Overview

• A Nature paper led by Arthur Briaud used integrated seismic, gravity and lunar ranging data to map the Moon’s two-layer core.
• The interior features a solid inner sphere about 258 km in radius with a density near 7,822 kg/m³ and a roughly 362 km fluid outer shell.
• The core measurements support scenarios in which lunar interior convection sustained a magnetic field that later shut down as the Moon cooled.
• Researchers combined legacy Apollo seismology with newer mission data and advanced simulations to overcome limitations of individual datasets.
• A companion analysis of Mars from InSight seismic data suggests a possible solid core but remains provisional pending further study.