The Moon’s Core: A Solid Ball of Iron

After years of speculation and debate, recent research has provided groundbreaking insight into the composition of the Moon’s inner core. In a study published in May 2023, astronomer Arthur Briaud and his team revealed that the Moon’s inner core is not made of green cheese, as was once humorously suggested, but rather is a solid ball with a density similar to that of iron. This discovery has significant implications for our understanding of the Moon’s history and the evolution of our Solar System.

Exploring the interior composition of celestial bodies like the Moon is a challenging task that requires advanced seismic data analysis. Acoustic waves generated by quakes provide valuable information about the materials inside a planet or moon, enabling scientists to create detailed maps of their interiors. While previous lunar seismic data collected by the Apollo mission provided some insights, the resolution was insufficient to determine the state of the inner core definitively. However, by combining data from space missions and lunar laser ranging experiments, Briaud and his team were able to compile a comprehensive profile of various lunar characteristics.

One of the most significant findings of the study was the confirmation of a solid inner core within the Moon, surrounded by a fluid outer core. The team’s modeling revealed that the outer core has a radius of approximately 362 kilometers, while the inner core’s radius is about 258 kilometers. The density of the inner core was found to be around 7,822 kilograms per cubic meter, closely resembling the density of iron. This Earth-like composition of the Moon’s core sheds new light on its evolutionary history and magnetic field dynamics.

Implications for Lunar Evolution

The presence of a solid inner core in the Moon suggests similarities to Earth’s core structure and provides clues about the Moon’s magnetic field history. It is known that the Moon once had a powerful magnetic field, which began to decline approximately 3.2 billion years ago. Understanding the composition of the lunar core is essential in unraveling the mysteries of why and how the magnetic field dissipated over time. These findings have implications for future lunar exploration missions, as they could potentially lead to seismic verification of the Moon’s core composition.

The recent research on the Moon’s core has provided significant insights into the composition and structure of our celestial neighbor. The discovery of a solid ball of iron at the Moon’s center not only settles long-standing debates but also opens up new avenues for understanding the evolution of the Moon and the broader Solar System. With ongoing advancements in scientific research and technology, we can expect further discoveries that will deepen our knowledge of the mysteries hidden within the Moon and other celestial bodies.