The Moon is estimated to be about 4.46 billion years old based on the most recent and advanced radiometric dating of lunar rocks, particularly zircon crystals brought back by the Apollo 17 mission
. This age is about 40 million years older than previous estimates, which placed the Moon's formation around 4.42 billion years ago
. However, there is some scientific debate about the exact age. Some studies suggest the Moon could be even older, approximately 4.51 billion years, forming shortly after the Earth itself from debris resulting from a giant impact with a Mars-sized body
. Other research proposes that the Moon's surface rocks, dated to about 4.35 billion years, may reflect a later "remelting" event caused by tidal heating from Earth, which reset the radiometric clocks of lunar rocks, thus masking the Moon's true, older age
. In summary:
- The widely accepted current age of the Moon is about 4.46 billion years old, based on lunar rock analysis
- Some evidence and models suggest the Moon could be as old as 4.51 billion years , forming soon after Earth
- The apparent younger ages of some lunar rocks (around 4.35 billion years) may be due to a global remelting event that reset their radiometric ages, not the Moon's actual formation time
This means the Moon likely formed very early in the solar system's history, roughly 100 to 200 million years after the solar system began forming about 4.57 billion years ago.
