky bodies point to them having formed around 4.56 billion years ago. Since the Earth likely formed from the same solar nebula as these meteorites, this information provides a strong estimate for the Earth’s age.
This connection between meteorite dating and Earth's formation suggests they share a common time of origin, supporting the hypothesis that the Earth is roughly the same age as these ancient space rocks.

Lunar samples, collected from the surface of the Moon during the Apollo missions, also offer evidence about the Earth's age. These samples underwent radiometric dating just like those on Earth.
The resulting dates show these Moon rocks formed about 4.5 billion years ago. Since the Moon is believed to have formed shortly after Earth, likely due to a massive impact event, these dates align closely with predictions for Earth's age.
Consequently, both the dating of lunar samples and other terrestrial evidence such as meteorite dating and radiometric dating of Earth rocks consistently support an age for Earth of about 4.56 billion years.