ⓒDaily Post=Image provided/Flickr
ㅣDaily Post = Reporter Kim Jeong-eunㅣThe moon is a very familiar celestial body, but many things remain unclear about its composition and environment.
According to an article published by the French National Center for Scientific Research (CNRS) in the international journal Nature in May 2023, a “solid metal core” exists on the Moon.
ⓒDaily Post=Image provided/Nature (2023)
In fact, research into the internal structure of the Moon has been ongoing for a long time. Seismic data is known to be effective in determining the internal composition of celestial bodies. This is because seismic waves pass through the interior of a celestial body and, by analyzing the way in which the vibration propagates, it is possible to estimate the constituent materials and the structure of the interior of the celestial body.
In a paper published in 2011, an analysis result was derived based on Apollo program seismometer data that “the inner core of a solid is covered by the outer core of a fluid.” At the time, NASA planetary scientist Lenny Weber analyzed seismic data from the Moon and concluded: “The Moon has a solid inner core.”
ⓒDaily Post=Image provided/Scence (2011)
However, the 2011 study was unable to determine what material the inner core was made of due to problems with the seismometer’s accuracy.
As a result, the research team at the French National Center for Scientific Research took a different approach to existing analyses. First, detailed observation data of the Moon (mass, density, rotation method, deformation of the Moon due to tides, variation of the distance between the Earth and the Moon, etc.) were collected through laser distance measurement data. Furthermore, through simulations that assumed various base materials, the material that best matches the observation data was discovered.
As a result of the analysis, it was revealed that the Moon has an “inner core composed of metal with a density close to that of iron (7822 kg/㎥)”.
Image of the interior of the moon (crust, mantle, clay layer between core and mantle, liquid inner core, solid inner core) ⓒDaily Post=Image provided/Nature (2023)
According to this model, the radius of the Moon’s outer core is approximately 362 km. Furthermore, the size of the inner core has a radius of 258 km, which is equivalent to about 15% of the entire volume of the Moon.
It was also revealed that during the formation of the Moon, mantle overturning occurred, in which the composition of the core and mantle changed. The occurrence of mantle overturning helps explain why large amounts of iron exist near the lunar surface.
#material #Moons #core
