Recent research indicates that the Moon might be approximately 4.51 billion years old, which is 160 million years older than previously estimated. This revelation arises from an analysis of lunar samples and the effects of tidal heating on its geological history.
The Moon's formation has long been attributed to a collision between the early Earth and a Mars-sized protoplanet named Theia. Conventional estimates placed the Moon's age at 4.35 billion years, suggesting it formed about 200 million years after the solar system.
However, discrepancies in age estimates have led scientists to investigate further. A study published in the journal Nature proposes that tidal forces, acting on the Moon shortly after its formation, caused significant geological changes. These tidal forces likely resulted in a remelting event that obscured the Moon's true age.
Researchers from the University of California at Santa Cruz and other institutions suggest that the intense gravitational interactions between the Earth and the Moon during its early history led to volcanic activity, reshaping its surface and resetting the ages of lunar rocks.
Notably, zircon minerals found on the lunar surface hint at an older formation age, potentially aligning with the new estimates. The study draws parallels with Io, a moon of Jupiter, which experiences similar tidal heating and volcanic activity.
The findings imply that the Moon's surface has been significantly altered, erasing evidence of earlier impacts and leading to the conclusion that the Moon's geological clock was reset around 4.35 billion years ago.
As upcoming missions, such as China's Chang'e 6, aim to explore new lunar regions, researchers anticipate that fresh samples will provide further insights into the Moon's history and age.