Scientists believe the Earth was formed around 4.54 billion years ago. This age is determined through various methods, including:

* Radiometric dating: This method uses the decay rates of radioactive isotopes found in rocks and meteorites to calculate their age.

* Lunar samples: Analyzing rocks brought back from the Moon by Apollo missions has provided valuable insights into the early solar system and the Earth's formation.

* Meteorites: Studying the composition and age of meteorites, which are remnants from the early solar system, helps us understand the processes that led to Earth's formation.

While the exact date is still being refined, the scientific consensus points to the Earth being formed roughly 4.54 billion years ago.