New Research Sheds Light on the Composition of the Moon’s Core
In a breakthrough study published in the journal Nature, researchers have determined that the inner core of the Moon is not made of green cheese, as the age-old myth suggests. Instead, it is a solid ball with a density similar to that of iron.
Led by astronomer Arthur Briaud of the French National Centre for Scientific Research, the team conducted an extensive investigation to settle the debate surrounding the state of the Moon’s inner core. By analyzing seismic data collected from previous space missions and lunar laser ranging experiments, the researchers were able to gain insights into the composition and characteristics of the Moon’s core.
The study found that the models closest to what is known about the Moon’s core describe active overturning deep within the lunar mantle. This activity suggests that denser material inside the Moon falls towards the center, while less dense material rises towards the surface. The presence of certain elements in volcanic regions of the Moon supports this theory.
Furthermore, the research team discovered that the Moon’s core bears a striking resemblance to that of Earth. It consists of an outer fluid layer and a solid inner core. The outer core has a radius of approximately 362 kilometers (225 miles), while the inner core has a radius of about 258 kilometers (160 miles) – accounting for approximately 15 percent of the Moon’s entire radius. Notably, the density of the inner core is approximately 7,822 kilograms per cubic meter, similar to that of iron.
Interestingly, the study’s findings align with research conducted in 2011 by NASA Marshall planetary scientist Renee Weber. Using advanced seismological techniques on Apollo data, Weber’s team also suggested the presence of a solid inner core with similar characteristics.
The confirmation of an Earth-like lunar core has important implications for understanding the Moon’s evolution. It was previously known that the Moon had a powerful magnetic field shortly after its formation, which began to decline around 3.2 billion years ago. The composition of the core plays a crucial role in the generation and maintenance of a magnetic field, shedding light on the disappearance of the Moon’s magnetic field.
With plans for future lunar missions in the pipeline, scientists hope that seismic verification of these findings will provide further insights into the Moon’s core and its role in shaping the history of the Solar System.
This article was first published in May 2023 and highlights the significant progress made in our understanding of the Moon’s composition and evolution.