The moon is much older than previously thought. That’s what scientists say in a new study published in the scientific journal in October 2023 Geochemical Perspectives Letters.
An Apollo memento from 1972 proves to be the key to the new discovery
To find out the age of the moon, scientists examined crystals from a sample of the moon. In 1972, astronauts from the Apollo 17 mission returned a soil sample to Earth. “But only now do we have the techniques to perform precise analyses,” said Dieter Eichheim, co-author of the study.
How was the moon formed?
Several billion years ago, a Mars-sized object collided with Earth. This collision released so much energy that some of the rocks that would eventually form the Moon’s surface melted. An important fact, because it means that the crystals that the Apollo astronauts took with them to Earth did not form until after the Moon was formed.
If we know the age of those crystals, we also know at least how old the Moon must be. To determine the age of the moon’s crystals, the research team magnified the atoms. Specifically, the number of atoms that underwent radioactive decay was examined. This radiometric dating allowed the research team to determine the age of the crystals.
The moon is this old
“Radiometric dating is a bit like an hourglass,” says Philip Heck of the Field Museum, lead author of the study. ‘In an hourglass, sand flows from one glass sphere to another, with the passage of time indicated by the accumulation of sand in the lower sphere. Radioactive dating works in a similar way. We count the number of original atoms and the number of daughter atoms they transformed into.’ Scientists know how much time goes into this process, so they can make a good estimate of the age of the samples. So also say something about the age of the Moon.
They concluded that the Moon is at least 4.46 billion years old. This makes the Moon 40 million years older than previously assumed.
Willick Van Doorn studied journalism, traveled the world for a while, and eventually ended up in the editorial offices of Quest, National Geographic, and Runner’s World across the United States, Australia, and New Zealand. She is interested in the world, prefers to travel every month and always takes her running shoes with her.
