New research suggests the moon could be older than initially estimated

The moon may be more than 100 million years older than some scientists previously thought, according to a new study.

The study was published on Wednesday. journal naturechallenges long-held ideas The moon is thought to have formed about 4.35 billion years ago after an object the size of Mars crashed into the early Earth and created our natural satellite.

That timeline is based on analysis of lunar rock samples taken during NASA's Apollo mission. But new research shows that the moon formed much earlier, about 4.51 billion years ago, and then underwent a dramatic “remelting” phenomenon around the time other scientists thought the moon first formed. It suggests that you have experienced it.

According to the authors, the melting occurred because Earth's constant gravitational pull distorted the moon and made it extremely hot as it moved away from Earth. According to the study, this process altered the moon's surface and hid the moon's true age.

The study's lead author, Francis Nimmo, a professor in the Department of Earth and Planetary Sciences at the University of California, Santa Cruz, said the extreme heating caused the moon's surface to re-melt, effectively “resetting all the clocks” on the moon's rocks. 'There is a possibility.

“So moon rocks don't tell us when the moon formed, but they tell us when subsequent events that heated the moon occurred,” he says.

The scientific community has disagreed for decades about the exact age of the moon. Nimmo and his colleagues are not the first to offer older estimates. This new discovery adds to the growing consensus that there may be more to the moon's history than the Apollo samples revealed.

For example, planetary scientists have wondered how a massive collision occurred 4.35 billion years ago, when most large objects in the history of the solar system were thought to have already come together to form planets. I have had a hard time explaining why the moon was formed.

“Those who studied the Apollo samples had reasonable guesses about the moon's age, but those who modeled how the planets in our solar system formed are wondering why so much material still remains after 200 million years. “It was always difficult to explain why the solar system was still flying,” Nimmo said. “That's the way it is, and the two camps want different ages.”

The adjusted schedule by Nimmo's team may also help explain why. A mineral called zircon found on the moon It was discovered in Apollo's moon rock and is estimated to be approximately 4.5 billion years old. The moon's zircons, like other minerals on the moon, were thought to have crystallized during the moon's extreme temperatures, but their much older age has long puzzled scientists. .

In a new study, Nimmo and his colleagues suggest that the moon's overheating is the product of a process known as “tidal heating.”

“There are certain spots where the moon's orbit can be temporarily thrown off as it gets pushed aside,” Nimmo said. “During that time, the moon can be squeezed and stretched by Earth's gravity, which causes it to heat up.”

Similar tidal heating is thought to occur between Jupiter and its moons. a 2020 survey Researchers have discovered that the gas giant's gravity can stretch and squeeze some of its icy moons to the point where they heat up their interiors and melt rocks into magma. It is believed that this also applies to Jupiter's moon Io.

Recent and upcoming lunar missions could provide better insight into the moon's evolutionary history, Nimmo said. This includes China's Chang'e 6 mission, which collected samples from…

“The evolution of the solar system was very rapid. In just tens of millions of years, all the objects we know today were formed,” Munker said. “That's why we need very good temporal resolution for these very early events and why it's important to understand how the Earth-Moon system formed.”