https://www.npr.org/2024/12/18/nx-s...-35-billion-heres-the-moons-anti-aging-secreta study in the journal Nature argues for the earlier age, saying that the ancient Moon also went through a period when it got hot and partially remelted, producing new rocks about 4.35 billion years ago.
Astronomers have long known that the Earth and Moon are younger than 4.6 billion years, because that's when the solar system got its start.
A huge cloud of dust and gas collapsed inward, forming a new star. Leftover clumps of matter started crashing into each other, glomming together and gradually building up planets.
During this chaotic time, an object the size of Mars smashed into the proto-Earth.
"It would surely have been spectacular," says Nimmo. "It was just so energetic that it's really hard for us to conceive of what it must have looked like."
The last giant impact on Earth is thought to have formed the Moon1. The timing of this event can be determined by dating the different rocks assumed to have crystallized from the lunar magma ocean (LMO). This has led to a wide range of estimates for the age of the Moon between 4.35 and 4.51 billion years ago (Ga), . . . . Here we argue that the frequent occurrence of approximately 4.35-Ga ages among lunar rocks and a spike in zircon ages at about the same time is indicative of a remelting event driven by the Moon’s orbital evolution rather than the original crystallization of the LMO.
On 25 June, Li Chunlai watched eagerly as a capsule carrying the first pieces of the far side of the Moon landed on Earth. “Sample, I finally got you,” he thought, as if speaking to an adversary he had spent years trying to outwit.
That moment capped decades of hard work for Li, deputy chief designer for China’s Chang’e-6 mission, which blasted off to the Moon on 3 May. The 3,200-kilogram lander — about as heavy as a pickup truck — spent two days drilling and scooping material on the lunar surface before sending the samples back to Earth.
That first paper is quite interesting. It appears to resolve discordant estimates for the Moon's age, but also (in my mind) may raise some new issues.Astronuc said:The paper on Nature - Tidally driven remelting around 4.35 billion years ago indicates the Moon is old
https://www.nature.com/articles/s41586-024-08231-0
I have yet to read the paper. I'm curious about the interpretation of the Moon's and Earth's geology.
The main focus of the paper is to explore the processes involved in the Moon's early evolution, particularly how tidal forces may have contributed to its remelting and geological activity shortly after its formation. The study aims to provide insights into the thermal history of the Moon and the implications for its surface and interior structure.
Tidal forces, generated by the gravitational interaction between the Earth and the Moon, create flexing and deformation in the Moon's interior. This flexing generates heat through friction, which can lead to localized melting of the lunar mantle and crust. The paper discusses how these processes may have played a significant role in shaping the Moon's early geological features.
The paper presents a combination of theoretical models and geological evidence from lunar samples, including data from lunar missions. This evidence suggests that the heat generated by tidal forces could explain certain geological features observed on the Moon, such as basalts and the distribution of impact craters, which indicate a history of volcanic activity.
This research has broader implications for understanding the evolution of other celestial bodies, particularly those with similar tidal interactions. It suggests that tidal heating can significantly influence the thermal and geological evolution of moons and planets, potentially affecting their habitability and surface conditions over time.
The study encourages further exploration of tidal heating effects on other moons and planets, as well as the need for more detailed geophysical models to better understand the thermal evolution of celestial bodies. Additionally, it highlights the importance of future lunar missions to gather more data on the Moon's geology and internal structure, which could refine our understanding of its history.