Scientists have finally answered one of the Moon's biggest mysteries: its inner core. For years, experts debated whether the Moon's core was solid or molten.
Now, a study has settled the question. The inner core of the Moon is solid and has a density similar to iron, researchers say.
Moon's Core and Its Role in the Solar System's History
This discovery is a big step forward in understanding the Moon's history and the early Solar System. A team, led by astronomer Arthur Briaud from the French National Centre for Scientific Research, explains that their findings could help scientists better understand the evolution of the Moon's magnetic field.
They also hope it will provide new insights into the timeline of the Moon's bombardment during the first billion years of the Solar System.
To uncover this information, Briaud and his team relied on data from several space missions and lunar laser-ranging experiments. They used these to study the Moon's characteristics, such as its gravitational relationship with Earth and its density.
Scientists have also used seismic waves from the Apollo missions to learn about the Moon's interior, though the data was not detailed enough to answer the question about its core.
Their findings suggest that the Moon's core behaves similarly to Earth's core. It has a fluid outer layer and a solid inner core. The solid inner core has a radius of about 258 kilometers (160 miles) and makes up 15% of the Moon's total size.
Moon's Magnetic History and Volcanic Regions
The outer core, on the other hand, has a radius of 362 kilometers (225 miles). The inner core's density is about 7,822 kilograms per cubic meter, almost the same as iron.
According to Nature, the study also supports the idea of "mantle overturn," where denser material sinks towards the center while less dense material rises. This process could explain why certain elements are found in volcanic regions on the Moon.
These results could help scientists understand how the Moon's magnetic field began to weaken around 3.2 billion years ago. Such a magnetic field is usually generated by movements inside a planet or moon's core, and this new understanding of the core's composition is key to explaining the Moon's magnetic history.
The team's research offers exciting new information that could also be useful for future missions to the Moon. As humans plan to return to the Moon in the coming years, these findings may help us learn even more about our closest neighbor in space.
