Moon likely formed 4.51 billion years ago
The new finding should settle a long-standing debate.
Some previous studies have come up with similar estimates, while others have argued for a younger moon that coalesced 150 million to 200 million years after the solar system was born.
The new finding, which was published on Wednesday in the journal Science Advances, should settle this long-standing debate.
"We are really sure that this age is very, very robust," said lead author Melanie Barboni of the University of California, Los Angeles.
The scientists conducted uranium-lead dating on fragments of the mineral zircon extracted from Apollo 14 lunar samples.
Barboni said she is studying more zircons from the 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.
She and her colleagues are eager to learn more about the moon's history and, in turn, the evolution of early Earth and the entire solar system.
It's the second major moon study this week.
On Monday, Israeli scientists suggested that our Earth's constant companion may actually be a melting pot of many mini-moons created by a series of smaller collisions.
Barboni said regardless of how the moon came to be, "you still end up at the end solidifying the moon as we know it today." ■