New Research Reveals the Moon Is Older Than Previously Believed
Recent research from scientists in the U.S., France, and Germany suggests the Moon formed as early as 4.53 billion years ago—hundreds of millions of years earlier than previously thought. This new timeline could explain lunar mysteries like the scarcity of massive impact basins and the Moon’s lower metal content compared to Earth, while offering fresh insights into Earth’s early evolution, according to geologist Francis Nimmo’s team.
The prevailing theory is that a Mars-sized object collided with a molten Earth, ejecting material that coalesced to form the Moon. Afterward, the Moon likely hosted a global magma ocean that cooled to create its surface. Previous estimates placed the Moon’s formation around 4.35 billion years ago, but recent findings from lunar zircon grains challenge this.
Zircon crystals provide a reliable method for determining the age of rocks. During their formation, these crystals incorporate uranium while rejecting lead. Over time, uranium decays into lead at a predictable rate, allowing scientists to accurately calculate the crystals’ ages by analyzing the uranium-to-lead ratios. Surprisingly, some lunar zircon crystals have been dated to 4.46 billion and even 4.51 billion years—much older than the 4.35-billion-year estimate for the Moon’s magma ocean. These findings suggest that zircon crystals predate the magma ocean, presenting a puzzling contradiction.
New Model Suggests Early Moon Formation and Tidal Heating Caused Crustal Remelting 4.35 Billion Years Ago
To resolve the inconsistency, Nimmo and his team propose that the Moon formed earlier than previously thought and underwent crustal remelting around 4.35 billion years ago, likely due to tidal heating from its early, eccentric orbit.
This timeline explains both the older zircon crystals and younger surface rocks, dating the Moon to between 4.43 and 4.53 billion years. Since Earth is about 4.54 billion years old, the Moon has been Earth’s companion almost its entire existence.
The findings also address lunar mysteries, such as fewer impact basins, which tidal remelting may have erased, and the Moon’s lower surface metal content, with early metals sinking below the surface. While this timeline provides answers, some mysteries remain—unless extraterrestrials scattered zircons for fun.
Read Original Article: Science Alert
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