New lunar dust analysis shows Moon 40 mn years older than believed

WEB DESK: In a groundbreaking revelation, lunar dust samples collected by NASA’s Apollo 17 mission in the 1970s have challenged previous beliefs about the age of the Moon.

According to CNN, recent analysis has unveiled that our celestial neighbour is approximately 40 million years older than scientists initially thought.

Astronauts Eugene Cernan and Harrison Schmitt, during their historic moon landing on December 11 1972, gathered rocks and dust from the lunar surface. These samples, meticulously preserved for decades, have now yielded invaluable insights into the Moon’s age.

A fresh examination of these specimens uncovered zircon crystals, which, when dated, were found to be approximately 4.46 billion years old, slightly older than the previous estimate of 4.425 billion years. The significant revelation has been published in the journal “Geochemical Perspectives Letters.”

Meanwhile, Dr Philipp Heck, the Robert A. Pritzker Curator for Meteoritics and Polar Studies at the Field Museum of Natural History in Chicago and the senior author of the study, stressed the importance of the ancient crystals.

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“These crystals are the oldest known solids that formed after the giant impact. And because we know how old these crystals are, they serve as an anchor for the lunar chronology,” said Heck.

According to the media reports, the Moon’s formation, a result of a colossal celestial collision with Earth, has long been a subject of scientific inquiry. The impact of a Mars-size object striking Earth over 4 billion years ago gave birth to the Moon. Having said that a wild guess can be taken regarding age of the Moon.

However, pinpointing the exact age of this pivotal event has remained a challenge. The intense energy generated by the collision melted the lunar surface, making it unfavourable for the formation of zircon crystals.

As Dr Heck explained, “When the surface was molten like that, zircon crystals couldn’t form and survive. So any crystals on the Moon’s surface must have formed after this lunar magma ocean cooled. Otherwise, they would have been melted, and their chemical signatures would be erased.”

This research was initiated when Bidong Zhang, an assistant researcher at the University of California, Los Angeles, proposed that dating the lunar dust’s crystals might unveil the Moon’s actual age.

Dr Zhang, along with Dr Audrey Bouvier, a professor of experimental planetology at Bayreuth University in Germany, collaborated with Dr Heck and Jennika Greer, a research associate in Earth sciences at the University of Glasgow. Their innovative approach utilised advanced atom probe tomography to examine the crystals’ chemical composition and determine the Moon’s age.

The study marks the first application of atom probe tomography for dating lunar crystals and was conducted using cutting-edge instruments at Northwestern University in Evanston, Illinois.