The research has been published in Nature.
There has been a lot of curiosity about what is Moon made of and there have been several debates about whether its inner core is solid or molten. Now researchers have found that the inner core of the Moon is in fact a solid ball with a density similar to that of iron, Science Alert reported. Well, the new findings open the door to a more accurate understanding of the Moon and our solar system.
A team led by astronomer Arthur Briaud of the French National Centre for Scientific Research in France said, "Our results, question the evolution of the Moon's magnetic field thanks to its demonstration of the existence of the inner core and support a global mantle overturn scenario that brings substantial insights on the timeline of the lunar bombardment in the first billion years of the Solar System."
The report further said that the seismic data effectively examine the inner composition of the objects in the solar system. It said that the way acoustic waves generated by quakes move through and reflect from the material inside a planet or moon can help scientists create a detailed map of the object's interior.
Mr Briaud said, "We happen to have lunar seismic data collected by the Apollo mission, but its resolution is too low to accurately determine the inner core's state. We know there is a fluid outer core, but what it encompasses remains under debate. Models of a solid inner core and an entirely fluid core work equally well with the Apollo data."
Mr Briaud and his colleagues collected data from space missions and lunar laser-ranging experiments to compile a profile of various lunar characteristics. They also conducted modelling with various core types to find which matched most closely with the observational data.
The researchers made several interesting findings. They found that the models that resembled the Moon describe active overturn deep inside the lunar mantle. In simpler terms, it means that denser material inside the Moon falls towards the centre, and less dense material rises upwards, a Science Alert report said.
They also found that the lunar core is very similar to that of Earth- with an outer fluid layer and a solid inner core. Getting into the details, the researchers shared that the outer core has a radius of about 362 kilometres (225 miles), and the inner core has a radius of about 258 kilometres (160 miles). That's about 15 per cent of the entire radius of the Moon. The inner core, the team found, also has a density of about 7,822 kilograms per cubic meter. That's very close to the density of iron.
The research has been published in Nature.