The Moon Is Still Shrinking, Novel Map Reveals Potential Hazards for Future Missions

For decades, the Moon was considered a geologically inactive body. However, recent research has revealed that our celestial neighbor is still shrinking, leading to seismic activity and the formation of unique geological features. A newly released global map details thousands of these features, called Minor Mare Ridges (SMRs), offering crucial insights for future lunar missions like NASA’s Artemis program.

Lunar Shrinkage and Moonquakes

Unlike Earth, which has a fragmented crust composed of tectonic plates, the Moon possesses a single, continuous crust. The shrinking of the Moon is driven by the unhurried cooling of its interior core. As the core cools, the Moon’s surface wrinkles and fractures under tremendous pressure, much like the skin of a grape turning into a raisin. This process generates what are known as moonquakes.

Mapping the Wrinkles: Small Mare Ridges

Scientists led by Cole Nypaver and Tom Watters have identified 1,114 new segments of SMRs within the lunar maria – the dark, basaltic plains visible from Earth. Published in The Planetary Science Journal, this research brings the total number of documented SMRs to 2,634. The average age of these ridges is approximately 124 million years, relatively young in geological terms, indicating ongoing tectonic activity.

Implications for Future Lunar Exploration

The widespread distribution of SMRs suggests that the Moon’s shrinking and associated tectonic activity are occurring globally. This has significant implications for the safety of future lunar missions. Moonquakes, triggered by the stress on the lunar crust, can last longer than earthquakes on Earth due to the Moon’s dry and rigid structure, potentially causing substantial damage to infrastructure and posing risks to astronauts.

Understanding the locations of these active fault lines is crucial for identifying safe landing sites. The new map of lunar shrinkage and seismic activity will help scientists determine areas less prone to tectonic disturbances, mitigating risks for missions like NASA’s Artemis program, which aims to return humans to the Moon.

Expert Insights

Bruce Campbell, a Senior Scientist at the Smithsonian’s Center for Earth and Planetary Studies at the National Air and Space Museum, has extensively researched the geology of the Moon, Mars, Venus, and icy moons. His function utilizes radar observations to probe beneath the surfaces of these celestial bodies, revealing subsurface features and geological processes. Thomas Watters is also affiliated with the Smithsonian Institution’s Center for Earth and Planetary Studies. His research focuses on planetary tectonics and surface processes.

The Dynamic Moon

The Moon, once believed to be geologically inert, is now recognized as a dynamic world undergoing ongoing changes. NASA’s lunar science program continues to unravel the mysteries of our closest celestial neighbor, providing valuable insights into the formation and evolution of the solar system and paving the way for safe and sustainable lunar exploration.