It turns out the moon is older than many scientists suspected: a ripe 4.51 billion years old.
That’s the newest estimate, thanks to rocks and soil collected by the Apollo 14 moonwalkers in 1971.
A research team reported Wednesday that the moon formed within 60 million years of the birth of the solar system. Previous estimates ranged within 100 million years, all the way out to 200 million years after the solar system’s creation, not quite 4.6 billion years ago.
The scientists conducted uranium-lead dating on fragments of the mineral zircon extracted from Apollo 14 lunar samples. The pieces of zircon were minuscule ” no bigger than a grain of sand.
“Size doesn’t matter, they record amazing information nonetheless!” lead author Melanie Barboni of the University of California, Los Angeles, said in an email.
She noted that the moon holds “so much magic … the key to understand how our beautiful Earth formed and evolved.”
The moon was created from debris knocked off from Earth, which itself is thought to be roughly 4.54 billion years old.
Some of the eight zircon samples were used in a previous study, also conducted at UCLA, that utilized more limited techniques. Barboni said she is studying more zircons from Apollo 14 samples, but doesn’t expect it to change her estimate of 4.51 billion years for the moon’s age, possibly 4.52 billion years at the most.
“It would be more a double-checking than anything else,” she explained. She and her colleagues ” whose work appeared Wednesday in the journal Science Advances ” are eager to learn more about the moon’s history and, in turn, the evolution of early Earth and the entire solar system.