Ages of Earth, Moon, and Sun

Earth is not 5–6 billion years old; it is about 4.54 billion years old. The Sun and Solar System began forming about 4.6 billion years ago. The Moon is also ancient and is generally associated with the early formation of the Earth–Moon system roughly 4.5 billion years ago, though its exact age depends on what is being dated—the Moon’s formation, its crust, or particular rock samples—and remains an active research question.