Seismic and orbital data suggest the Moon has a small, partially molten iron core about 350 km in radius. That’s just 20% of the lunar radius. Density is higher than surrounding mantle. The core contributes to magnetic anomalies. It formed early in lunar history, likely from differentiation. Despite its small size, it influenced thermal evolution and tectonic activity. Understanding core size informs planetary formation theories.
It matters because the core affects geophysics, magnetism, and thermal modeling.
It also offers insight into how small bodies differentiate internally. Comparative planetology benefits from this knowledge.
The Moon’s core is less than half the size of Mercury’s core.
NASA [nasa.gov]