Moon contraction revealed by 10,000 young faults

A study published in The Planetary Science Journal reveals that the Moon is slowly shrinking as its interior cools. By analyzing images from NASA’s Lunar Reconnaissance Orbiter Camera, researchers identified more than 10,000 young faults across the lunar surface.

The contraction has caused the Moon's radius to decrease by approximately 45 meters (148 feet) over the last 400 million to 800 million years. These geological changes manifest as lobate scarps—small, cliff-like steps formed by thrust faults where squeezing forces push sections of the crust upward.

Unlike Earth, which has multiple moving tectonic plates, the Moon consists of a single, rigid outer shell. This structure means that faults are scattered widely across the surface rather than being concentrated in specific zones, and these faults can trigger moonquakes. Understanding these features is considered vital for interpreting lunar history and assessing safety for future lunar exploration.