Recent research suggests that the Moon may be older than previously thought, with samples indicating it formed around 4.35 billion years ago. However, this timeline poses challenges, as the chaotic early solar system likely made such a late collision improbable. To address this discrepancy, UC Santa Cruz Professor Francis Nimmo and colleagues propose that tidal heating may have caused a global “remelting” of the Moon’s surface around this time, effectively resetting the geological clock and masking its true age.
This phenomenon, akin to a volcanic facelift, means that lunar rocks do not exceed 4.35 billion years, as they would have been altered by this tidal heating. Supporting this theory is the comparison to volcanic activity on Jupiter’s moon Io, driven by similar tidal forces. Current models suggest that significant tidal heating influences altered the Moon’s geology, potentially placing its formation between 4.43 and 4.53 billion years ago. Excitement grows with upcoming lunar missions, such as China’s Chang’e 6, which may provide samples to further investigate this remelting hypothesis. Overall, these findings could significantly reshape our understanding of the Moon’s formation and its history in the solar system.
