The discovery will help researchers understand the history and evolution of the moon.
The moon is 40 million years older than previously thought, the results of a fresh analysis of its crystals has indicated. These samples were brought to Earth by Apollo astronauts in the 1970s. They have been analysed several times, but a new study, carried out by researchers at the Field Museum and the University of Glasgow, threw fresh light on the age of the oldest crystal, revealing it is 4.46 billion years old, rather than 4.52 billion years old as previously estimated.
The study has been published in the journal Geochemical Perspectives Letters.
"It's amazing being able to have proof that the rock you're holding is the oldest bit of the moon we've found so far. It's an anchor point for so many questions about the Earth. When you know how old something is, you can better understand what has happened to it in its history," The Guardian quoted lead author Dr Jennika Greer of the University of Glasgow as saying.
The discovery was made possible by a new approach known as atom probe tomography, which involves using a laser to evaporate atoms from crystals that have been sharpened to a very fine "nano tip".
The atom-by-atom analysis allowed researchers to count how many atoms in the moon's crystals have undergone radioactive decay.
Scientists said a more precise age will help them better understand the history and evolution of the moon, as well as Earth.
"Without the moon, life on Earth would look different," study co-author Philipp Heck, a professor at the University of Chicago, said in a statement. "It's a part of our natural system that we want to better understand, and our study provides a tiny puzzle piece in that whole picture."
The popular theory around moon's formation is the giant-impact hypothesis that suggests at some point in Earth's very early history, these two bodies collided. The blasted-out material, bounded by its own gravity, then created the moon as we see today.
However, when did this collision occur and how long the moon formation took has remained a question so far.